BIS-ester and amide cationic lipids

Abstract

The present invention provides, in part, cationic lipid compounds of Formulae (I), (II), (III), (IV), (V), or (VI) or a pharmaceutically acceptable salt thereof. The compounds provided herein can be useful for delivery and expression of mRNA and encoded protein, e.g., as a component of liposomal delivery vehicle, and accordingly can be useful for treating various diseases, disorders and conditions, such as those associated with deficiency of one or more proteins.

Description

1 BIS-ESTER AND AMIDE CATIONIC LIPIDS CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims priority to European Patent Application No. 24315308.7, filed June 26th, 2024, which is incorporated by reference in its entirety. 5 BACKGROUND

[0002] Delivery of nucleic acids has been explored extensively as a potential therapeutic option for certain disease states. In particular, messenger RNA (mRNA) therapy has become an increasingly important option for the prevention and treatment of various 10 diseases (e.g. in the use of vaccines).

[0003] Efficient delivery of liposome-encapsulated nucleic acids remains an active area of research. The cationic lipid component of liposomes encapsulating nucleic acids plays an important role in facilitating effective encapsulation of the nucleic acid during the loading of liposomes. In addition, cationic lipids may play an important role in the efficient release of the 15 nucleic acid cargo from the liposome into the cytoplasm of a target cell. Various cationic lipids suitable for in vivo use have been discovered. However, there remains a need to identify lipids that can be synthesized efficiently and cheaply without the formation of potentially toxic by-products.

[0004] There are cationic lipids that contain a cyclic ring structure as a central core (lipidoids 20 like cKK-E12 - structure shown below):SUMMARY OF THE INVENTION25

[0005] The present invention provides, among other things, a novel class of cationic lipid compounds for in vivo delivery of therapeutic agents, such as nucleic acids. It is contemplated that these compounds are capable of highly effective in vivo delivery of the therapeutic agents and vaccines while maintaining a favorable safety profile. Lipid nanoparticles comprising the cationic lipids of the present invention also exhibit enhanced2 thermostability, which is beneficial for the development of the corresponding therapeutic agents and vaccines.

[0006] The cationic lipids of the present invention comprise cleavable groups (e.g., esters) that are contemplated to improve biodegradability and thus contribute to their favorable 5 safety profile.

[0007] In an aspect, provided herein are cationic lipids having a structure according to Formula (I):Formula (I), 10 or a pharmaceutically acceptable salt thereof, wherein: R1is selected from hydrogen, or optionally substituted (C1-C6)alkyl; R2is selected from -OH, -NH2, optionally substituted (C1-C6)alkyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted (C1-C3)alkylene- 15 optionally substituted aryl, or optionally substituted (C1-C3)alkylene-optionally substituted heteroaryl; b and c are integers that are each independently selected from 0, 1, 2, 3, or 4; a and d are integers that are each independently selected from 1, 2, 3, 4, 5 or 6; each Y1is independently selected from hydrogen or -OH; 20 each R4is independently selected from hydrogen or optionally substituted (C1- C6)alkyl. R3A, R3B, R3C, and R3Dare each independently selected from optionally substituted (C1-C25)alkyl, optionally substituted (C2-C25)alkenyl, or -W1-X1; each W1is independently selected from a covalent bond, optionally substituted (C1- 25 C10)alkylene or optionally substituted (C2-C10)alkenylene; and each X1is independently selected from -(*C=O)-O-optionally substituted (C3-C25)alkyl, -(*C=O)-O-optionally substituted (C3-C25)alkenyl, -*O-(C=O)-optionally substituted3 (C3-C25)alkyl, or -*O-(C=O)-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond.

[0008] In an aspect, provided herein are cationic lipids having a structure according to Formula (II): 5Formula (II) or a pharmaceutically acceptable salt thereof, wherein: e and f are integers that are each independently selected from 1, 2, 3, 4, 5 or 6; 10 each Y2is independently selected from hydrogen or -OH; R6is selected from hydrogen or optionally substituted (C1-C6)alkyl; R7is selected from optionally substituted (C1-C6)alkylene-R8or R8; R8is selected from optionally substituted aryl, optionally substituted heteroaryl. R5A, R5B, R5C, and R5Dare each independently selected from optionally substituted 15 (C1-C25)alkyl, optionally substituted (C2-C25)alkenyl, or -W1-X1; each W1is independently selected from a covalent bond, optionally substituted (C1- C10)alkylene or optionally substituted (C2-C10)alkenylene; and each X1is independently selected from -(*C=O)-O-optionally substituted (C3-C25)alkyl, -(*C=O)-O-optionally substituted (C3-C25)alkenyl, -*O-(C=O)-optionally substituted20(C3-C25)alkyl, or -*O-(C=O)-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond.

[0009] In an aspect, provided herein are cationic lipids having a structure according to Formula (III):4Formula (III) or a pharmaceutically acceptable salt thereof, wherein: 5 h and i are integers that are each independently selected from 1, 2, 3 or 4; g and j are integers that are each independently selected from 1, 2, 3, 4, 5 or 6; k is an integer selected from 1, 2, 3, 4, 5, or 6; m is an integer selected from 0, 1, 2, 3, 4, 5, or 6; each Y3is independently selected from hydrogen or -OH; 10 X2is selected from H, NH2 and F; R10is selected from an optionally substituted aryl, optionally substituted heteroaryl, optionally substituted (C1-C25)alkyl or optionally substituted (C2-C25)alkenyl; R9A, R9B, R9C, and R9Dare each independently selected from optionally substituted (C1-C25)alkyl, optionally substituted (C2-C25)alkenyl, or -W1-X1; 15 each W1is independently selected from a covalent bond, optionally substituted (C1- C10)alkylene or optionally substituted (C2-C10)alkenylene; and each X1is independently selected from -(*C=O)-O-optionally substituted (C3-C25)alkyl, -(*C=O)-O-optionally substituted (C3-C25)alkenyl, -*O-(C=O)-optionally substituted (C3-C25)alkyl, or -*O-(C=O)-optionally substituted (C3-C25)alkenyl, wherein the atom marked 20 with a * is connected to W1or -CH(Y3)- when W1is a covalent bond.

[0010] In an aspect, provided herein are cationic lipids having a structure according to Formula (IV):5Formula (IV) wherein: p and q are integers that are each independently selected from 1, 2, 3, 4, 5 or 6; 5 each Y4is independently selected from hydrogen or -OH; R11is selected from hydrogen or optionally substituted (C1-C6)alkyl; X3is selected from a covalent bond, -O-, or -N(R13)-; R13is selected from hydrogen or optionally substituted (C1-C6)alkyl; R12A, R12B, R12C, and R12Dare each independently selected from optionally substituted10(C1-C25)alkyl, optionally substituted (C2-C25)alkenyl, or -W1-X1; each W1is independently selected from a covalent bond, optionally substituted (C1- C10)alkylene or optionally substituted (C2-C10)alkenylene; and each X1is independently selected from -(*C=O)-O-optionally substituted (C3-C25)alkyl, -(*C=O)-O-optionally substituted (C3-C25)alkenyl, -*O-(C=O)-optionally substituted15(C3-C25)alkyl, or -*O-(C=O)-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond.

[0011] In an aspect, provided herein are cationic lipids having a structure according to Formula (V):20 Formula (V)6 or a pharmaceutically acceptable salt thereof, wherein: r and s are integers that are each independently selected from 1, 2, 3, 4, 5 or 6; each Y5is independently selected from hydrogen or -OH; 5 R15is optionally substituted (C1-C3)alkylene-optionally substituted bicyclic heteroaryl; R16is hydrogen; R14A, R14B, R14C, and R14Dare each independently selected from optionally substituted (C5-C25)alkyl, optionally substituted (C5-C25)alkenyl, or -W1-X1; each W1is independently selected from a covalent bond, optionally substituted (C1- 10 C10)alkylene or optionally substituted (C2-C10)alkenylene; and each X1is independently selected from -(*C=O)-O-optionally substituted (C3-C25)alkyl, -(*C=O)-O-optionally substituted (C3-C25)alkenyl, -*O-(C=O)-optionally substituted (C3-C25)alkyl, or -*O-(C=O)-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. 15

[0012] In an aspect, provided herein are cationic lipids having a structure according to Formula (VI):Formula (VI) or a pharmaceutically acceptable salt thereof, 20 wherein: t and u are integers that are each independently selected from 1, 2, 3, 4, 5 or 6; each Y6is independently selected from hydrogen or -OH; R19is selected from optionally substituted (C1-C3)alkylene-optionally substituted thiazolyl and optionally substituted (C1-C3)alkylene-substituted phenyl, wherein the phenyl is 25 substituted with one or more halogen atoms (e.g. -F); R18A, R18B, R18C, and R18Dare each independently selected from optionally substituted (C5-C25)alkyl, optionally substituted (C5-C25)alkenyl, or -W1-X1; each W1is independently selected from a covalent bond, optionally substituted (C1- C10)alkylene or optionally substituted (C2-C10)alkenylene; and7

[0013] each X1is independently selected from -(*C=O)-O-optionally substituted (C3-C25)alkyl, -(*C=O)-O-optionally substituted (C3-C25)alkenyl, -*O-(C=O)-optionally substituted (C3-C25)alkyl, or -*O-(C=O)-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond.In an 5 aspect, provided herein are cationic lipids that are pharmaceutically acceptable salts of Formula (I).

[0014] In an aspect, provided herein are cationic lipids that are pharmaceutically acceptable salts of Formula (II).

[0015] In an aspect, provided herein are cationic lipids that are pharmaceutically 10 acceptable salts of Formula (III).

[0016] In an aspect, provided herein are cationic lipids that are pharmaceutically acceptable salts of Formula (IV).

[0017] In an aspect, provided herein are cationic lipids that are pharmaceutically acceptable salts of Formula (V). 15

[0018] In an aspect, provided herein are cationic lipids that are pharmaceutically acceptable salts of Formula (VI).

[0019] In an aspect, provided herein are compositions comprising the cationic lipid of the present invention or a pharmaceutically acceptable salt thereof, one or more non-cationic lipids, one or more cholesterol-based lipids and one or more PEG-modified lipids. In an 20 aspect, the composition is a lipid nanoparticle, optionally a liposome.

[0020] In an aspect, the compositions comprising the cationic lipids of the present invention may be used in therapy.

[0021] The inventors of the present invention have surprisingly found that cationic lipids made from commercially available acyclic linkers have high levels of peptide or protein 25 expression when delivering mRNA encoding said peptide or protein while having a reduced size and complexity. This reduced size and complexity allows for the development of new lipid analogues more speedily and the claimed cationic lipids are also advantageous when it comes to downstream scale up and manufacturing as compared to earlier lipidoid cationic lipids. 30 DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS Definitions

[0022] In order for the present invention to be more readily understood, certain terms 35 are first defined below. Additional definitions for the following terms and other terms are set forth throughout the specification. The publications and other reference materials referenced8 herein to describe the background of the invention and to provide additional detail regarding its practice are hereby incorporated by reference.

[0023] Amino acid: As used herein, the term “amino acid,” in its broadest sense, refers to any compound and / or substance that can be incorporated into a polypeptide chain. 5 In some embodiments, an amino acid has the general structure H2N–C(H)(R)–COOH. In some embodiments, an amino acid is a naturally occurring amino acid. In some embodiments, an amino acid is a synthetic amino acid; in some embodiments, an amino acid is a d-amino acid; in some embodiments, an amino acid is an l-amino acid. “Standard amino acid” refers to any of the twenty standard l-amino acids commonly found in naturally 10 occurring peptides. “Nonstandard amino acid” refers to any amino acid, other than the standard amino acids, regardless of whether it is prepared synthetically or obtained from a natural source. As used herein, “synthetic amino acid” encompasses chemically modified amino acids, including but not limited to salts, amino acid derivatives (such as amides), and / or substitutions. Amino acids, including carboxy- and / or amino-terminal amino acids in 15 peptides, can be modified by methylation, amidation, acetylation, protecting groups, and / or substitution with other chemical groups that can change the peptide’s circulating half-life without adversely affecting their activity. Amino acids may participate in a disulfide bond. Amino acids may comprise one or posttranslational modifications, such as association with one or more chemical entities (e.g., methyl groups, acetate groups, acetyl groups, 20 phosphate groups, formyl moieties, isoprenoid groups, sulfate groups, polyethylene glycol moieties, lipid moieties, carbohydrate moieties, biotin moieties, etc.). The term “amino acid” is used interchangeably with “amino acid residue,” and may refer to a free amino acid and / or to an amino acid residue of a peptide. It will be apparent from the context in which the term is used whether it refers to a free amino acid or a residue of a peptide. 25

[0024] Aromatic Amino Acid or Residue: As used herein, the term “aromatic amino acid or residue” refers to a hydrophilic or hydrophobic amino acid or residue having a side chain that includes at least one aromatic or heteroaromatic ring. Aromatic amino acids or residues include L-amino acids, D-amino acids or racemates. Genetically encoded aromatic amino acids include L-Phe (F), L-Tyr (Y), L-His (H) and L-Trp (W). Although owing to the 30 pKa of its heteroaromatic nitrogen atom L-His (H) is sometimes classified as a basic residue, herein histidine is classified as an aromatic residue as its side chain includes a heteroaromatic ring. Examples of aromatic amino acids include the following:9.

[0025] Animal: As used herein, the term “animal” refers to any member of the animal kingdom. In some embodiments, “animal” refers to humans, at any stage of development. In some embodiments, “animal” refers to non-human animals, at any stage of development. 5 In certain embodiments, the non-human animal is a mammal (e.g., a rodent, a mouse, a rat, a rabbit, a monkey, a dog, a cat, a sheep, a bovine, a primate, and / or a pig). In some embodiments, animals include, but are not limited to, mammals, birds, reptiles, amphibians, fish, insects, and / or worms. In some embodiments, an animal may be a transgenic animal, genetically-engineered animal, and / or a clone. 10

[0026] Approximately or about: As used herein, the term “approximately” or “about,” as applied to one or more values of interest, refers to a value that is similar to a stated reference value. In certain embodiments, the term “approximately” or “about” refers to a range of values that fall within 25%, 20%, 19%, 18%, 17%, 16%, 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, or less in either direction (greater than 15 or less than) of the stated reference value unless otherwise stated or otherwise evident from the context (except where such number would exceed 100% of a possible value).

[0027] Biologically active: As used herein, the term “biologically active” refers to a characteristic of any agent that has activity in a biological system, and particularly in an organism. For instance, an agent that, when administered to an organism, has a biological 20 effect on that organism, is considered to be biologically active.

[0028] Delivery: As used herein, the term “delivery” encompasses both local and systemic delivery. For example, delivery of mRNA encompasses situations in which an mRNA is delivered to a target tissue and the encoded protein is expressed and retained within the target tissue (also referred to as “local distribution” or “local delivery”), and 25 situations in which an mRNA is delivered to a target tissue and the encoded protein is expressed and secreted into patient’s circulation system (e.g., serum) and systematically distributed and taken up by other tissues (also referred to as “systemic distribution” or “systemic delivery”).

[0029] Expression: As used herein, “expression” of a nucleic acid sequence refers to30translation of an mRNA into a polypeptide, assemble multiple polypeptides into an intact protein (e.g., enzyme) and / or post-translational modification of a polypeptide or fully10 assembled protein (e.g., enzyme). In this application, the terms “expression” and “production,” and grammatical equivalents thereof, are used interchangeably.

[0030] Functional: As used herein, a “functional” biological molecule is a biological molecule in a form in which it exhibits a property and / or activity by which it is characterized. 5

[0031] Half-life: As used herein, the term “half-life” is the time required for a quantity such as nucleic acid or protein concentration or activity to fall to half of its value as measured at the beginning of a time period.

[0032] Helper lipid: The term “helper lipid” as used herein refers to any neutral or zwitterionic lipid material including cholesterol. Without wishing to be held to a particular 10 theory, helper lipids may add stability, rigidity, and / or fluidity within lipid bilayers / nanoparticles.

[0033] Improve, increase, or reduce: As used herein, the terms “improve,” “increase,” or “reduce,” or grammatical equivalents, indicate values that are relative to a baseline measurement, such as a measurement in the same individual prior to initiation of the 15 treatment described herein, or a measurement in a control subject (or multiple control subject) in the absence of the treatment described herein. A “control subject” is a subject afflicted with the same form of disease as the subject being treated, who is about the same age as the subject being treated.

[0034] In Vitro: As used herein, the term “in vitro” refers to events that occur in an 20 artificial environment, e.g., in a test tube or reaction vessel, in cell culture, etc., rather than within a multi-cellular organism.

[0035] In Vivo: As used herein, the term “in vivo” refers to events that occur within a multi-cellular organism, such as a human and a non-human animal. In the context of cell- based systems, the term may be used to refer to events that occur within a living cell (as 25 opposed to, for example, in vitro systems).

[0036] Isolated: As used herein, the term “isolated” refers to a substance and / or entity that has been (1) separated from at least some of the components with which it was associated when initially produced (whether in nature and / or in an experimental setting), and / or (2) produced, prepared, and / or manufactured by the hand of man. isolated 30 substances and / or entities may be separated from about 10%, about 20%, about 30%, about 40%, about 50%, about 60%, about 70%, about 80%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, about 99%, or more than about 99% of the other components with which they were initially associated. In some embodiments, isolated agents are about 80%, about 85%, about 90%, about 91%, about 35 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, about 99%, or more than about 99% pure. As used herein, a substance is “pure” if it is substantially free of11 other components. As used herein, calculation of percent purity of isolated substances and / or entities should not include excipients (e.g., buffer, solvent, water, etc.).

[0037] Liposome: As used herein, the term “liposome” refers to any lamellar, multilamellar, or solid nanoparticle vesicle. Typically, a liposome as used herein can be 5 formed by mixing one or more lipids or by mixing one or more lipids and polymer(s). In some embodiments, a liposome suitable for the present invention contains a cationic lipid(s) and optionally non-cationic lipid(s), optionally cholesterol-based lipid(s), and / or optionally PEG- modified lipid(s).

[0038] messenger RNA (mRNA): As used herein, the term “messenger RNA 10 (mRNA)” or “mRNA” refers to a polynucleotide that encodes at least one polypeptide. mRNA as used herein encompasses both modified and unmodified RNA. The term “modified mRNA” related to mRNA comprising at least one chemically modified nucleotide. mRNA may contain one or more coding and non-coding regions. mRNA can be purified from natural sources, produced using recombinant expression systems and optionally purified, 15 chemically synthesized, etc. Where appropriate, e.g., in the case of chemically synthesized molecules, mRNA can comprise nucleoside analogs such as analogs having chemically modified bases or sugars, backbone modifications, etc. An mRNA sequence is presented in the 5’ to 3’ direction unless otherwise indicated. In some embodiments, an mRNA is or comprises natural nucleosides (e.g., adenosine, guanosine, cytidine, uridine); nucleoside 20 analogs (e.g., 2-aminoadenosine, 2-thiothymidine, inosine, pyrrolo-pyrimidine, 3-methyl adenosine, 5-methylcytidine, C5 propynyl-cytidine, C5 propynyl-uridine, 2-aminoadenosine, C5-bromouridine, C5-fluorouridine, C5-iodouridine, C5-propynyl-uridine, C5-propynyl- cytidine, C5-methylcytidine, 2-aminoadenosine, 7-deazaadenosine, 7-deazaguanosine, 8- oxoadenosine, 8-oxoguanosine, O(6)-methylguanine, and 2-thiocytidine); chemically 25 modified bases; biologically modified bases (e.g., methylated bases); intercalated bases; modified sugars (e.g., 2’-fluororibose, ribose, 2’-deoxyribose, arabinose, and hexose); and / or modified phosphate groups (e.g., phosphorothioates and 5’-N-phosphoramidite linkages).

[00039] Nucleic acid: As used herein, the term “nucleic acid,” in its broadest sense,refers to any compound and / or substance that is or can be incorporated into a 30 polynucleotide chain. In some embodiments, a nucleic acid is a compound and / or substance that is or can be incorporated into a polynucleotide chain via a phosphodiester linkage. In some embodiments, “nucleic acid” refers to individual nucleic acid residues (e.g., nucleotides and / or nucleosides). In some embodiments, “nucleic acid” refers to a polynucleotide chain comprising individual nucleic acid residues. In some embodiments, 35 “nucleic acid” encompasses RNA as well as single and / or double-stranded DNA and / or cDNA. In some embodiments, “nucleic acid” encompasses ribonucleic acids (RNA),12 including but not limited to any one or more of interference RNAs (RNAi), small interfering RNA (siRNA), short hairpin RNA (shRNA), antisense RNA (aRNA), messenger RNA (mRNA), modified messenger RNA (mmRNA), long non-coding RNA (lncRNA), micro-RNA (miRNA) multimeric coding nucleic acid (MCNA), polymeric coding nucleic acid (PCNA), 5 guide RNA (gRNA) and CRISPR RNA (crRNA). In some embodiments, “nucleic acid” encompasses deoxyribonucleic acid (DNA), including but not limited to any one or more of single-stranded DNA (ssDNA), double-stranded DNA (dsDNA) and complementary DNA (cDNA). In some embodiments, “nucleic acid” encompasses both RNA and DNA. In embodiments, DNA may be in the form of antisense DNA, plasmid DNA, parts of a plasmid 10 DNA, pre-condensed DNA, a product of a polymerase chain reaction (PCR), vectors (e.g., P1, PAC, BAC, YAC, artificial chromosomes), expression cassettes, chimeric sequences, chromosomal DNA, or derivatives of these groups. In embodiments, RNA may be in the form of messenger RNA (mRNA), ribosomal RNA (rRNA), signal recognition particle RNA (7 SL RNA or SRP RNA), transfer RNA (tRNA), transfer-messenger RNA (tmRNA), small 15 nuclear RNA (snRNA), small nucleolar RNA (snoRNA), SmY RNA, small Cajal body-specific RNA (scaRNA), guide RNA (gRNA), ribonuclease P (RNase P), Y RNA, telomerase RNA component (TERC), spliced leader RNA (SL RNA), antisense RNA (aRNA or asRNA), cis- natural antisense transcript (cis-NAT), CRISPR RNA (crRNA), long noncoding RNA (lncRNA), micro-RNA (miRNA), piwi-interacting RNA (piRNA), small interfering RNA 20 (siRNA), transacting siRNA (tasiRNA), repeat associated siRNA (rasiRNA), 73K RNA, retrotransposons, a viral genome, a viroid, satellite RNA, or derivatives of these groups. In some embodiments, a nucleic acid is a mRNA encoding a protein such as an enzyme.

[0040] Patient: As used herein, the term “patient” or “subject” refers to any organism to which a provided composition may be administered, e.g., for experimental, diagnostic, 25 prophylactic, cosmetic, and / or therapeutic purposes. Typical patients include animals (e.g., mammals such as mice, rats, rabbits, non-human primates, and / or humans). In some embodiments, a patient is a human. A human includes pre- and post-natal forms.

[0041] Pharmaceutically acceptable: The term “pharmaceutically acceptable,” as used herein, refers to substances that, within the scope of sound medical judgment, are 30 suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit / risk ratio.

[0042] Pharmaceutically acceptable salt: Pharmaceutically acceptable salts are well known in the art. For example, S. M. Berge et al., describes pharmaceutically acceptable 35 salts in detail in J. Pharmaceutical Sciences (1977) 66:1-19. Pharmaceutically acceptable salts of the compounds of this invention include those derived from suitable inorganic and13 organic acids and bases. Examples of pharmaceutically acceptable, non-toxic acid addition salts are salts of an amino group formed with inorganic acids such as hydrochloric acid, hydrobromic acid, phosphoric acid, sulfuric acid, and perchloric acid or with organic acids such as acetic acid, oxalic acid, maleic acid, tartaric acid, citric acid, succinic acid, or 5 malonic acid, or by using other methods used in the art such as ion exchange. Other pharmaceutically acceptable salts include adipate, alginate, ascorbate, aspartate, benzenesulfonate, benzoate, bisulfate, borate, butyrate, camphorate, camphorsulfonate, citrate, cyclopentanepropionate, digluconate, dodecylsulfate, ethanesulfonate, formate, fumarate, glucoheptonate, glycerophosphate, gluconate, hemisulfate, heptanoate, 10 hexanoate, hydroiodide, 2-hydroxy-ethanesulfonate, lactobionate, lactate, laurate, lauryl sulfate, malate, maleate, malonate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, oleate, oxalate, palmitate, pamoate, pectinate, persulfate, 3-phenylpropionate, phosphate, picrate, pivalate, propionate, stearate, succinate, sulfate, tartrate, thiocyanate, p- toluenesulfonate, undecanoate, valerate salts, and the like. Salts derived from appropriate 15 bases include alkali metal, alkaline earth metal, ammonium and N+(C1-4alkyl)4salts. Representative alkali or alkaline earth metal salts include sodium, lithium, potassium, calcium, magnesium, and the like. Further pharmaceutically acceptable salts include, when appropriate, nontoxic ammonium. quaternary ammonium, and amine cations formed using counterions such as halide, hydroxide, carboxylate, sulfate, phosphate, nitrate, sulfonate, 20 and aryl sulfonate. Further pharmaceutically acceptable salts include salts formed from the quarternization of an amine using an appropriate electrophile, e.g., an alkyl halide, to form a quarternized alkylated amino salt.

[0043] Systemic distribution or delivery: As used herein, the terms “systemic distribution” or “systemic delivery,” or grammatical equivalents thereof, refer to a delivery or 25 distribution mechanism or approach that affect the entire body or an entire organism. Typically, systemic distribution or delivery is accomplished via body’s circulation system, e.g., blood stream. Compared to the definition of “local distribution or delivery.”

[0044] Subject: As used herein, the term “subject” refers to a human or any non- human animal (e.g., mouse, rat, rabbit, dog, cat, cattle, swine, sheep, horse or primate). A 30 human includes pre- and post-natal forms. In many embodiments, a subject is a human being. A subject can be a patient, which refers to a human presenting to a medical provider for diagnosis or treatment of a disease. The term “subject” is used herein interchangeably with “individual” or “patient.” A subject can be afflicted with or is susceptible to a disease or disorder but may or may not display symptoms of the disease or disorder. 35

[0045] Substantially: As used herein, the term “substantially” refers to the qualitative condition of exhibiting total or near-total extent or degree of a characteristic or property of14 interest. One of ordinary skill in the biological arts will understand that biological and chemical phenomena rarely, if ever, go to completion and / or proceed to completeness or achieve or avoid an absolute result. The term “substantially” is therefore used herein to capture the potential lack of completeness inherent in many biological and chemical 5 phenomena.

[0046] Target tissues: As used herein, the term “target tissues” refers to any tissue that is affected by a disease to be treated. In some embodiments, target tissues include those tissues that display disease-associated pathology, symptom, or feature.

[0047] Therapeutically effective amount: As used herein, the term “therapeutically 10 effective amount” of a therapeutic agent means an amount that is sufficient, when administered to a subject suffering from or susceptible to a disease, disorder, and / or condition, to treat, diagnose, prevent, and / or delay the onset of the symptom(s) of the disease, disorder, and / or condition. It will be appreciated by those of ordinary skill in the art that a therapeutically effective amount is typically administered via a dosing regimen 15 comprising at least one unit dose.

[0048] Treating: As used herein, the term “treat,” “treatment,” or “treating” refers to any method used to partially or completely alleviate, ameliorate, relieve, inhibit, prevent, delay onset of, reduce severity of and / or reduce incidence of one or more symptoms or features of a particular disease, disorder, and / or condition. Treatment may be administered 20 to a subject who does not exhibit signs of a disease and / or exhibits only early signs of the disease for the purpose of decreasing the risk of developing pathology associated with the disease. Chemical definitions 25

[0049] Acyl: As used herein, the term “acyl” refers to RZ-(C=O)-, wherein RZis, for example, any alkyl, alkenyl, alkynyl, heteroalkyl or heteroalkylene.

[0050] Aliphatic: As used herein, the term aliphatic refers to C1-C50 hydrocarbons and includes both saturated and unsaturated hydrocarbons. An aliphatic may be linear, branched, or cyclic. For example, C1-C20 aliphatics can include C1-C20 alkyls (e.g., linear or 30 branched C1-C20 saturated alkyls), C2-C20 alkenyls (e.g., linear or branched C4-C20 dienyls, linear or branched C6-C20 trienyls, and the like), and C2-C20 alkynyls (e.g., linear or branched C2-C20 alkynyls). C1-C20 aliphatics can include C3-C20 cyclic aliphatics (e.g., C3-C20 cycloalkyls, C4-C20 cycloalkenyls, or C8-C20 cycloalkynyls). In certain embodiments, the aliphatic may comprise one or more cyclic aliphatic and / or one or more heteroatoms such as 35 oxygen, nitrogen, or sulfur and may optionally be substituted with one or more substituents such as alkyl, halo, alkoxyl, hydroxy, amino, aryl, ether, ester or amide. An aliphatic group is15 unsubstituted or substituted with one or more substituent groups as described herein. For example, an aliphatic may be substituted with one or more (e.g., 1, 2, 3, 4, 5, or 6 independently selected substituents) of halogen, -COR’’, -CO2H, -CO2R’’, -CN, -OH, -OR’’, - OCOR’, -OCO2R’’, -NH2, -NHR’’, -N(R’’)2, -SR’’ or-SO2R’’, wherein each instance of R’’ 5 independently is C1-C20 aliphatic (e.g., C1-C20 alkyl, C1-C15 alkyl, C1-C10 alkyl, or C1-C3 alkyl). In embodiments, R’’ independently is an unsubstituted alkyl (e.g., unsubstituted C1-C20 alkyl, C1-C15 alkyl, C1-C10 alkyl, or C1-C3 alkyl). In embodiments, R’’ independently is unsubstituted C1-C3 alkyl. In embodiments, the aliphatic is unsubstituted. In embodiments, the aliphatic does not include any heteroatoms. Alkyl: As used herein, the term “alkyl” 10 means acyclic linear and branched hydrocarbon groups, e.g. “C1-C30alkyl” refers to alkyl groups having 1-30 carbons. An alkyl group may be linear or branched. Examples of alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, butyl, isobutyl, sec- butyl, tert-butyl, pentyl, isopentyl tert-pentylhexyl, isohexyl, etc. The term “lower alkyl" means an alkyl group straight chain or branched alkyl having 1 to 6 carbon atoms. Other 15 alkyl groups will be readily apparent to those of skill in the art given the benefit of the present disclosure. An alkyl group may be unsubstituted or substituted with one or more substituent groups as described herein. For example, an alkyl group may be substituted with one or more (e.g., 1, 2, 3, 4, 5, or 6 independently selected substituents) of halogen, -COR’’, - CO2H, -CO2R’’, -CN, -OH, -OR’’, -OCOR’, -OCO2R’’, -NH2, -NHR’’, -N(R’’)2, -SR’’ or-SO2R’’,20 wherein each instance of R’’ independently is C1-C20aliphatic (e.g., C1-C20alkyl, C1-C15alkyl, C1-C10alkyl, or C1-C3alkyl). In embodiments, R’’ independently is an unsubstituted alkyl (e.g., unsubstituted C1-C20 alkyl, C1-C15 alkyl, C1-C10 alkyl, or C1-C3 alkyl). In embodiments, R’’ independently is unsubstituted C1-C3 alkyl. In embodiments, the alkyl is substituted (e.g., with 1, 2, 3, 4, 5, or 6 substituent groups as described herein). In 25 embodiments, an alkyl group is substituted with a–OH group and may also be referred to herein as a “hydroxyalkyl” group, where the prefix denotes the –OH group and “alkyl” is as described herein.

[0051] As used herein, “alkyl” also refers to a radical of a straight-chain or branched saturated hydrocarbon group having from 1 to 50 carbon atoms (“C1-C50 alkyl”). In some 30 embodiments, an alkyl group has 1 to 40 carbon atoms (“C1-C40 alkyl”). In some embodiments, an alkyl group has 1 to 30 carbon atoms (“C1-C30 alkyl”). In some embodiments, an alkyl group has 1 to 20 carbon atoms (“C1-C20 alkyl”). In some embodiments, an alkyl group has 1 to 10 carbon atoms (“C1-C10 alkyl”). In some embodiments, an alkyl group has 1 to 9 carbon atoms (“C1-C9 alkyl”). In some embodiments, 35 an alkyl group has 1 to 8 carbon atoms (“C1-C8 alkyl”). In some embodiments, an alkyl group has 1 to 7 carbon atoms (“C1-C7 alkyl”). In some embodiments, an alkyl group has 1 to 616 carbon atoms (“C1-C6 alkyl”). In some embodiments, an alkyl group has 1 to 5 carbon atoms (“C1-C5 alkyl”). In some embodiments, an alkyl group has 1 to 4 carbon atoms (“C1-C4 alkyl”). In some embodiments, an alkyl group has 1 to 3 carbon atoms (“C1-C3 alkyl”). In some embodiments, an alkyl group has 1 to 2 carbon atoms (“C1-C2 alkyl”). In some embodiments, 5 an alkyl group has 1 carbon atom (“C1 alkyl”). In some embodiments, an alkyl group has 2 to 6 carbon atoms (“C2-C6 alkyl”). Examples of C1-C6 alkyl groups include, without limitation, methyl (C1), ethyl (C2), n-propyl (C3), isopropyl (C3), n-butyl (C4), tert-butyl (C4), sec-butyl (C4), iso-butyl (C4), n-pentyl (C5), 3-pentanyl (C5), amyl (C5), neopentyl (C5), 3-methyl-2- butanyl (C5), tertiary amyl (C5), and n-hexyl (C6). Additional examples of alkyl groups include 10 n-heptyl (C7), n-octyl (C8) and the like. Unless otherwise specified, each instance of an alkyl group is independently unsubstituted (an “unsubstituted alkyl”) or substituted (a “substituted alkyl”) with one or more substituents. In certain embodiments, the alkyl group is an unsubstituted C1-C50alkyl. In certain embodiments, the alkyl group is a substituted C1-C50alkyl. 15

[0052] Affixing the suffix “-ene” to a group indicates the group is a divalent moiety, e.g., arylene is the divalent moiety of aryl, and heteroarylene is the divalent moiety of heteroaryl.

[0053] Alkylene: The term “alkylene,” as used herein, represents a saturated divalent straight or branched chain hydrocarbon group and is exemplified by methylene, 20 ethylene, isopropylene and the like. Likewise, the term “alkenylene” as used herein represents an unsaturated divalent straight or branched chain hydrocarbon group having one or more unsaturated carbon-carbon double bonds that may occur in any stable point along the chain, and the term “alkynylene” herein represents an unsaturated divalent straight or branched chain hydrocarbon group having one or more unsaturated carbon-carbon triple 25 bonds that may occur in any stable point along the chain. In certain embodiments, an alkylene, alkenylene, or alkynylene group may comprise one or more cyclic aliphatic and / or one or more heteroatoms such as oxygen, nitrogen, or sulfur and may optionally be substituted with one or more substituents such as alkyl, halo, alkoxyl, hydroxy, amino, aryl, ether, ester or amide. For example, an alkylene, alkenylene, or alkynylene may be 30 substituted with one or more (e.g., 1, 2, 3, 4, 5, or 6 independently selected substituents) of halogen, -COR’’, -CO2H, -CO2R’’, -CN, -OH, -OR’’, -OCOR’’, -OCO2R’’, -NH2, -NHR’’, - N(R’’)2, -SR’’ or -SO2R’’, wherein each instance of R’’ independently is C1-C20 aliphatic (e.g., C1-C20 alkyl, C1-C15 alkyl, C1-C10 alkyl, or C1-C3 alkyl). In embodiments, R’’ independently is an unsubstituted alkyl (e.g., unsubstituted C1-C20 alkyl, C1-C15 alkyl, C1-C10 alkyl, or C1-C3 35 alkyl). In embodiments, R’’ independently is unsubstituted C1-C3 alkyl. In certain embodiments, an alkylene, alkenylene, or alkynylene is unsubstituted. In certain17 embodiments, an alkylene, alkenylene, or alkynylene does not include any heteroatoms. Alkenyl: As used herein, “alkenyl” means any linear or branched hydrocarbon chains having one or more unsaturated carbon-carbon double bonds that may occur in any stable point along the chain, e.g. “C2-C30 alkenyl” refers to an alkenyl group having 2-30 carbons. For 5 example, an alkenyl group includes prop-2-enyl, but-2-enyl, but-3-enyl, 2-methylprop-2-enyl, hex-2-enyl, hex-5-enyl, 2,3-dimethylbut-2-enyl, and the like. In embodiments, the alkenyl comprises 1, 2, or 3 carbon-carbon double bond. In embodiments, the alkenyl comprises a single carbon-carbon double bond. In embodiments, multiple double bonds (e.g., 2 or 3) are conjugated. An alkenyl group may be unsubstituted or substituted with one or more 10 substituent groups as described herein. For example, an alkenyl group may be substituted with one or more (e.g., 1, 2, 3, 4, 5, or 6 independently selected substituents) of halogen, - COR’’, -CO2H, -CO2R’’, -CN, -OH, -OR’’, -OCOR’’, -OCO2R’’, -NH2, -NHR’’, -N(R’’)2, -SR’’ or- SO2R’’, wherein each instance of R’’ independently is C1-C20aliphatic (e.g., C1-C20alkyl, C1- C15alkyl, C1-C10alkyl, or C1-C3alkyl). In embodiments, R’’ independently is an 15 unsubstituted alkyl (e.g., unsubstituted C1-C20alkyl, C1-C15alkyl, C1-C10alkyl, or C1-C3alkyl). In embodiments, R’’ independently is unsubstituted C1-C3alkyl. In embodiments, the alkenyl is unsubstituted. In embodiments, the alkenyl is substituted (e.g., with 1, 2, 3, 4, 5, or 6 substituent groups as described herein). In embodiments, an alkenyl group is substituted with a–OH group and may also be referred to herein as a “hydroxyalkenyl” group, where the 20 prefix denotes the –OH group and “alkenyl” is as described herein.

[0054] As used herein, “alkenyl” also refers to a radical of a straight-chain or branched hydrocarbon group having from 2 to 50 carbon atoms and one or more carbon- carbon double bonds (e.g., 1, 2, 3, or 4 double bonds) (“C2-C50 alkenyl”). In some embodiments, an alkenyl group has 2 to 40 carbon atoms (“C2-C40alkenyl”). In some 25 embodiments, an alkenyl group has 2 to 30 carbon atoms (“C2-C30 alkenyl”). In some embodiments, an alkenyl group has 2 to 20 carbon atoms (“C2-C20 alkenyl”). In some embodiments, an alkenyl group has 2 to 10 carbon atoms (“C2-C10 alkenyl”). In some embodiments, an alkenyl group has 2 to 9 carbon atoms (“C2-C9 alkenyl”). In some embodiments, an alkenyl group has 2 to 8 carbon atoms (“C2-C8 alkenyl”). In some 30 embodiments, an alkenyl group has 2 to 7 carbon atoms (“C2-C7 alkenyl”). In some embodiments, an alkenyl group has 2 to 6 carbon atoms (“C2-C6 alkenyl”). In some embodiments, an alkenyl group has 2 to 5 carbon atoms (“C2-C5 alkenyl”). In some embodiments, an alkenyl group has 2 to 4 carbon atoms (“C2-C4 alkenyl”). In some embodiments, an alkenyl group has 2 to 3 carbon atoms (“C2-C3 alkenyl”). In some 35 embodiments, an alkenyl group has 2 carbon atoms (“C2 alkenyl”). The one or more carbon- carbon double bonds can be internal (such as in 2-butenyl) or terminal (such as in 1-18 butenyl). Examples of C2-C4 alkenyl groups include, without limitation, ethenyl (C2), 1- propenyl (C3), 2-propenyl (C3), 1-butenyl (C4), 2-butenyl (C4), butadienyl (C4), and the like. Examples of C2-C6 alkenyl groups include the aforementioned C2-C4 alkenyl groups as well as pentenyl (C5), pentadienyl (C5), hexenyl (C6), and the like. Additional examples of alkenyl 5 include heptenyl (C7), octenyl (C8), octatrienyl (C8), and the like. Unless otherwise specified, each instance of an alkenyl group is independently unsubstituted (an “unsubstituted alkenyl”) or substituted (a “substituted alkenyl”) with one or more substituents. In certain embodiments, the alkenyl group is an unsubstituted C2-C50 alkenyl. In certain embodiments, the alkenyl group is a substituted C2-C50 alkenyl. 10

[0055] Alkynyl: As used herein, “alkynyl” means any hydrocarbon chain of either linear or branched configuration, having one or more carbon-carbon triple bonds occurring in any stable point along the chain, e.g., “C2-C30alkynyl”, refers to an alkynyl group having 2-30 carbons. Examples of an alkynyl group include prop-2-ynyl, but-2-ynyl, but-3-ynyl, pent-2- ynyl, 3-methylpent-4-ynyl, hex-2-ynyl, hex-5-ynyl, etc. In embodiments, an alkynyl 15 comprises one carbon-carbon triple bond. An alkynyl group may be unsubstituted or substituted with one or more substituent groups as described herein. For example, an alkynyl group may be substituted with one or more (e.g., 1, 2, 3, 4, 5, or 6 independently selected substituents) of halogen, -COR’’, -CO2H, -CO2R’’, -CN, -OH, -OR’’, -OCOR’’, - OCO2R’’, -NH2, -NHR’’, -N(R’’)2, -SR’’ or-SO2R’’, wherein each instance of R’’ independently 20 is C1-C20aliphatic (e.g., C1-C20alkyl, C1-C15alkyl, C1-C10alkyl, or C1-C3alkyl). In embodiments, R’’ independently is an unsubstituted alkyl (e.g., unsubstituted C1-C20alkyl, C1-C15 alkyl, C1-C10 alkyl, or C1-C3 alkyl). In embodiments, R’’ independently is unsubstituted C1-C3 alkyl. In embodiments, the alkynyl is unsubstituted. In embodiments, the alkynyl is substituted (e.g., with 1, 2, 3, 4, 5, or 6 substituent groups as described 25 herein).

[0056] As used herein, “alkynyl” also refers to a radical of a straight-chain or branched hydrocarbon group having from 2 to 50 carbon atoms and one or more carbon- carbon triple bonds (e.g., 1, 2, 3, or 4 triple bonds) and optionally one or more double bonds (e.g., 1, 2, 3, or 4 double bonds) (“C2-C50 alkynyl”). An alkynyl group that has one or more 30 triple bonds, and one or more double bonds is also referred to as an “ene-yne”. In some embodiments, an alkynyl group has 2 to 40 carbon atoms (“C2-C40 alkynyl”). In some embodiments, an alkynyl group has 2 to 30 carbon atoms (“C2-C30 alkynyl”). In some embodiments, an alkynyl group has 2 to 20 carbon atoms (“C2-C20 alkynyl”). In some embodiments, an alkynyl group has 2 to 10 carbon atoms (“C2-C10 alkynyl”). In some 35 embodiments, an alkynyl group has 2 to 9 carbon atoms (“C2-C9 alkynyl”). In some embodiments, an alkynyl group has 2 to 8 carbon atoms (“C2-C8 alkynyl”). In some19 embodiments, an alkynyl group has 2 to 7 carbon atoms (“C2-C7 alkynyl”). In some embodiments, an alkynyl group has 2 to 6 carbon atoms (“C2-C6 alkynyl”). In some embodiments, an alkynyl group has 2 to 5 carbon atoms (“C2-C5 alkynyl”). In some embodiments, an alkynyl group has 2 to 4 carbon atoms (“C2-C4 alkynyl”). In some 5 embodiments, an alkynyl group has 2 to 3 carbon atoms (“C2-C3 alkynyl”). In some embodiments, an alkynyl group has 2 carbon atoms (“C2 alkynyl”). The one or more carbon-- carbon triple bonds can be internal (such as in 2-butynyl) or terminal (such as in 1-butynyl). Examples of C2-C4 alkynyl groups include, without limitation, ethynyl (C2), 1-propynyl (C3), 2- propynyl (C3), 1-butynyl (C4), 2-butynyl (C4), and the like. Examples of C2-C6 alkenyl groups 10 include the aforementioned C2-C4alkynyl groups as well as pentynyl (C5), hexynyl (C6), and the like. Additional examples of alkynyl include heptynyl (C7), octynyl (C8), and the like. Unless otherwise specified, each instance of an alkynyl group is independently unsubstituted (an “unsubstituted alkynyl”) or substituted (a “substituted alkynyl”) with one or more substituents. In certain embodiments, the alkynyl group is an unsubstituted C2-C50alkynyl. 15 In certain embodiments, the alkynyl group is a substituted C2-C50alkynyl.

[0057] Aryl: The term “aryl” used alone or as part of a larger moiety as in “aralkyl,” refers to a monocyclic, bicyclic, or tricyclic carbocyclic ring system having a total of six to fourteen ring members, wherein said ring system has a single point of attachment to the rest of the molecule, at least one ring in the system is aromatic and wherein each ring in the 20 system contains 4 to 7 ring members. In embodiments, an aryl group has 6 ring carbon atoms (“C6aryl,” e.g., phenyl). In some embodiments, an aryl group has 10 ring carbon atoms (“C10 aryl,” e.g., naphthyl such as 1-naphthyl and 2-naphthyl). In some embodiments, an aryl group has 14 ring carbon atoms (“C14 aryl,” e.g., anthracyl). “Aryl” also includes ring systems wherein the aryl ring, as defined above, is fused with one or more carbocyclyl or 25 heterocyclyl groups wherein the radical or point of attachment is on the aryl ring, and in such instances, the number of carbon atoms continue to designate the number of carbon atoms in the aryl ring system. Exemplary aryls include phenyl, naphthyl, and anthracene.

[0058] As used herein, “aryl” also refers to a radical of a monocyclic or polycyclic 30 shared in a cyclic array) having 6-14 ring carbon atoms and zero heteroatoms provided in the aromatic ring system (“C6-C14 aryl”). In some embodiments, an aryl group has 6 ring carbon atoms (“C6 aryl”; e.g., phenyl). In some embodiments, an aryl group has 10 ring carbon atoms (“C10 aryl”; e.g., naphthyl such as 1-naphthyl and 2-naphthyl). In some embodiments, an aryl group has 14 ring carbon atoms (“C14 aryl”; e.g., anthracyl). “Aryl” also 35 includes ring systems wherein the aryl ring, as defined above, is fused with one or more carbocyclyl or heterocyclyl groups wherein the radical or point of attachment is on the aryl20 ring, and in such instances, the number of carbon atoms continue to designate the number of carbon atoms in the aryl ring system. Unless otherwise specified, each instance of an aryl group is independently unsubstituted (an “unsubstituted aryl”) or substituted (a “substituted aryl”) with one or more substituents. In certain embodiments, the aryl group is an 5 unsubstituted C6-C14 aryl. In certain embodiments, the aryl group is a substituted C6-C14 aryl.

[0059] Arylene: The term “arylene” as used herein refers to an aryl group that is divalent (that is, having two points of attachment to the molecule). Exemplary arylenes include phenylene (e.g., unsubstituted phenylene or substituted phenylene).

[0060] Carbocyclyl: As used herein, “carbocyclyl” or “carbocyclic” refers to a radical10 of a non-aromatic cyclic hydrocarbon group having from 3 to 10 ring carbon atoms (“C3-C10carbocyclyl”) and zero heteroatoms in the non-aromatic ring system. In some embodiments, a carbocyclyl group has 3 to 8 ring carbon atoms (“C3-C8carbocyclyl”). In some embodiments, a carbocyclyl group has 3 to 7 ring carbon atoms (“C3-C7carbocyclyl”). In some embodiments, a carbocyclyl group has 3 to 6 ring carbon atoms 15 (“C3-C6carbocyclyl”). In some embodiments, a carbocyclyl group has 4 to 6 ring carbon atoms (“C4-C6carbocyclyl”). In some embodiments, a carbocyclyl group has 5 to 6 ring carbon atoms (“C5-C6carbocyclyl”). In some embodiments, a carbocyclyl group has 5 to 10 ring carbon atoms (“C5-C10carbocyclyl”). Exemplary C3-C6carbocyclyl groups include, without limitation, cyclopropyl (C3), cyclopropenyl (C3), cyclobutyl (C4), cyclobutenyl (C4), 20 cyclopentyl (C5), cyclopentenyl (C5), cyclohexyl (C6), cyclohexenyl (C6), cyclohexadienyl (C6), and the like. Exemplary C3-C8carbocyclyl groups include, without limitation, the aforementioned C3-C6 carbocyclyl groups as well as cycloheptyl (C7), cycloheptenyl (C7), cycloheptadienyl (C7), cycloheptatrienyl (C7), cyclooctyl (C8), cyclooctenyl (C8), bicyclo[2.2.1]heptanyl (C7), bicyclo[2.2.2]octanyl (C8), and the like. Exemplary C3-C1025 carbocyclyl groups include, without limitation, the aforementioned C3-C8 carbocyclyl groups as well as cyclononyl (C9), cyclononenyl (C9), cyclodecyl (C10), cyclodecenyl (C10), octahydro-1H-indenyl (C9), decahydronaphthalenyl (C10), spiro[4.5]decanyl (C10), and the like. As the foregoing examples illustrate, in certain embodiments, the carbocyclyl group is either monocyclic (“monocyclic carbocyclyl”) or polycyclic (e.g., containing a fused, bridged 30 or spiro ring system such as a bicyclic system (“bicyclic carbocyclyl”) or tricyclic system (“tricyclic carbocyclyl”)) and can be saturated or can contain one or more carbon-carbon double or triple bonds. “Carbocyclyl” also includes ring systems wherein the carbocyclyl ring, as defined above, is fused with one or more aryl or heteroaryl groups wherein the point of attachment is on the carbocyclyl ring, and in such instances, the number of 35 carbons continue to designate the number of carbons in the carbocyclic ring system. Unless otherwise specified, each instance of a carbocyclyl group is independently21 unsubstituted (an “unsubstituted carbocyclyl”) or substituted (a “substituted carbocyclyl”) with one or more substituents. In certain embodiments, the carbocyclyl group is an unsubstituted C3-C10 carbocyclyl. In certain embodiments, the carbocyclyl group is a substituted C3-C10 carbocyclyl. 5

[0061] In some embodiments, “carbocyclyl” or “carbocyclic” is referred to as a “cycloalkyl”, i.e., a monocyclic, saturated carbocyclyl group having from 3 to 10 ring carbon atoms (“C3-C10 cycloalkyl”). In some embodiments, a cycloalkyl group has 3 to 8 ring carbon atoms (“C3-C8 cycloalkyl”). In some embodiments, a cycloalkyl group has 3 to 6 ring carbon atoms (“C3-C6, cycloalkyl”). In some embodiments, a cycloalkyl group has 4 to 10 6 ring carbon atoms (“C4-C6cycloalkyl”). In some embodiments, a cycloalkyl group has 5 to 6 ring carbon atoms (“C5-C6cycloalkyl”). In some embodiments, a cycloalkyl group has 5 to 10 ring carbon atoms (“C5-C10cycloalkyl”). Examples of C5-C6cycloalkyl groups include cyclopentyl (C5) and cyclohexyl (C5). Examples of C3-C6cycloalkyl groups include the aforementioned C5-C6cycloalkyl groups as well as cyclopropyl (C3) and cyclobutyl (C4). 15 Examples of C3-C8cycloalkyl groups include the aforementioned C3-C6cycloalkyl groups as well as cycloheptyl (C7) and cyclooctyl (C8). Unless otherwise specified, each instance of a cycloalkyl group is independently unsubstituted (an “unsubstituted cycloalkyl”) or substituted (a “substituted cycloalkyl”) with one or more substituents. In certain embodiments, the cycloalkyl group is an unsubstituted C3-C10cycloalkyl. In certain 20 embodiments, the cycloalkyl group is a substituted C3-C10cycloalkyl.

[0062] Halogen: As used herein, the term “halogen” means fluorine, chlorine, bromine, or iodine.

[0063] Heteroalkyl: The term “heteroalkyl” is meant a branched or unbranched alkyl, alkenyl, or alkynyl group having from 1 to 14 carbon atoms in addition to 1, 2, 3 or 4 25 heteroatoms independently selected from the group consisting of N, O, S, and P. Heteroalkyls include tertiary amines, secondary amines, ethers, thioethers, amides, thioamides, carbamates, thiocarbamates, hydrazones, imines, phosphodiesters, phosphoramidates, sulfonamides, and disulfides. A heteroalkyl group may optionally include monocyclic, bicyclic, or tricyclic rings, in which each ring desirably has three to six members. 30 Examples of heteroalkyls include polyethers, such as methoxymethyl and ethoxyethyl.

[0064] Heteroalkylene: The term “heteroalkylene,” as used herein, represents a divalent form of a heteroalkyl group as described herein.

[0065] Heteroaryl: The term “heteroaryl,” as used herein, is fully unsaturated heteroatom-containing ring wherein at least one ring atom is a heteroatom such as, but not 35 limited to, nitrogen and oxygen.22

[0066] As used herein, “heteroaryl” also refers to a radical of a 5-14 membered monocyclic or polycyclic (e.g., bicyclic or tricyclic) 4n+2 aromatic ring system (e.g., having 6, 1, 2, 3, or 4 ring heteroatoms) ring heteroatoms provided in the aromatic ring system, 5 wherein each heteroatom is independently selected from oxygen, sulfur, nitrogen, boron, silicon, and phosphorus (“5-14 membered heteroaryl”). In heteroaryl groups that contain one or more nitrogen atoms, the point of attachment can be a carbon or nitrogen atom, as valency permits. Heteroaryl polycyclic ring systems can include one or more heteroatoms in one or both rings. “Heteroaryl” includes ring systems wherein the heteroaryl ring, as defined 10 above, is fused with one or more carbocyclyl or heterocyclyl groups wherein the point of attachment is on the heteroaryl ring, and in such instances, the number of ring members continue to designate the number of ring members in the heteroaryl ring system. “Heteroaryl” also includes ring systems wherein the heteroaryl ring, as defined above, is fused with one or more aryl groups wherein the point of attachment is either on the aryl or heteroaryl ring, 15 and in such instances, the number of ring members designates the number of ring members in the fused polycyclic (aryl / heteroaryl) ring system. Polycyclic heteroaryl groups wherein one ring does not contain a heteroatom (e.g., indolyl, quinolinyl, carbazolyl, and the like) the point of attachment can be on either ring, i.e., either the ring bearing a heteroatom (e.g., 2- indolyl) or the ring that does not contain a heteroatom (e.g., 5-indolyl). 20

[0067] In some embodiments, a heteroaryl group is a 5-10 membered aromatic ring system having ring carbon atoms and 1 or more (e.g., 1, 2, 3, or 4) ring heteroatoms provided in the aromatic ring system, wherein each heteroatom is independently selected from oxygen, sulfur, nitrogen, boron, silicon, and phosphorus (“5-10 membered heteroaryl”). In some embodiments, a heteroaryl group is a 5-8 membered aromatic ring system having 25 ring carbon atoms and 1 or more (e.g., 1, 2, 3, or 4) ring heteroatoms provided in the aromatic ring system, wherein each heteroatom is independently selected from oxygen, sulfur, nitrogen, boron, silicon, and phosphorus (“5-8 membered heteroaryl”). In some embodiments, a heteroaryl group is a 5-6 membered aromatic ring system having ring carbon atoms and 1 or more (e.g., 1, 2, 3, or 4) ring heteroatoms provided in the aromatic 30 ring system, wherein each heteroatom is independently selected from oxygen, sulfur, nitrogen, boron, silicon, and phosphorus (“5-6 membered heteroaryl”). In some embodiments, the 5-6 membered heteroaryl has 1 or more (e.g., 1, 2, or 3) ring heteroatoms selected from oxygen, sulfur, nitrogen, boron, silicon, and phosphorus. In some embodiments, the 5-6 membered heteroaryl has 1 or 2 ring heteroatoms selected from 35 oxygen, sulfur, nitrogen, boron, silicon, and phosphorus. In some embodiments, the 5-6 membered heteroaryl has 1 ring heteroatom selected from oxygen, sulfur, nitrogen, boron,23 silicon, and phosphorus. Unless otherwise specified, each instance of a heteroaryl group is independently unsubstituted (an “unsubstituted heteroaryl”) or substituted (a “substituted heteroaryl”) with one or more substituents. In certain embodiments, the heteroaryl group is an unsubstituted 5-14 membered heteroaryl. In certain embodiments, the heteroaryl group is 5 a substituted 5-14 membered heteroaryl.

[0068] Exemplary 5-membered heteroaryl groups containing 1 heteroatom include, without limitation, pyrrolyl, furanyl and thiophenyl. Exemplary 5-membered heteroaryl groups containing 2 heteroatoms include, without limitation, imidazolyl, pyrazolyl, oxazolyl, isoxazolyl, thiazolyl, and isothiazolyl. Exemplary 5-membered heteroaryl groups containing 310 heteroatoms include, without limitation, triazolyl, oxadiazolyl, and thiadiazolyl. Exemplary 5- membered heteroaryl groups containing 4 heteroatoms include, without limitation, tetrazolyl. Exemplary 6-membered heteroaryl groups containing 1 heteroatom include, without limitation, pyridinyl. Exemplary 6-membered heteroaryl groups containing 2 heteroatoms include, without limitation, pyridazinyl, pyrimidinyl, and pyrazinyl. Exemplary 6-membered 15 heteroaryl groups containing 3 or 4 heteroatoms include, without limitation, triazinyl and tetrazinyl, respectively. Exemplary 7-membered heteroaryl groups containing 1 heteroatom include, without limitation, azepinyl, oxepinyl, and thiepinyl. Exemplary 5,6-bicyclic heteroaryl groups include, without limitation, indolyl, isoindolyl, indazolyl, benzotriazolyl, benzothiophenyl, isobenzothiophenyl, benzofuranyl, benzoisofuranyl, benzimidazolyl, 20 benzoxazolyl, benzisoxazolyl, benzoxadiazolyl, benzthiazolyl, benzisothiazolyl, benzthiadiazolyl, indolizinyl, and purinyl. Exemplary 6,6-bicyclic heteroaryl groups include, without limitation, naphthyridinyl, pteridinyl, quinolinyl, isoquinolinyl, cinnolinyl, quinoxalinyl, phthalazinyl, and quinazolinyl. Exemplary tricyclic heteroaryl groups include, without limitation, phenanthridinyl, dibenzofuranyl, carbazolyl, acridinyl, phenothiazinyl, phenoxazinyl 25 and phenazinyl.

[0069] As used herein, “heterocyclyl” or “heterocyclic” refers to a radical of a 3- to 14-membered non-aromatic ring system having ring carbon atoms and 1 or more (e.g., 1, 2, 3, or 4) ring heteroatoms, wherein each heteroatom is independently selected from oxygen, sulfur, nitrogen, boron, silicon, and phosphorus (“3-14 membered heterocyclyl”). In 30 heterocyclyl groups that contain one or more nitrogen atoms, the point of attachment can be a carbon or nitrogen atom, as valency permits. A heterocyclyl group can either be monocyclic (“monocyclic heterocyclyl”) or polycyclic (e.g., a fused, bridged or spiro ring system such as a bicyclic system (“bicyclic heterocyclyl”) or tricyclic system (“tricyclic heterocyclyl”)) and can be saturated or can contain one or more carbon-carbon double or 35 triple bonds. Heterocyclyl polycyclic ring systems can include one or more heteroatoms in one or both rings. “Heterocyclyl” also includes ring systems wherein the heterocyclyl ring, as24 defined above, is fused with one or more carbocyclyl groups wherein the point of attachment is either on the carbocyclyl or heterocyclyl ring, or ring systems wherein the heterocyclyl ring, as defined above, is fused with one or more aryl or heteroaryl groups, wherein the point of attachment is on the heterocyclyl ring, and in such instances, the number of ring members 5 continue to designate the number of ring members in the heterocyclyl ring system. Unless otherwise specified, each instance of heterocyclyl is independently unsubstituted (an “unsubstituted heterocyclyl”) or substituted (a “substituted heterocyclyl”) with one or more substituents. In certain embodiments, the heterocyclyl group is an unsubstituted 3-14 membered heterocyclyl. In certain embodiments, the heterocyclyl group is a substituted 3-14 10 membered heterocyclyl.

[0070] In some embodiments, a heterocyclyl group is a 5-10 membered non- aromatic ring system having ring carbon atoms and 1 or more (e.g., 1, 2, 3, or 4) ring heteroatoms, wherein each heteroatom is independently selected from oxygen, sulfur, nitrogen, boron, silicon, and phosphorus (“5-10 membered heterocyclyl”). In some 15 embodiments, a heterocyclyl group is a 5-8 membered non-aromatic ring system having ring carbon atoms and 1 or more (e.g., 1, 2, 3, or 4) ring heteroatoms, wherein each heteroatom is independently selected from oxygen, sulfur, nitrogen, boron, silicon, and phosphorus (“5-8 membered heterocyclyl”). In some embodiments, a heterocyclyl group is a 5-6 membered non-aromatic ring system having ring carbon atoms and 1 or more (e.g., 1, 2, 3, or 4) ring 20 heteroatoms, wherein each heteroatom is independently selected from oxygen, sulfur, nitrogen, boron, silicon, and phosphorus (“5-6 membered heterocyclyl”). In some embodiments, the 5-6 membered heterocyclyl has 1 or more (e.g., 1, 2, or 3) ring heteroatoms selected from oxygen, sulfur, nitrogen, boron, silicon, and phosphorus. In some embodiments, the 5-6 membered heterocyclyl has 1 or 2 ring heteroatoms selected from 25 oxygen, sulfur, nitrogen, boron, silicon, and phosphorus. In some embodiments, the 5-6 membered heterocyclyl has 1 ring heteroatom selected from oxygen, sulfur, nitrogen, boron, silicon, and phosphorus.

[0071] Exemplary 3-membered heterocyclyl groups containing 1 heteroatom include, without limitation, azirdinyl, oxiranyl, thiorenyl. Exemplary 4-membered heterocyclyl groups 30 containing 1 heteroatom include, without limitation, azetidinyl, oxetanyl and thietanyl. Exemplary 5-membered heterocyclyl groups containing 1 heteroatom include, without limitation. tetrahydrofuranyl, dihydrofuranyl, tetrahydrothiophenyl, dihydrothiophenyl, pyrrolidinyl, dihydropyrrolyl and pyrrolyl-2,5-dione. Exemplary 5- membered heterocyclyl groups containing 2 heteroatoms include, without limitation, dioxolanyl, oxathiolanyl and 35 dithiolanyl. Exemplary 5-membered heterocyclyl groups containing 3 heteroatoms include, without limitation, triazolinyl, oxadiazolinyl, and thiadiazolinyl. Exemplary 6-membered25 heterocyclyl groups containing 1 heteroatom include, without limitation, piperidinyl, tetrahydropyranyl, dihydropyridinyl, and thianyl. Exemplary 6-membered heterocyclyl groups containing 2 heteroatoms include, without limitation, piperazinyl, morpholinyl, dithianyl, dioxanyl. Exemplary 6-membered heterocyclyl groups containing 2 5 heteroatoms include, without limitation, triazinanyl. Exemplary 7-membered heterocyclyl groups containing 1 heteroatom include, without limitation, azepanyl, oxepanyl and thiepanyl. Exemplary 8-membered heterocyclyl groups containing 1 heteroatom include, without limitation, azocanyl, oxecanyl and thiocanyl. Exemplary bicyclic heterocyclyl groups include, without limitation, indolinyl, isoindolinyl, dihydrobenzofuranyl, dihydrobenzothienyl, 10 tetrahydrobenzothienyl, tetrahydrobenzofuranyl, tetrahydroindolyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl, decahydroquinolinyl, decahydroisoquinolinyl, octahydrochromenyl, octahydroisochromenyl, decahydronaphthyridinyl, decahydro-1,8-naphthyridinyl, octahydropyrrolo[3,2-b]pyrrole, indolinyl, phthalimidyl, naphthalimidyl, chromanyl, chromenyl, 1H-benzo[e][1,4]diazepinyl, 1,4,5,7-tetrahydropyrano[3,4-b] pyrrolyl, 5,6-dihydro-4H-furo[3,2-15 b]pyrrolyl, 6,7-dihydro-5H-furo[3,2-b]pyranyl, 5,7-dihydro-4H-thieno[2,3-c]pyranyl, 2,3-dihydro-1H- pyrrolo[2,3-b ]pyridinyl, 2,3-dihydrofuro[2,3-b]pyridinyl, 4,5,6,7-tetrahydro-1H-pyrrolo-[2,3- b]pyridinyl, 4,5,6,7-tetrahydrofuro[3,2-c]pyridinyl, 4,5,6,7-tetrahydrothieno [3,2- b]pyridinyl, 1,2,3,4-tetrahydro-1,6-naphthyridinyl, and the like.

[0072] Heterocycloalkyl: The term “heterocycloalkyl,” as used herein, is a non- 20 aromatic ring wherein at least one atom is a heteroatom such as, but not limited to, nitrogen, oxygen, sulfur, or phosphorus, and the remaining atoms are carbon. The heterocycloalkyl group can be substituted or unsubstituted.

[0073] As understood from the above, alkyl, alkenyl, alkynyl, acyl, carbocyclyl, heterocyclyl, aryl, and heteroaryl groups, as defined herein, are, in certain embodiments, 25 optionally substituted. Optionally substituted refers to a group which may be substituted or unsubstituted (e.g., “substituted” or “unsubstituted” alkyl, “substituted” or “unsubstituted” alkenyl, “substituted” or “unsubstituted” alkynyl, “substituted” or “unsubstituted” heteroalkyl, “substituted” or “unsubstituted” heteroalkenyl, “substituted” or ’unsubstituted” heteroalkynyl, “substituted” or “unsubstituted” carbocyclyl, “substituted” or “unsubstituted” heterocyclyl, 30 “substituted” or “unsubstituted” aryl or “substituted” or “unsubstituted” heteroaryl group. In general, the term “substituted” means that at least one hydrogen present on a group is replaced with a permissible substituent, e.g., a substituent which upon substitution results in a stable compound, e.g., a compound which does not spontaneously undergo transformation such as by rearrangement, cyclization, elimination, or other reaction. Unless otherwise 35 indicated, a “substituted” group has a substituent at one or more substitutable positions of the group, and when more than one position in any given structure is substituted, the26 substituent is either the same or different at each position. The term “substituted” is contemplated to include substitution with all permissible substituents of organic compounds, any of the substituents described herein that results in the formation of a stable compound. The present invention contemplates any and all such combinations in order to arrive at a 5 stable compound. For purposes of this invention, heteroatoms such as nitrogen may have hydrogen substituents and / or any suitable substituent as described herein which satisfy the valencies of the heteroatoms and results in the formation of a stable moiety.

[0074] Exemplary carbon atom substituents include, but are not limited to, halogen, -CN, -NO2, -N3, -SO2, -SO3H, -OH, -ORaa, -ON(Rbb)2, -N(Rbb)2, -N(Rbb)3+X-, -10 N(ORcc)Rbb, -SeH, -SeRaa, -SH, -SRaa, -SSRcc, -C(=O)Raa, -CO2H, -CHO, -C(ORcc)2, - CO2Raa, -OC(=O)Raa, -OCO2Raa, -C(=O)N(Rbb)2, -OC(=O)N(Rbb)2, -NRbbC(=O)Raa, - NRbbCO2Raa, -NRbbC(=O)N(Rbb)2, -C(=NRbb)Raa, -C(=NRbb)ORaa, -OC(=NRbb)Raa, - OC(=NRbb)ORaa, -C(=NRbb)N(Rbb)2, -OC(=NRbb)N(Rbb)2, -NRbbC(=NRbb)N(Rbb)2, - C(=O)NRbbSO2Raa, -NRbbSO2Raa, -SO2N(Rbb)2, -SO2Raa, -SO2ORaa, -OSO2Raa, - 15 S(=O)Raa, -OS(=O)Raa, -Si(Raa)3-OSi(Raa)3-C(=S)N(Rbb)2, -C(=O)SRaa, -C(=S)SRaa, - SC(=S)SRaa, -SC(=O)SRaa, -OC(=O)SRaa, -SC(=O)ORaa, -SC(=O)Raa, -P(=O)2Raa, - OP(=O)2Raa, -P(=O)(Raa)2, -OP(=O)(Raa)2, -OP(=O)(ORcc)2, -P(=O)2N(Rbb)2, - OP(=O)2N(Rbb)2, - P(=O)(NRbb)2, -OP(=O)(NRbb)2, -NRbbP(=O)(ORcc)2, - NRbbP(=O)(NRbb)2, -P(Rcc)2, - P(Rcc)3, -OP(Rcc)2, -OP(Rcc)3, -B(Raa)2, -B(ORcc)2, - 20 BRaa(ORcc), C1-C50alkyl, C2-C50alkenyl, C2-C50alkynyl, C3-C14carbocyclyl, 3-14 membered heterocyclyl, C6-C14aryl, and 5-14 membered heteroaryl, wherein each alkyl, alkenyl, alkynyl, carbocyclyl, heterocyclyl, aryl, and heteroaryl is independently substituted with 0, 1, 2, 3, 4, or 5 Rddgroups; or two geminal hydrogens on a carbon atom are replaced with the group =O, =S, =NN(Rbb)2, 25 =NNRbbC(=O)Raa, =NNRbbC(=O)ORaa, =NNRbbS(=O)2Raa, =NRbb, or =NORcc;

[0075] each instance of Raais, independently, selected from C1-C50 alkyl, C2-C50 alkenyl, C2-C50 alkynyl, C3-C10 carbocyclyl, 3-14 membered heterocyclyl, C6-C14 aryl, and 5- 14 membered heteroaryl, or two Raagroups are joined to form a 3-14 membered heterocyclyl or 5-14 membered heteroaryl ring, wherein each alkyl, alkenyl, alkynyl, carbocyclyl, 30 heterocyclyl, aryl, and heteroaryl is independently substituted with 0, 1, 2, 3, 4, or 5 Rddgroups;

[0076] each instance of Rbbis, independently, selected from hydrogen, -OH, -ORaa, - N(Rcc)2, -CN, -C(=O)Raa, -C(=O)N(Rcc)2, -CO2Raa, -SO2Raa, -C(=NRcc)ORaa, - C(=NRcc)N(Rcc)2, -SO2N(Rcc)2, -SO2Rcc, -SO2ORcc, -SORaa, -C(=S)N(Rcc)2, -C(=O)SRcc, -35 C(=S)SRcc, -P(=O)2Raa, -P(=O)(Raa)2, -P(=O)2N(Rcc)2, -P(=O)(NRcc)2, C1-C50 alkyl, C2-C50 alkenyl, C2-C50 alkynyl, C3-C10 carbocyclyl, 3-14 membered heterocyclyl, C6-C14 aryl, and 5-27 14 membered heteroaryl, or two Rbbgroups, together with the heteroatom to which they are attached, form a 3-14 membered heterocyclyl or 5-14 membered heteroaryl ring, wherein each alkyl, alkenyl, alkynyl, carbocyclyl, heterocyclyl, aryl, and heteroaryl is independently substituted with 0, 1, 2, 3, 4, or 5 Rddgroups; 5

[0077] each instance of Rccis, independently, selected from hydrogen, C1-C50 alkyl, C2-C50 alkenyl, C2-C50 alkynyl, C3-C10 carbocyclyl, 3-14 membered heterocyclyl, C6-C14 aryl, and 5-14 membered heteroaryl, or two Rccgroups, together with the heteroatom to which they are attached, form a 3-14 membered heterocyclyl or 5-14 membered heteroaryl ring, wherein each alkyl, alkenyl, alkynyl, carbocyclyl, heterocyclyl, aryl, and heteroaryl is 10 independently substituted with 0, 1, 2, 3, 4, or 5 Rddgroups;

[0078] each instance of Rddis, independently, selected from halogen, -CN, -NO2, - N3, - SO2H, -SO3H, -OH, -ORee, -ON(Rff)2, -N(Rff)2, -N(Rff)3+X-, -N(ORee)Rff, -SH, -SRee, - SSRee, -C(=O)Ree, -CO2H, -CO2Ree, -OC(=O)Ree, -OCO2Ree, -C(=O)N(Rff)2, - OC(=O)N(Rff)2, -NRffC(=O)Ree, -NRffCO2Ree, -NRffC(=O)N(Rff)2, -C(=NRff)ORee, - OC(=NRff)Ree, -15 OC(=NRff)ORee, -C(=NRff)N(Rff)2, -OC(=NRff)N(Rff)2, -NRffC(=NRff)N(Rff)2, -NRffSO2Ree, - SO2N(Rff)2, -SO2Ree, -SO2ORee, -OSO2Ree, -S(=O)Ree, -Si(Ree)3, -OSi(Ree)3, - C(=S)N(Rff)2, -C(=O)SRee, -C(=S)SRee, -SC(=S)SRee, -P(=O)2Ree, - P(=O)(Ree)2, - OP(=O)(Ree)2, -OP(=O)(ORee)2, C1-C50alkyl, C2-C50alkenyl, C2-C50alkynyl, C3-C10carbocyclyl, 3-10 membered heterocyclyl, C6-C10aryl, 5-10 membered heteroaryl, wherein 20 each alkyl, alkenyl, alkynyl, carbocyclyl, heterocyclyl, aryl, and heteroaryl is independently substituted with 0, 1, 2, 3, 4, or 5 Rgggroups, or two geminal Rddsubstituents can be joined to form =O or =S;

[0079] each instance of Reeis, independently, selected from C1-C50 alkyl, C2-C50 alkenyl, C2-C50alkynyl, C3-C10carbocyclyl, C6-C10aryl, 3-10 membered heterocyclyl, and 3- 25 10 membered heteroaryl, wherein each alkyl, alkenyl, alkynyl, carbocyclyl, heterocyclyl, aryl, and heteroaryl is independently substituted with 0, 1, 2, 3, 4, or 5 Rgggroups;

[0080] each instance of Rffis, independently, selected from hydrogen, C1-C50 alkyl, C2-C50 alkenyl, C2-C50 alkynyl, C3-C10 carbocyclyl, 3-10 membered heterocyclyl, C6-C10 aryl and 5-10 membered heteroaryl, or two Rffgroups, together with the heteroatom to which 30 they are attached, form a 3-14 membered heterocyclyl or 5-14 membered heteroaryl ring, wherein each alkyl, alkenyl, alkynyl, carbocyclyl, heterocyclyl, aryl, and heteroaryl is independently substituted with 0, 1, 2, 3, 4, or 5 Rgggroups; and

[0081] each instance of Rggis, independently, halogen, -CN, -NO2, -N3, -SO2H, - SO3H, -OH, -OC1-C50 alkyl, -ON(C1-C50 alkyl)2, -N(C1-C50 alkyl)2, -N(C1-C50 alkyl)3+X-, -35 NH(C1-C50 alkyl)2+X-, -NH2(C1-C50 alkyl) +X-, -NH3+X-, -N(OC1-C50 alkyl)(C1-C50 alkyl), - N(OH)(C1-C50 alkyl), -NH(OH), -SH, -SC1-C50 alkyl, -SS(C1-C50 alkyl), -C(=O)(C1-C50 alkyl), -28 CO2H, -CO2(C1-C50 alkyl), -OC(=O)(C1-C50 alkyl), -OCO2(C1-C50 alkyl), -C(=O)NH2, - C(=O)N(C1-C50 alkyl)2, -OC(=O)NH(C1-C50 alkyl), -NHC(=O)(C1-C50 alkyl), -N(C1-C50 alkyl)C(=O)(C1-C50 alkyl), -NHCO2(C1-C50 alkyl), -NHC(=O)N(C1-C50 alkyl)2, - NHC(=O)NH(C1-C50 alkyl), -NHC(=O)NH2, -C(=NH)O(C1-C50 alkyl),-OC(=NH)(C1-C50 5 alkyl), -OC(=NH)OC1-C50 alkyl, - C(=NH)N(C1-C50 alkyl)2, -C(=NH)NH(C1-C50 alkyl), - C(=NH)NH2, -OC(=NH)N(C1-C50alkyl)2, -OC(NH)NH(C1-C50 alkyl), -OC(NH)NH2, - NHC(NH)N(C1-C50 alkyl)2, -NHC(=NH)NH2, -NHSO2(C1-C50 alkyl), -SO2N(C1-C50 alkyl)2, - SO2NH(C1-C50 alkyl), - SO2NH2,-SO2(C1-C50 alkyl), -SO2O(C1-C50 alkyl), -OSO2(C1-C6 alkyl), - SO(C1-C6 alkyl), -Si(C1-C50 alkyl)3, -OSi(C1-C6 alkyl)3, -C(=S)N(C1-C50 alkyl)2, C(=S)NH(C1-10 C50alkyl), C(=S)NH2, -C(=O)S(C1-C6alkyl), -C(=S)S(C1-C6alkyl), -SC(=S)S(C1-C6alkyl), - P(=O)2(C1-C50alkyl), -P(=O)(C1-C50alkyl)2, -OP(=O)(C1-C50alkyl)2, -OP(=O)(OC1-C50alkyl)2, C1-C50alkyl, C2-C50alkenyl, C2-C50alkynyl, C3-C10carbocyclyl, C6-C10aryl, 3-10 membered heterocyclyl, 5-10 membered heteroaryl; or two geminal Rggsubstituents can be joined to form =O or =S; wherein X- is a counterion. 15

[0082] As used herein, the term “halo” or “halogen” refers to fluorine (fluoro, -F), chlorine (chloro, -Cl), bromine (bromo, -Br), or iodine (iodo, -I).

[0083] As used herein, a “counterion” is a negatively charged group associated with a positively charged quarternary amine in order to maintain electronic neutrality. Exemplary counterions include halide ions (e.g., F-, Cl-, Br-, I-), NO3-, ClO4-, OH-, H2PO4-, HSO4-, 20 sulfonate ions (e.g., methansulfonate, trifluoromethanesulfonate, p-toluenesulfonate, benzenesulfonate, 10-camphor sulfonate, naphthalene-2-sulfonate, naphthalene-l-sulfonic acid-5-sulfonate, ethan-1-sulfonic acid-2-sulfonate, and the like), and carboxylate ions (e.g., acetate, ethanoate, propanoate, benzoate, glycerate, lactate, tartrate, glycolate, and the like). 25

[0084] Nitrogen atoms can be substituted or unsubstituted as valency permits, and include primary, secondary, tertiary, and quarternary nitrogen atoms. Exemplary nitrogen atom substitutents include, but are not limited to, hydrogen, -OH, -ORaa, -N(Rcc)2, -CN, - C(=O)Raa, -C(=O)N(Rcc)2, -CO2Raa, -SO2Raa, -C(=NRbb)Raa, -C(=NRcc)ORaa, - C(=NRcc)N(Rcc)2, -SO2N(Rcc)2, -SO2Rcc, -SO2ORcc, -SORaa, -C(=S)N(Rcc)2, -C(=O)SRcc, -30 C(=S)SRcc, -P(=O)2Raa, -P(=O)(Raa)2, -P(=O)2N(Rcc)2, -P(=O)(NRcc)2, C1-C50 alkyl, C2-C50 alkenyl, C2-C50 alkynyl, C3-C10 carbocyclyl, 3-14 membered heterocyclyl, C6-C14 aryl, and 5- 14 membered heteroaryl, or two Rccgroups, together with the N atom to which they are attached, form a 3-14 membered heterocyclyl or 5-14 membered heteroaryl ring, wherein each alkyl, alkenyl, alkynyl, carbocyclyl, heterocyclyl, aryl, and heteroaryl is independently 35 substituted with 0, 1, 2, 3, 4, or 5 Rddgroups, and wherein Raa, Rbb, Rccand Rddare as defined above.29

[0085] In certain embodiments, the substituent present on a nitrogen atom is a nitrogen protecting group (also referred to as an amino protecting group). Nitrogen protecting groups are well known in the art and include those described in detail in Protecting Groups in Organic Synthesis, T. W. Greene and P. G. M. Wuts, 3rd edition, John Wiley & Sons, 1999, 5 incorporated herein by reference.

[0086] For example, nitrogen protecting groups such as amide groups (e.g., - C(=O)Raa) include, but are not limited to, formamide, acetamide, chloroacetamide, trichloroacetamide, trifluoroacetamide, phenylacetamide, 3-phenylpropanamide, picolinamide, 3-pyridylcarboxamide, N-benzoylphenylalanyl derivative, benzamide, p-10 phenylbenzamide, o-nitophenylacetamide, o-nitrophenoxyacetamide, acetoacetamide, (N’- dithiobenzyloxyacylamino)acetamide, 3-(p-hydroxyphenyl)propanamide, 3-(o- nitrophenyl)propanamide, 2-methyl-2-(o-nitrophenoxy)propanamide, 2-methyl-2-(o- phenylazophenoxy)propanamide, 4-chlorobutanamide, 3-methyl-3-nitrobutanamide, o- nitrocinnamide, N-acetylmethionine derivative, o-nitrobenzamide and o- 15 (benzoyloxymethyl)benzamide.

[0087] Nitrogen protecting groups such as carbamate groups (e.g., -C(=O)ORaa) include, but are not limited to, methyl carbamate, ethyl carbamante, 9-fluorenylmethyl carbamate (Fmoc), 9-(2-sulfo)fluorenylmethyl carbamate, 9-(2,7-dibromo)fluoroenylmethyl carbamate, 2,7-di-t-butyl-[9-(10,10-dioxo-10,10,10,10-tetrahydrothioxanthyl)]methyl 20 carbamate (DBD-Tmoc), 4-methoxyphenacyl carbamate (Phenoc), 2,2,2-trichloroethyl carbamate (Troc), 2-trimethylsilylethyl carbamate (Teoc), 2-phenylethyl carbamate (hZ), 1- (1-adamantyl)-1-methylethyl carbamate (Adpoc), 1,1-dimethyl-2-haloethyl carbamate, 1,1- dimethyl-2,2-dibromoethyl carbamate (DB-t-BOC), 1,1-dimethyl-2,2,2-trichloroethyl carbamate (TCBOC), 1-methyl-1-(4-biphenylyl)ethyl carbamate (Bpoc), 1-(3,5-di-t- 25 butylphenyl)-1-methylethyl carbamate (t-Bumeoc), 2-(2’-and 4’-pyridyl)ethyl carbamate (Pyoc), 2-(N,N-dicyclohexylcarboxamido)ethyl carbamate, t-butyl carbamate (BOC), 1- adamantyl carbamate (Adoc), vinyl carbamate (Voc), allyl carbamate (Alloc), 1-isopropylallyl carbamate (Ipaoc), cinnamyl carbamate (Coc), 4-nitrocinnamyl carbamate (Noc), 8-quinolyl carbamate, N-hydroxypiperidinyl carbamate, alkyldithio carbamate, benzyl carbamate (Cbz),30 p-methoxybenzyl carbamate (Moz), p-nitobenzyl carbamate, p-bromobenzyl carbamate, p- chlorobenzyl carbamate, 2,4-dichlorobenzyl carbamate, 4-methylsulfinylbenzyl carbamate (Msz), 9-anthrylmethyl carbamate, diphenylmethyl carbamate, 2-methylthioethyl carbamate, 2-methylsulfonylethyl carbamate, 2-(p-toluenesulfonyl)ethyl carbamate, [2-(1,3- dithianyl)]methyl carbamate (Dmoc), 4- methylthiophenyl carbamate (Mtpc), 2,4-35 dimethylthiophenyl carbamate (Bmpc), 2-phosphonioethyl carbamate (Peoc), 2- triphenylphosphonioisopropyl carbamate (Ppoc), 1,1-dimethyl-2-cyanoethyl carbamate, m-30 chloro-p-acyloxybenzyl carbamate, p-(dihydroxyboryl)benzyl carbamate, 5- benzisoxazolylmethyl carbamate, 2-(trifluoromethyl)-6-chromonylmethyl carbamate (Tcroc), m-nitrophenyl carbamate, 3,5-dimethoxybenzyl carbamate, o-nitrobenzyl carbamate, 3,4- dimethoxy-6-nitrobenzyl carbamate, phenyl(o-nitrophenyl)methyl carbamate, t-amyl 5 carbamate, S-benzyl thiocarbamate, p-cyanobenzyl carbamate, cyclobutyl carbamate, cyclohexyl carbamate, cyclopentyl carbamate, cyclopropylmethyl carbamate, p- decyloxybenzyl carbamate, 2,2-dimethoxyacylvinyl carbamate, o-(N,N- dimethylcarboxamido)benzyl carbamate, 1,1-dimethyl-3-(N,N-dimethylcarboxamido)propyl carbamate, 1,1-dimethylpropynyl carbamate, di(2-pyridyl)methyl carbamate, 2-furanylmethyl 10 carbamate, 2-iodoethyl carbamate, isoborynl carbamate, isobutyl carbamate, isonicotinyl carbamate, p-(p’-methoxyphenylazo)benzyl carbamate, 1-methylcyclobutyl carbamate, 1- methylcyclohexyl carbamate, 1-methyl-l-cyclopropylmethyl carbamate, 1-methyl-1(3,5- dimethoxyphenyl)ethyl carbamate, 1-methyl-1-(p-phenylazophenyl)ethyl carbamate, 1- methyl-l-phenylethyl carbamate, 1- methyl-1-(4-pyridyl)ethyl carbamate, phenyl carbamate,15 p-(phenylazo)benzyl carbamate, 2,4,6-tri-t-butylphenyl carbamate, 4- (trimethylammonium)benzyl carbamate, and 2,4,6-trimethylbenzyl carbamate.

[0088] Nitrogen protecting groups such as sulfonamide groups (e.g., -S(=O)2Raa) include, but are not limited to, p-toluenesulfonamide (Ts), benzenesulfonamide, 2,3,6,- trimethyl-4-methoxybenzenesulfonamide (Mtr), 2,4,6-trimethoxybenzenesulfonamide (Mtb),20 2,6-dimethyl-4-methoxybenzenesulfonamide (Pme), 2,3,5,6-tetramethyl-4- methoxybenzenesulfonamide (Mte), 4-methoxybenzenesulfonamide (Mbs), 2,4,6- trimethylbenzenesulfonamide (Mts), 2,6-dimethoxy-4-methylbenzenesulfonamide (iMds), trimethylsilylethanesulfonamide (SES), 9-anthracenesulfonamide, 4-(4’,8’- 25 dimethoxynaphthylmethyl)benzenesulfonamide (DNMBS), benzylsulfonamide, trifluoromethylsulfonamide, and phenacylsulfonamide.

[0089] Other nitrogen protecting groups include, but are not limited to, phenothiazinyl-(10)-acyl derivative, N’-p-toluenesulfonylaminoacyl derivative, N’ - phenylaminothioacyl derivative, N-benzoylphenylalanyl derivative, N-acetylmethionine30 derivative, 4,5-diphenyl-3-oxazolin-2-one, N-phthalimide, N-dithiasuccinimide (Dts), N-2,3- diphenylmaleimide, N-2,5-dimethylpyrrole, N-1,1,4,4- tetramethyldisilylazacyclopentane adduct (STABASE), 5-substituted 1,3-dimethyl-1,3,5-triazacyclohexan-2-one, 5-substituted 1,3-dibenzyl-1,3,5-triazacyclohexan-2-one, 1- substituted 3,5-dinitro-4-pyridone, N- methylamine, N-allylamine, N-[2- (trimethylsilyl)ethoxy]methylamine (SEM), N-3- 35 acetoxypropylamine, N-(1-isopropyl-4-nitro-2-oxo-3-pyroolin-3-yl)amine, quaternary ammonium salts, N-benzylamine, N-di(4-methoxyphenyl)methylamine, N-5-31 dibenzosuberylamine, N-triphenylmethylamine (Tr), N-[(4- methoxyphenyl)diphenylmethyl]amine (MMTr), N-9-phenylfluorenylamine (PhF), N-2,7 - dichloro-9-fluorenylmethyleneamine, N-ferrocenylmethylamino (Fcm), N-2- picolylamino N’- oxide, N-1,1-dimethylthiomethyleneamine, N-benzylideneamine, N-p- 5 methoxybenzylideneamine, N-diphenylmethyleneamine, N-[(2- pyridyl)mesityl]methyleneamine, N-(N’ ,N’-dimethylaminomethylene)amine, N,N’ - isopropylidenediamine, N-p-nitrobenzylideneamine, N-salicylideneamine, N-5- chlorosalicylideneamine, N-(5-chloro-2-hydroxyphenyl)phenylmethyleneamine, N- cyclohexylideneamine, N-(5,5-dimethyl-3-oxo-l-cyclohexenyl)amine, N-borane derivative, N-10 diphenylborinic acid derivative, N-[phenyl(pentaacylchromium- or tungsten)acyl]amine, N- copper chelate, N-zinc chelate, N-nitroamine, N-nitrosoamine, amine N-oxide, diphenylphosphinamide (Dpp), dimethylthiophosphinamide (Mpt), diphenylthiophosphinamide (Ppt), dialkyl phosphoramidates, dibenzyl phosphoramidate, diphenyl phosphoramidate, benzenesulfenamide, o-nitrobenzenesulfenamide (Nps), 2,4-15 dinitrobenzenesulfenamide, pentachlorobenzenesulfenamide, 2-nitro-4- methoxybenzenesulfenamide, triphenylmethylsulfenamide, and 3-nitropyridinesulfenamide (Npys).

[0090] In certain embodiments, the substituent present on an oxygen atom is an oxygen protecting group (also referred to as a hydroxyl protecting group). Oxygen protecting 20 groups are well known in the art and include those described in detail in Protecting Groups in Organic Synthesis, T. W. Greene and P. G. M. Wuts, 3rd edition, John Wiley & Sons, 1999, incorporated herein by reference.

[0091] Exemplary oxygen protecting groups include, but are not limited to, methyl, methoxylmethyl (MOM), methylthiomethyl (MTM), t-butylthiomethyl, 25 (phenyldimethylsilyl)methoxymethyl (SMOM), benzyloxymethyl (BOM), p- methoxybenzyloxymethyl (PMBM), (4-methoxyphenoxy)methyl (p-AOM), guaiacolmethyl (GUM), t-butoxymethyl, 4-pentenyloxymethyl (POM), siloxymethyl, 2-methoxyethoxymethyl (MEM), 2,2,2-trichloroethoxymethyl, bis(2-chloroethoxy)methyl, 2-(trimethylsilyl)ethoxymethyl (SEMOR), tetrahydropyranyl (THP), 3-bromotetrahydropyranyl, tetrahydrothiopyranyl, 1- 30 methoxycyclohexyl, 4- methoxytetrahydropyranyl (MTHP), 4-methoxytetrahydrothiopyranyl, 4- methoxytetrahydrothiopyranyl S,S-dioxide, 1-[(2-chloro-4-methyl)phenyl]-4- methoxypiperidin-4-yl (CTMP), 1,4-dioxan-2-yl, tetrahydrofuranyl, tetrahydrothiofuranyl, 2,3,3a,4,5,6,7,7a-octahydro-7,8,8-trimethyl-4,7-methanobenzofuran-2-yl, 1-ethoxyethyl, 1-(2- chloroethoxy)ethyl, 1-methyl-l-methoxyethyl, 1-methyl-1-benzyloxyethyl, 1-methyl-1-35 benzyloxy-2-fluoroethyl, 2,2,2-trichloroethyl, 2-trimethylsilylethyl, 2- (phenylselenyl)ethyl, t- butyl, allyl, p-chlorophenyl, p-methoxyphenyl, 2,4-dinitrophenyl, benzyl (Bn), p-32 methoxybenzyl, 3,4-dimethoxybenzyl, o-nitrobenzyl, p-nitrobenzyl, p-halobenzyl, 2,6- dichlorobenzyl, p-cyanobenzyl, p-phenylbenzyl, 2-picolyl, 4-picolyl, 3- methyl-2-picolyl N- naphthyldiphenylmethyl, p-methoxyphenyldiphenylmethyl, di(p- 5 methoxyphenyl)phenylmethyl, tri(p-methoxyphenyl)methyl, 4-(4’- bromophenacyloxyphenyl)diphenylmethyl, 4,4’,4”-tris(4,5-dichlorophthalimidophenyl)methyl, 4,4’,4”-tris(levulinoyloxyphenyl)methyl, 4,4’,4”-tris(benzoyloxyphenyl)methyl, 3-(imidazol-1- yl)bis(4’,4”-dimethoxyphenyl)methyl, 1,1-bis(4-methoxyphenyl)-1’-pyrenylmethyl, 9-anthryl, 9-(9-phenyl)xanthenyl, 9-(9-phenyl-10-oxo)anthryl, 1,3-benzodisulfuran-2-yl, benzisothiazolyl 10 S,S-dioxido, trimethylsilyl (TMS), triethylsilyl (TES), triisopropylsilyl (TIPS), dimethylisopropylsilyl (IPDMS), diethylisopropylsilyl (DEIPS), dimethylthexylsilyl, t- butyldimethylsilyl (TBDMS), t-butyldiphenylsilyl (TBDPS), tribenzylsilyl, tri-p-xylylsilyl, triphenylsilyl, diphenylmethylsilyl (DPMS), t-butylmethoxyphenylsilyl (TBMPS), formate, benzoylformate, acetate, chloroacetate, dichloroacetate, trichloroacetate, trifluoroacetate, 15 methoxyacetate, triphenylmethoxyacetate, phenoxyacetate, p-chlorophenoxyacetate, 3- phenylpropionate, 4-oxopentanoate (levulinate), 4,4-(ethylenedithio)pentanoate (levulinoyldithioacetal), pivaloate, adamantoate, crotonate, 4-methoxycrotonate, benzoate, p- phenylbenzoate, 2,4,6-trimethylbenzoate (mesitoate), alkyl methyl carbonate, 9- fluorenylmethyl carbonate (Fmoc), alkyl ethyl carbonate, alkyl 2,2,2-trichloroethyl carbonate 20 (Troc), 2-(trimethylsilyl)ethyl carbonate (TMSEC), 2-(phenylsulfonyl) ethyl carbonate (Psec), 2-(triphenylphosphonio) ethyl carbonate (Peoc), alkyl isobutyl carbonate, alkyl vinyl carbonate alkyl allyl carbonate, alkyl p-nitrophenyl carbonate, alkyl benzyl carbonate, alkyl p- methoxybenzyl carbonate, alkyl 3,4-dimethoxybenzyl carbonate, alkyl o-nitrobenzyl carbonate, alkyl p-nitrobenzyl carbonate, alkyl S-benzyl thiocarbonate, 4-ethoxy-1-napththyl25 carbonate, methyl dithiocarbonate, 2-iodobenzoate, 4-azidobutyrate, 4-nitro-4- methylpentanoate, o-(dibromomethyl)benzoate, 2-formylbenzenesulfonate, 2- (methylthiomethoxy)ethyl, 4-(methylthiomethoxy)butyrate, 2- (methylthiomethoxymethyl)benzoate, 2,6-dichloro-4-methylphenoxyacetate, 2,6-dichloro-4- (1,1,3,3-tetramethylbutyl)phenoxyacetate, 2,4-bis(1,1-dimethylpropyl)phenoxyacetate,30 chlorodiphenylacetate, isobutyrate, monosuccinoate, (E)-2-methyl-2-butenoate, o- tetramethylphosphorodiamidate, alkyl N-phenylcarbamate, borate, dimethylphosphinothioyl, alkyl 2,4-dinitrophenylsulfenate, sulfate, methanesulfonate (mesylate), benzylsulfonate, and tosylate (Ts). 35

[0092] In certain embodiments, the substituent present on a sulfur atom is a sulfur protecting group (also referred to as a thiol protecting group). Sulfur protecting groups are33 well known in the art and include those described in detail in Protecting Groups in Organic Synthesis, T. W. Greene and P. G. M. Wuts, 3rd edition, John Wiley & Sons, 1999, incorporated herein by reference.

[0093] Exemplary sulfur protecting groups include, but are not limited to, alkyl, 5 benzyl, p-methoxybenzyl, 2,4,6-trimethylbenzyl, 2,4,6-trimethoxybenzyl, o-hydroxybenzyl, p- hydroxybenzyl, o-acetoxybenzyl, p-acetoxybenzyl, p-nitrobenzyl, 4-picolyl, 2- quinolinylmethyl, 2-picolyl N-oxido, 9-anthrylmethyl, 9-fluorenylmethyl, xanthenyl, ferrocenylmethyl, diphenylmethyl, bis(4-methoxyphenyl)methyl, 5-dibenzosuberyl, triphenylmethyl, diphenyl-4-pyridylmethyl, phenyl, 2,4-dinitrophenyl, t-butyl, 1-adamantyl, 10 methoxymethyl (MOM), isobutoxymethyl, benzyloxymethyl, 2-tetrahydropyranyl, benzylthiomethyl, phenylthiomethyl, thiazolidino, acetamidomethyl, trimethylacetamidomethyl, benzamidomethyl, allyloxycarbonylaminomethyl, phenylacetamidomethyl, phthalimidomethyl, acetylmethyl, carboxymethyl, cyanomethyl, (2- nitro-1-phenyl)ethyl, 2-(2,4-dinitrophenyl)ethyl, 2-cyanoethyl, 2-(Trimethylsilyl)ethyl, 2,2-15 bis(carboethoxy)ethyl, (1-m-nitrophenyl-2-benzoyl)othyl, 2-phenylsulfonylethyl, 2-(4- methylphenylsulfonyl)-2-methylprop-2-yl, acetyl, benzoyl, trifluoroacetyl, N-[[(p- trichloroethoxycarbonyl, t-butoxycarbonyl, benzyloxycarbonyl, p-methoxybenzyloxycarbonyl, N-ethyl, N-methoxymethyl, sulfonate, sulfenylthiocarbonate, 3-nitro-2-pyridinesulfenyl 20 sulfide, oxathiolone. Compounds of the Invention

[0094] Liposomal-based vehicles are considered an attractive carrier for therapeutic 25 agents and remain subject to continued development efforts. While liposomal-based vehicles that comprise certain lipid components have shown promising results with regard to encapsulation, stability and site localization, there remains a great need for improvement of liposomal-based delivery systems. For example, a significant drawback of liposomal delivery systems relates to the construction of liposomes that have sufficient cell culture or in 30 vivo stability to reach desired target cells and / or intracellular compartments, and the ability of such liposomal delivery systems to efficiently release their encapsulated materials to such target cells.

[0095] In particular, there remains a need for improved lipid compounds that demonstrate improved pharmacokinetic properties, and which are capable of delivering 35 macromolecules, such as nucleic acids, to a wide variety of cell types and tissues with enhanced efficiency. Importantly, there also remains a particular need for novel lipid34 compounds that are characterized as having improved safety profiles and are capable of efficiently delivering encapsulated nucleic acids and polynucleotides to targeted cells, tissues and organs.

[0096] Described herein is a novel class of cationic lipid compounds for improved in 5 vivo delivery of therapeutic agents, such as nucleic acids. In particular, a cationic lipid described herein may be used, optionally with other lipids, to formulate a lipid-based nanoparticle (e.g., liposome) for encapsulating therapeutic agents, such as nucleic acids (e.g., DNA, siRNA, mRNA, microRNA) for therapeutic use, such as disease treatment and prevention (vaccine) purposes. 10

[0097] In embodiments, compounds of the invention as described herein can provide one or more desired characteristics or properties. That is, in certain embodiments, compounds of the invention as described herein can be characterized as having one or more properties that afford such compounds advantages relative to other similarly classified lipids. For example, compounds disclosed herein can allow for the control and tailoring of the 15 properties of liposomal compositions (e.g., lipid nanoparticles) of which they are a component. In particular, compounds disclosed herein can be characterized by enhanced transfection efficiencies and their ability to provoke specific biological outcomes. Such outcomes can include, for example enhanced cellular uptake, endosomal / lysosomal disruption capabilities and / or promoting the release of encapsulated materials (e.g., 20 polynucleotides) intracellularly. Additionally, the compounds disclosed herein have advantageous pharmacokinetic properties, biodistribution, and efficiency.

[0098] The present application demonstrates that the cationic lipids of the present invention are synthetically tractable from readily available starting materials.

[0099] Additionally, the cationic lipids of the present invention have cleavable groups 25 such as ester groups and amide groups. These cleavable groups (e.g. esters and amides) are contemplated to improve biodegradability and thus contribute to the lipids’ favorable safety profiles. [000100] Provided herein are compounds which are cationic lipids. For example, the cationic lipids of the present invention include compounds having a structure according to 30 Formula (I):35Formula (I), or a pharmaceutically acceptable salt thereof, wherein: 5 R1is selected from hydrogen, or optionally substituted (C1-C6)alkyl; R2is selected from -OH, -NH2, optionally substituted (C1-C6)alkyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted (C1-C3)alkylene- optionally substituted aryl, or optionally substituted (C1-C3)alkylene-optionally substituted heteroaryl; 10 b and c are integers that are each independently selected from 0, 1, 2, 3, or 4; a and d are integers that are each independently selected from 1, 2, 3, 4, 5 or 6; each Y1is independently selected from hydrogen or -OH; each R4is independently selected from hydrogen or optionally substituted (C1- C6)alkyl. 15 R3A, R3B, R3C, and R3Dare each independently selected from optionally substituted (C1-C25)alkyl, optionally substituted (C2-C25)alkenyl, or -W1-X1; each W1is independently selected from a covalent bond, optionally substituted (C1- C10)alkylene or optionally substituted (C2-C10)alkenylene; and each X1is independently selected from -(*C=O)-O-optionally substituted (C3-C25)alkyl, 20 -(*C=O)-O-optionally substituted (C3-C25)alkenyl, -*O-(C=O)-optionally substituted (C3-C25)alkyl, or -*O-(C=O)-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. [000101] In embodiments, the cationic lipids of the present invention include compounds having a structure according to Formula (I) wherein Y1= OH. In embodiments, 25 the cationic lipids of the present invention include compounds having a structure according to Formula (IA):36or a pharmaceutically acceptable salt thereof. [000102] In embodiments, the cationic lipids of the present invention include 5 compounds having a structure according to Formula (I) wherein Y1= OH, R1= methyl, and b and c = 1. In embodiments, the cationic lipids of the present invention include compounds having a structure according to Formula (I) wherein Y1= OH, R2= OH, and b and c = 1. In embodiments, the cationic lipids of the present invention include compounds having a structure according to Formula (I) wherein Y1= OH, R1= methyl, R2= OH, and b and c = 1. 10 In some embodiments, the cationic lipids of the present invention include compounds having a structure according to Formula (IA1):Formula (IA1) or a pharmaceutically acceptable salt thereof. 15 [000103] In embodiments, the cationic lipids of the present invention include compounds having a structure according to Formula (IB):37or a pharmaceutically acceptable salt thereof. [000104] In embodiments, the cationic lipids of the present invention include 5 compounds having a structure according to Formula (I) wherein Y1= OH, R1= methyl, and b and c = 1. In embodiments, the cationic lipids of the present invention include compounds having a structure according to Formula (I) wherein Y1= OH, R2= methyl, and b and c = 1. In embodiments, the cationic lipids of the present invention include compounds having a structure according to Formula (I) wherein Y1= OH, R1= methyl, R2= methyl, and b and c =101. In some embodiments, the cationic lipids of the present invention include compounds having a structure according to Formula (IB1):Formula (IB1) or a pharmaceutically acceptable salt thereof.15[000105] In embodiments, R1is hydrogen. In embodiments, R1is optionally substituted (C1-C6)alkyl. In embodiments, R1is methyl. [000106] In embodiments, R2is -OH. In embodiments, R2is -NH2. In embodiments, R2is optionally substituted (C1-C6)alkyl. In embodiments, R2is methyl. In embodiments, R2is ethyl. In embodiments, R2is isopropyl. In embodiments, R2is optionally substituted aryl. In 20 embodiments, R2is optionally substituted phenyl. In embodiments, R2is phenyl. In embodiments, R2is optionally substituted (C1-C3)alkylene-optionally substituted aryl. In embodiments, R2is optionally substituted (C1-C3)alkylene-optionally substituted phenyl. In38 embodiments, R2is optionally substituted benzyl. In embodiments, R2is benzyl. In embodiments, R2is optionally substituted heteroaryl. In embodiments, R2is optionally substituted (C1-C3)alkylene-optionally substituted heteroaryl. [000107] In embodiments, b is 0. In embodiments, b is 1. In embodiments, b is 2. In 5 embodiments, b is 3. In embodiments, b is 4. [000108] In embodiments, a is 3 or 4. In embodiments, a is 1. In embodiments, a is 2. In embodiments, a is 3. In embodiments, a is 4. In embodiments, a is 5. In embodiments, a is 6. [000109] In embodiments, c is 0. In embodiments, c is 1. In embodiments, c is 2. In 10 embodiments, c is 3. In embodiments, c is 4. [000110] In embodiments, d is 3 or 4. In embodiments, d is 1. In embodiments, d is 2. In embodiments, d is 3. In embodiments, d is 4. In embodiments, d is 5. In embodiments, d is 6. [000111] In embodiments, b and c are each 1. In embodiments, a and d are each 3 or 15 4. In embodiments, b and c are each 1 and a and d are each 3. In embodiments, b and c are each 1 and a and d are each 4. [000112] In embodiments, at least one Y1is -OH. In embodiments, at least one Y1is hydrogen. In embodiments, Y1is -OH. In embodiments, Y1is hydrogen. [000113] In embodiments, each R4is hydrogen. In embodiments, each R4is optionally 20 substituted (C1-C6)alkyl. In embodiments, each R4is methyl. [000114] In embodiments, R3Ais optionally substituted (C1-C25)alkyl. In embodiments, R3Ais optionally substituted (C5-C25)alkyl. In embodiments, R3Ais optionally substituted (C5-C20)alkyl. In embodiments, R3Ais optionally substituted (C5-C15)alkyl. In embodiments, R3Ais optionally substituted (C6-C12)alkyl. In embodiments, R3Ais optionally substituted 25 (C8-C10)alkyl. [000115] In embodiments, R3Ais optionally substituted (C2-C25)alkenyl. In embodiments, R3Ais optionally substituted (C5-C25)alkenyl. In embodiments, R3Ais optionally substituted (C5-C20)alkenyl. In embodiments, R3Ais optionally substituted (C10-C20)alkenyl. In embodiments, R3Ais optionally substituted (C15-C20)alkenyl. 30 [000116] In embodiments, R3Ais -W1-X1. In embodiments, W1is a covalent bond. In embodiments, W1is optionally substituted (C1-C10)alkylene. In embodiments, W1is optionally substituted (C1-C8)alkylene. In embodiments, W1is optionally substituted (C1-C6)alkylene. In embodiments, W1is optionally substituted (C1-C5)alkylene. In embodiments, W1is optionally substituted (C2-C10)alkenylene. In embodiments, W1is optionally substituted (C2- 35 C8)alkenylene. In embodiments, W1is optionally substituted (C2-C6)alkenylene. In embodiments, W1is optionally substituted (C2-C5)alkenylene. In embodiments, X1is -(*C=O)-39 O-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted 5 (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In 10 embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C20)alkenyl, wherein the atom 15 marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is - 20 *O-(C=O)-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a 25 covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkenyl, wherein the atom 30 marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. 35 [000117] In embodiments, R3Bis optionally substituted (C1-C25)alkyl. In embodiments, R3Bis optionally substituted (C5-C25)alkyl. In embodiments, R3Bis optionally substituted40 (C5-C20)alkyl. In embodiments, R3Bis optionally substituted (C5-C15)alkyl. In embodiments, R3Bis optionally substituted (C6-C12)alkyl. In embodiments, R3Bis optionally substituted (C8-C10)alkyl. [000118] In embodiments, R3Bis optionally substituted (C2-C25)alkenyl. In 5 embodiments, R3Bis optionally substituted (C5-C25)alkenyl. In embodiments, R3Bis optionally substituted (C5-C20)alkenyl. In embodiments, R3Bis optionally substituted (C10-C20)alkenyl. In embodiments, R3Bis optionally substituted (C15-C20)alkenyl. [000119] In embodiments, R3Bis -W1-X1. In embodiments, W1is a covalent bond. In embodiments, W1is optionally substituted (C1-C10)alkylene. In embodiments, W1is optionally 10 substituted (C1-C8)alkylene. In embodiments, W1is optionally substituted (C1-C6)alkylene. In embodiments, W1is optionally substituted (C1-C5)alkylene. In embodiments, W1is optionally substituted (C2-C10)alkenylene. In embodiments, W1is optionally substituted (C2- C8)alkenylene. In embodiments, W1is optionally substituted (C2-C6)alkenylene. In embodiments, W1is optionally substituted (C2-C5)alkenylene. In embodiments, X1is -(*C=O)-15 O-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a 20 covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkenyl, wherein the atom 25 marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In 30 embodiments, X1is -(*C=O)-O-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is - *O-(C=O)-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected 35 to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y1)-41 when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent 5 bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C10-C20)alkenyl, wherein the atom 10 marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. [000120] In embodiments, R3Cis optionally substituted (C1-C25)alkyl. In embodiments, R3Cis optionally substituted (C5-C25)alkyl. In embodiments, R3Cis optionally substituted 15 (C5-C20)alkyl. In embodiments, R3Cis optionally substituted (C5-C15)alkyl. In embodiments, R3Cis optionally substituted (C6-C12)alkyl. In embodiments, R3Cis optionally substituted (C8-C10)alkyl. [000121] In embodiments, R3Cis optionally substituted (C2-C25)alkenyl. In embodiments, R3Cis optionally substituted (C5-C25)alkenyl. In embodiments, R3Cis optionally 20 substituted (C5-C20)alkenyl. In embodiments, R3Cis optionally substituted (C10-C20)alkenyl. In embodiments, R3Cis optionally substituted (C15-C20)alkenyl. [000122] In embodiments, R3Cis -W1-X1. In embodiments, W1is a covalent bond. In embodiments, W1is optionally substituted (C1-C10)alkylene. In embodiments, W1is optionally substituted (C1-C8)alkylene. In embodiments, W1is optionally substituted (C1-C6)alkylene. In 25 embodiments, W1is optionally substituted (C1-C5)alkylene. In embodiments, W1is optionally substituted (C2-C10)alkenylene. In embodiments, W1is optionally substituted (C2- C8)alkenylene. In embodiments, W1is optionally substituted (C2-C6)alkenylene. In embodiments, W1is optionally substituted (C2-C5)alkenylene. In embodiments, X1is -(*C=O)- O-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W130 or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C18)alkyl, wherein 35 the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C25)alkenyl, wherein the atom42 marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkenyl, wherein the atom 5 marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In 10 embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is - *O-(C=O)-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- 15 when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C20)alkenyl, wherein the 20 atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In 25 embodiments, X1is -*O-(C=O)-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. [000123] In embodiments, R3Dis optionally substituted (C1-C25)alkyl. In embodiments, R3Dis optionally substituted (C5-C25)alkyl. In embodiments, R3Dis optionally substituted (C5-C20)alkyl. In embodiments, R3Dis optionally substituted (C5-C15)alkyl. In embodiments, 30 R3Dis optionally substituted (C6-C12)alkyl. In embodiments, R3Dis optionally substituted (C8-C10)alkyl. [000124] In embodiments, R3Dis optionally substituted (C2-C25)alkenyl. In embodiments, R3Dis optionally substituted (C5-C25)alkenyl. In embodiments, R3Dis optionally substituted (C5-C20)alkenyl. In embodiments, R3Dis optionally substituted (C10-C20)alkenyl. In 35 embodiments, R3Dis optionally substituted (C15-C20)alkenyl.43 [000125] In embodiments, R3Dis -W1-X1. In embodiments, W1is a covalent bond. In embodiments, W1is optionally substituted (C1-C10)alkylene. In embodiments, W1is optionally substituted (C1-C8)alkylene. In embodiments, W1is optionally substituted (C1-C6)alkylene. In embodiments, W1is optionally substituted (C1-C5)alkylene. In embodiments, W1is optionally 5 substituted (C2-C10)alkenylene. In embodiments, W1is optionally substituted (C2- C8)alkenylene. In embodiments, W1is optionally substituted (C2-C6)alkenylene. In embodiments, W1is optionally substituted (C2-C5)alkenylene. In embodiments, X1is -(*C=O)- O-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally 10 substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In 15 embodiments, X1is -(*C=O)-O-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkenyl, wherein the atom 20 marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In 25 embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is - *O-(C=O)-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- 30 when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C20)alkenyl, wherein the 35 atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkenyl, wherein the atom44 marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C10-C18)alkenyl, wherein the atom 5 marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. [000126] In embodiments, each R3A, R3B, R3Cand R3Dis independently selected from: 10 15455 (xvii) , for example wherein each R3A, R3B, R3Cand R3Dis selected from options (ii) or (iii). [000127] In embodiments, R3A, R3B, R3Cand R3Dare the same. In embodiments, R3Aand R3Care the same and R3Band R3Dare the same. In embodiments, R3Aand R3Care the same and R3Band R3Dare different. 10 [000128] The cationic lipids of the present invention also include compounds having a structure according to Formula (II):Formula (II) or a pharmaceutically acceptable salt thereof, 15 wherein: e and f are integers that are each independently selected from 1, 2, 3, 4, 5 or 6; each Y2is independently selected from hydrogen or -OH;46 R6is selected from hydrogen or optionally substituted (C1-C6)alkyl; R7is selected from optionally substituted (C1-C6)alkylene-R8or R8; R8is selected from optionally substituted aryl, optionally substituted heteroaryl. R5A, R5B, R5C, and R5Dare each independently selected from optionally substituted 5 (C1-C25)alkyl, optionally substituted (C2-C25)alkenyl, or -W1-X1; each W1is independently selected from a covalent bond, optionally substituted (C1- C10)alkylene or optionally substituted (C2-C10)alkenylene; and each X1is independently selected from -(*C=O)-O-optionally substituted (C3-C25)alkyl, -(*C=O)-O-optionally substituted (C3-C25)alkenyl, -*O-(C=O)-optionally substituted 10 (C3-C25)alkyl, or -*O-(C=O)-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. [000129] In embodiments, the cationic lipids of the present invention include compounds having a structure according to Formula (II) wherein Y2= OH. In embodiments, the cationic lipids of the present invention include compounds having a structure according 15 to Formula (IIA):Formula (IIA) or a pharmaceutically acceptable salt thereof. [000130] In embodiments, the cationic lipids of the present invention include 20 compounds having a structure according to Formula (IIA1):47Formula (IIA1) or a pharmaceutically acceptable salt thereof. [000131] In embodiments, the cationic lipids of the present invention include 5 compounds having a structure according to Formula (II) wherein Y2= H. In embodiments, the cationic lipids of the present invention include compounds having a structure according to Formula (IIB):Formula (IIB) 10 or a pharmaceutically acceptable salt thereof. [000132] In embodiments, e is 3 or 4. In embodiments, e is 1. In embodiments, e is 2. In embodiments, e is 3. In embodiments, e is 4. In embodiments, e is 5. In embodiments, e is 6. [000133] In embodiments, f is 3 or 4. In embodiments, f is 1. In embodiments, f is 2. In 15 embodiments, f is 3. In embodiments, f is 4. In embodiments, f is 5. In embodiments, f is 6. [000134] In embodiments e and f are each 3 or 4. In embodiments e and f are each 3. In embodiments e and f are each 4. [000135] In embodiments, at least one Y2is -OH. In embodiments, at least one Y2is hydrogen. In embodiments, Y2is -OH. In embodiments, Y2is hydrogen.48 [000136] In embodiments, each R6is hydrogen. In embodiments, each R6is optionally substituted (C1-C6)alkyl. In embodiments, each R6is methyl. [000137] In embodiments, R7is optionally substituted (C1-C6)-alkylene-R8. In embodiments, R7is R8. In embodiments, R8is optionally substituted aryl. In embodiments, 5 R8is optionally substituted heteroaryl. [000138] In embodiments, R7is –(CH2)-optionally substituted aryl. In embodiments, R7is -(CH2)2-optionally substituted aryl. In embodiments, R7is -(CH2)3-optionally substituted aryl. In embodiments, R7is –(CH2)4-optionally substituted aryl. In embodiments, R7is – (CH2)-optionally substituted heteroaryl. In embodiments, R7is -(CH2)2-optionally substituted 10 heteroaryl. [000139] In embodiments, R7is –(CH2)-optionally substituted phenyl. In embodiments, R7is -(CH2)2-optionally substituted phenyl. In embodiments, R7is -(CH2)3-optionally substituted phenyl. In embodiments, R7is –(CH2)4-optionally substituted phenyl. In embodiments, R7is –(CH2)-optionally substituted imidazolyl. In embodiments, R7is -(CH2)2- 15 optionally substituted imidazolyl. In embodiments,. embodiments,. embodiments, R7is. In embodiments, R7is49[000140] In embodiments, R7is –(CH2)-optionally substituted phenyl. In embodiments, R7is -(CH2)2-optionally substituted phenyl. In embodiments, R7is -(CH2)3-optionally 5 substituted phenyl. In embodiments, R7is –(CH2)4-optionally substituted phenyl. In embodiments, R7is –(CH2)-optionally substituted imidazolyl. In embodiments, R7is -(CH2)2- optionally substituted imidazolyl. In embodiments, R7is –(CH2)-optionally substituted indolyl. In embodiments, R7is -(CH2)2-optionally substituted indolyl. In embodiments, R7is -(CH2)3- optionally substituted indolyl. In embodiments,. embodiments, 10, . ,50 5. , . [000141] In embodiments, R5Ais optionally substituted (C1-C25)alkyl. In embodiments, R5Ais optionally substituted (C5-C25)alkyl. In embodiments, R5Ais optionally substituted (C5-C20)alkyl. In embodiments, R5Ais optionally substituted (C5-C15)alkyl. In embodiments, R5Ais optionally substituted (C6-C12)alkyl. In embodiments, R5Ais optionally substituted 10 (C8-C10)alkyl.51 [000142] In embodiments, R5Ais optionally substituted (C2-C25)alkenyl. In embodiments, R5Ais optionally substituted (C5-C25)alkenyl. In embodiments, R5Ais optionally substituted (C5-C20)alkenyl. In embodiments, R5Ais optionally substituted (C10-C20)alkenyl. In embodiments, R5Ais optionally substituted (C15-C20)alkenyl. 5 [000143] In embodiments, R5Ais -W1-X1. In embodiments, W1is a covalent bond. In embodiments, W1is optionally substituted (C1-C10)alkylene. In embodiments, W1is optionally substituted (C1-C8)alkylene. In embodiments, W1is optionally substituted (C1-C6)alkylene. In embodiments, W1is optionally substituted (C1-C5)alkylene. In embodiments, W1is optionally substituted (C2-C10)alkenylene. In embodiments, W1is optionally substituted (C2- 10 C8)alkenylene. In embodiments, W1is optionally substituted (C2-C6)alkenylene. In embodiments, W1is optionally substituted (C2-C5)alkenylene. In embodiments, X1is -(*C=O)- O-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- 15 when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C25)alkenyl, wherein the atom 20 marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In 25 embodiments, X1is -(*C=O)-O-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkyl, wherein the atom marked30 with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is - *O-(C=O)-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted 35 (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkenyl,52 wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkenyl, wherein the atom 5 marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. 10 [000144] In embodiments, R5Bis optionally substituted (C1-C25)alkyl. In embodiments, R5Bis optionally substituted (C5-C25)alkyl. In embodiments, R5Bis optionally substituted (C5-C20)alkyl. In embodiments, R5Bis optionally substituted (C5-C15)alkyl. In embodiments, R5Bis optionally substituted (C6-C12)alkyl. In embodiments, R5Bis optionally substituted (C8-C10)alkyl. 15 [000145] In embodiments, R5Bis optionally substituted (C2-C25)alkenyl. In embodiments, R5Bis optionally substituted (C5-C25)alkenyl. In embodiments, R5Bis optionally substituted (C5-C20)alkenyl. In embodiments, R5Bis optionally substituted (C10-C20)alkenyl. In embodiments, R5Bis optionally substituted (C15-C20)alkenyl. [000146] In embodiments, R5Bis -W1-X1. In embodiments, W1is a covalent bond. In 20 embodiments, W1is optionally substituted (C1-C10)alkylene. In embodiments, W1is optionally substituted (C1-C8)alkylene. In embodiments, W1is optionally substituted (C1-C6)alkylene. In embodiments, W1is optionally substituted (C1-C5)alkylene. In embodiments, W1is optionally substituted (C2-C10)alkenylene. In embodiments, W1is optionally substituted (C2- C8)alkenylene. In embodiments, W1is optionally substituted (C2-C6)alkenylene. In 25 embodiments, W1is optionally substituted (C2-C5)alkenylene. In embodiments, X1is -(*C=O)- O-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted 30 (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In 35 embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In53 embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In 5 embodiments, X1is -(*C=O)-O-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is - *O-(C=O)-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected 10 to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkenyl, 15 wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In 20 embodiments, X1is -*O-(C=O)-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. [000147] In embodiments, R5Cis optionally substituted (C1-C25)alkyl. In embodiments, 25 R5Cis optionally substituted (C5-C25)alkyl. In embodiments, R5Cis optionally substituted (C5-C20)alkyl. In embodiments, R5Cis optionally substituted (C5-C15)alkyl. In embodiments, R5Cis optionally substituted (C6-C12)alkyl. In embodiments, R5Cis optionally substituted (C8-C10)alkyl. [000148] In embodiments, R5Cis optionally substituted (C2-C25)alkenyl. In 30 embodiments, R5Cis optionally substituted (C5-C25)alkenyl. In embodiments, R5Cis optionally substituted (C5-C20)alkenyl. In embodiments, R5Cis optionally substituted (C10-C20)alkenyl. In embodiments, R5Cis optionally substituted (C15-C20)alkenyl. [000149] In embodiments, R5Cis -W1-X1. In embodiments, W1is a covalent bond. In embodiments, W1is optionally substituted (C1-C10)alkylene. In embodiments, W1is optionally 35 substituted (C1-C8)alkylene. In embodiments, W1is optionally substituted (C1-C6)alkylene. In embodiments, W1is optionally substituted (C1-C5)alkylene. In embodiments, W1is optionally54 substituted (C2-C10)alkenylene. In embodiments, W1is optionally substituted (C2- C8)alkenylene. In embodiments, W1is optionally substituted (C2-C6)alkenylene. In embodiments, W1is optionally substituted (C2-C5)alkenylene. In embodiments, X1is -(*C=O)- O-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W15or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C18)alkyl, wherein 10 the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In 15 embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C18)alkenyl, wherein the atom 20 marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is - *O-(C=O)-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally 25 substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent 30 bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C10-C20)alkenyl, wherein the atom 35 marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In55 embodiments, X1is -*O-(C=O)-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. [000150] In embodiments, R5Dis optionally substituted (C1-C25)alkyl. In embodiments, R5Dis optionally substituted (C5-C25)alkyl. In embodiments, R5Dis optionally substituted 5 (C5-C20)alkyl. In embodiments, R5Dis optionally substituted (C5-C15)alkyl. In embodiments, R5Dis optionally substituted (C6-C12)alkyl. In embodiments, R5Dis optionally substituted (C8-C10)alkyl. [000151] In embodiments, R5Dis optionally substituted (C2-C25)alkenyl. In embodiments, R5Dis optionally substituted (C5-C25)alkenyl. In embodiments, R5Dis optionally 10 substituted (C5-C20)alkenyl. In embodiments, R5Dis optionally substituted (C10-C20)alkenyl. In embodiments, R5Dis optionally substituted (C15-C20)alkenyl. [000152] In embodiments, R5Dis -W1-X1. In embodiments, W1is a covalent bond. In embodiments, W1is optionally substituted (C1-C10)alkylene. In embodiments, W1is optionally substituted (C1-C8)alkylene. In embodiments, W1is optionally substituted (C1-C6)alkylene. In 15 embodiments, W1is optionally substituted (C1-C5)alkylene. In embodiments, W1is optionally substituted (C2-C10)alkenylene. In embodiments, W1is optionally substituted (C2- C8)alkenylene. In embodiments, W1is optionally substituted (C2-C6)alkenylene. In embodiments, W1is optionally substituted (C2-C5)alkenylene. In embodiments, X1is -(*C=O)- O-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W120 or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C18)alkyl, wherein 25 the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In 30 embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C18)alkenyl, wherein the atom 35 marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkyl, wherein the atom marked56 with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is - *O-(C=O)-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- 5 when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C20)alkenyl, wherein the 10 atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. In 15 embodiments, X1is -*O-(C=O)-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond. [000153] In embodiments, each R5A, R5B, R5Cand R5Dis independently selected from: 20 2557 5, for example wherein each 10 R5A, R5B, R5Cand R5Dis option (iii). [000154] In embodiments, R5A, R5B, R5Cand R5Dare the same. In embodiments, R5Aand R5Care the same and R5Band R5Dare the same. In embodiments, R5Aand R5Care the same and R5Band R5Dare different. [000155] The cationic lipids of the present invention also include compounds having a 15 structure according to Formula (III):58Formula (III) or a pharmaceutically acceptable salt thereof, wherein: 5 h and i are integers that are each independently selected from 1, 2, 3 or 4; g and j are integers that are each independently selected from 1, 2, 3, 4, 5 or 6; k is an integer selected from 1, 2, 3, 4, 5, or 6; m is an integer selected from 0, 1, 2, 3, 4, 5, or 6; each Y3is independently selected from hydrogen or -OH; 10 X2is selected from H, NH2 and F; R10is selected from an optionally substituted aryl, optionally substituted heteroaryl, optionally substituted (C1-C25)alkyl or optionally substituted (C2-C25)alkenyl; R9A, R9B, R9C, and R9Dare each independently selected from optionally substituted (C1-C25)alkyl, optionally substituted (C2-C25)alkenyl, or -W1-X1; 15 each W1is independently selected from a covalent bond, optionally substituted (C1- C10)alkylene or optionally substituted (C2-C10)alkenylene; and each X1is independently selected from -(*C=O)-O-optionally substituted (C3-C25)alkyl, -(*C=O)-O-optionally substituted (C3-C25)alkenyl, -*O-(C=O)-optionally substituted (C3-C25)alkyl, or -*O-(C=O)-optionally substituted (C3-C25)alkenyl, wherein the atom marked 20 with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. [000156] In embodiments, the cationic lipids of the present invention include compounds of Formula (III) wherein Y3= OH. In embodiments, the cationic lipids of the present invention include compounds having a structure according to Formula (IIIA):59Formula (IIIA) or a pharmaceutically acceptable salt thereof. [000157] In embodiments, the cationic lipids of the present invention include 5 compounds having a structure according to Formula (III) wherein Y3= OH and h and i = 1. In embodiments, the cationic lipids of the present invention include compounds having a structure according to Formula (III) wherein Y3= OH and k = 2. In embodiments, the cationic lipids of the present invention include compounds having a structure according to Formula (III) wherein Y3= OH, h and i = 1 and k = 2. In embodiments, the cationic lipids of the 10 present invention include compounds having a structure according to Formula (IIIA1):60Formula (IIIA1) or a pharmaceutically acceptable salt thereof. [000158] In embodiments, the cationic lipids of the present invention include5compounds having a structure according to Formula (IIIA1i):Formula (IIIA1i) or a pharmaceutically acceptable salt thereof.61 [000159] In embodiments, h is 1 or 2. In embodiments, h is 1. In embodiments, h is 2. In embodiments, h is 3. In embodiments, h is 4. [000160] In embodiments, g is 2, 3 or 4. In embodiments, g is 3 or 4. In embodiments, g is 3. In embodiments, g is 4. In embodiments, g is 1. In embodiments, g is 2. In 5 embodiments, g is 5. In embodiments, g is 6. [000161] In embodiments, i is 1 or 2. In embodiments, i is 1. In embodiments, i is 2. In embodiments, i is 3. In embodiments, i is 4. [000162] In embodiments, j is 2, 3 or 4. In embodiments, j is 3 or 4. In embodiments, j is 3. In embodiments, j is 4. In embodiments, j is 1. In embodiments, j is 2. In embodiments, j 10 is 5. In embodiments, j is 6. [000163] In embodiments, k is 1, 2 or 3. In embodiments, k is 2. In embodiments, k is 1. In embodiments, k is 3. In embodiments, k is 4. In embodiments, k is 5. In embodiments, k is 6. [000164] In embodiments, m is 0, 1 or 2. In embodiments, m is 1. In embodiments, m is 15 0. In embodiments, m is 2. In embodiments, m is 3. In embodiments, m is 4. In embodiments, m is 5. In embodiments, m is 6. [000165] In embodiments, g and j are each 3. In embodiments, h and i are each 1. In embodiments, g and j are each 3 and h and i are each 1. In embodiments, h and i are each 1. In embodiments, g and j are each 3 and h and i are each 1, and k is 2. In embodiments, h 20 and i are each 1. In embodiments, g and j are each 3 and h and i are each 1, k is 2 and , is 1. [000166] In embodiments, at least one Y3is -OH. In embodiments, at least one Y3is hydrogen. In embodiments, Y3is -OH. In embodiments, Y3is hydrogen. [000167] In embodiments, X2is hydrogen. In embodiments, X2is NH2. In embodiments, 25 X2is F. In embodiments, X2is selected from NH2 and F. [000168] In embodiments, R10is optionally substituted aryl. In embodiments, R10is optionally substituted heteroaryl. In embodiments, R10is selected from an optionally substituted aryl or optionally substituted heteroaryl. In embodiments, R10is optionally substituted alkyl. In embodiments, R10is optionally substituted alkenyl. 30 [000169] In embodiments, R10is optionally substituted phenyl. In embodiments, R10is optionally substituted imidazolyl. In embodiments, R10is optionally substituted indolyl. In embodiments,. embodiments,.62[000170] In embodiments, R9Ais optionally substituted (C1-C25)alkyl. In embodiments, R9Ais optionally substituted (C5-C25)alkyl. In embodiments, R9Ais optionally substituted 5 (C5-C20)alkyl. In embodiments, R9Ais optionally substituted (C5-C15)alkyl. In embodiments, R9Ais optionally substituted (C6-C12)alkyl. [000171] In embodiments, R9Ais optionally substituted (C2-C25)alkenyl. In embodiments, R9Ais optionally substituted (C5-C25)alkenyl. In embodiments, R9Ais optionally substituted (C5-C20)alkenyl. In embodiments, R9Ais optionally substituted (C10-C20)alkenyl. In 10 embodiments, R9Ais optionally substituted (C15-C20)alkenyl. [000172] In embodiments, R9Ais -W1-X1. In embodiments, W1is a covalent bond. In embodiments, W1is optionally substituted (C1-C10)alkylene. In embodiments, W1is optionally substituted (C1-C8)alkylene. In embodiments, W1is optionally substituted (C1-C6)alkylene. In embodiments, W1is optionally substituted (C1-C5)alkylene. In embodiments, W1is optionally15 substituted (C2-C10)alkenylene. In embodiments, W1is optionally substituted (C2- C8)alkenylene. In embodiments, W1is optionally substituted (C2-C6)alkenylene. In embodiments, W1is optionally substituted (C2-C5)alkenylene. In embodiments, X1is -(*C=O)- O-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally 20 substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In 25 embodiments, X1is -(*C=O)-O-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In63 embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In 5 embodiments, X1is -(*C=O)-O-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is - *O-(C=O)-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected 10 to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkenyl, 15 wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In 20 embodiments, X1is -*O-(C=O)-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. [000173] In embodiments, R9Bis optionally substituted (C1-C25)alkyl. In embodiments, 25 R9Bis optionally substituted (C5-C25)alkyl. In embodiments, R9Bis optionally substituted (C5-C20)alkyl. In embodiments, R9Bis optionally substituted (C5-C15)alkyl. In embodiments, R9Bis optionally substituted (C6-C12)alkyl. [000174] In embodiments, R9Bis optionally substituted (C2-C25)alkenyl. In embodiments, R9Bis optionally substituted (C5-C25)alkenyl. In embodiments, R9Bis optionally 30 substituted (C5-C20)alkenyl. In embodiments, R9Bis optionally substituted (C10-C20)alkenyl. In embodiments, R9Bis optionally substituted (C15-C20)alkenyl. [000175] In embodiments, R9Bis -W1-X1. In embodiments, W1is a covalent bond. In embodiments, W1is optionally substituted (C1-C10)alkylene. In embodiments, W1is optionally substituted (C1-C8)alkylene. In embodiments, W1is optionally substituted (C1-C6)alkylene. In 35 embodiments, W1is optionally substituted (C1-C5)alkylene. In embodiments, W1is optionally substituted (C2-C10)alkenylene. In embodiments, W1is optionally substituted (C2-64 C8)alkenylene. In embodiments, W1is optionally substituted (C2-C6)alkenylene. In embodiments, W1is optionally substituted (C2-C5)alkenylene. In embodiments, X1is -(*C=O)- O-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally 5 substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In 10 embodiments, X1is -(*C=O)-O-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkenyl, wherein the atom 15 marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In 20 embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is - *O-(C=O)-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- 25 when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C20)alkenyl, wherein the 30 atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In 35 embodiments, X1is -*O-(C=O)-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond.65 [000176] In embodiments, R9Cis optionally substituted (C1-C25)alkyl. In embodiments, R9Cis optionally substituted (C5-C25)alkyl. In embodiments, R9Cis optionally substituted (C5-C20)alkyl. In embodiments, R9Cis optionally substituted (C5-C15)alkyl. In embodiments, R9Cis optionally substituted (C6-C12)alkyl. 5 [000177] In embodiments, R9Cis optionally substituted (C2-C25)alkenyl. In embodiments, R9Cis optionally substituted (C5-C25)alkenyl. In embodiments, R9Cis optionally substituted (C5-C20)alkenyl. In embodiments, R9Cis optionally substituted (C10-C20)alkenyl. In embodiments, R9Cis optionally substituted (C15-C20)alkenyl. [000178] In embodiments, R9Cis -W1-X1. In embodiments, W1is a covalent bond. In 10 embodiments, W1is optionally substituted (C1-C10)alkylene. In embodiments, W1is optionally substituted (C1-C8)alkylene. In embodiments, W1is optionally substituted (C1-C6)alkylene. In embodiments, W1is optionally substituted (C1-C5)alkylene. In embodiments, W1is optionally substituted (C2-C10)alkenylene. In embodiments, W1is optionally substituted (C2- C8)alkenylene. In embodiments, W1is optionally substituted (C2-C6)alkenylene. In 15 embodiments, W1is optionally substituted (C2-C5)alkenylene. In embodiments, X1is -(*C=O)- O-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted 20 (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In 25 embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C20)alkenyl, wherein the atom 30 marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is - 35 *O-(C=O)-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally66 substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkenyl, 5 wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In 10 embodiments, X1is -*O-(C=O)-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. [000179] In embodiments, R9Dis optionally substituted (C1-C25)alkyl. In embodiments, 15 R9Dis optionally substituted (C5-C25)alkyl. In embodiments, R9Dis optionally substituted (C5-C20)alkyl. In embodiments, R9Dis optionally substituted (C5-C15)alkyl. In embodiments, R9Dis optionally substituted (C6-C12)alkyl. [000180] In embodiments, R9Dis optionally substituted (C2-C25)alkenyl. In embodiments, R9Dis optionally substituted (C5-C25)alkenyl. In embodiments, R9Dis optionally 20 substituted (C5-C20)alkenyl. In embodiments, R9Dis optionally substituted (C10-C20)alkenyl. In embodiments, R9Dis optionally substituted (C15-C20)alkenyl. [000181] In embodiments, R9Dis -W1-X1. In embodiments, W1is a covalent bond. In embodiments, W1is optionally substituted (C1-C10)alkylene. In embodiments, W1is optionally substituted (C1-C8)alkylene. In embodiments, W1is optionally substituted (C1-C6)alkylene. In 25 embodiments, W1is optionally substituted (C1-C5)alkylene. In embodiments, W1is optionally substituted (C2-C10)alkenylene. In embodiments, W1is optionally substituted (C2- C8)alkenylene. In embodiments, W1is optionally substituted (C2-C6)alkenylene. In embodiments, W1is optionally substituted (C2-C5)alkenylene. In embodiments, X1is -(*C=O)- O-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W130 or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C18)alkyl, wherein 35 the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C25)alkenyl, wherein the atom67 marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkenyl, wherein the atom 5 marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In 10 embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is - *O-(C=O)-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- 15 when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C20)alkenyl, wherein the 20 atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. In 25 embodiments, X1is -*O-(C=O)-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y3)- when W1is a covalent bond. [000182] In embodiments, each R9A, R9B, R9Cand R9Dis independently selected from: 30,68 5 10, for example wherein each R9A, R9B, R9Cand R9Dis option (iii).69 [000183] In embodiments, R9A, R9B, R9Cand R9Dare the same. In embodiments, R9Aand R9Bare the same and R9Cand R9Dare the same. In embodiments, R9Aand R9Care the same and R9Band R9Dare the same. In embodiments, R9Aand R9Care the same and R9Band R9Dare different. 5 [000184] The cationic lipids of the present invention also include compounds having a structure according to Formula (IV):Formula (IV) wherein:10p and q are integers that are each independently selected from 1, 2, 3, 4, 5 or 6; each Y4is independently selected from hydrogen or -OH; R11is selected from hydrogen or optionally substituted (C1-C6)alkyl; X3is selected from a covalent bond, -O-, or -N(R13)-; R13is selected from hydrogen or optionally substituted (C1-C6)alkyl;15R12A, R12B, R12C, and R12Dare each independently selected from optionally substituted (C1-C25)alkyl, optionally substituted (C2-C25)alkenyl, or -W1-X1; each W1is independently selected from a covalent bond, optionally substituted (C1- C10)alkylene or optionally substituted (C2-C10)alkenylene; and each X1is independently selected from -(*C=O)-O-optionally substituted (C3-C25)alkyl, 20 -(*C=O)-O-optionally substituted (C3-C25)alkenyl, -*O-(C=O)-optionally substituted (C3-C25)alkyl, or -*O-(C=O)-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. [000185] In embodiments, the cationic lipids of the present invention include compounds having a structure according to Formula (IV) wherein Y4= OH. In embodiments, 25 the cationic lipids of the present invention include compounds having a structure according to Formula (IVA):70Formula (IVA) or a pharmaceutically acceptable salt thereof. [000186] In embodiments, p is 3. In embodiments, p is 1. In embodiments, p is 2. In 5 embodiments, p is 4. In embodiments, p is 5. In embodiments, p is 6. [000187] In embodiments, q is 3. In embodiments, q is 1. In embodiments, q is 2. In embodiments, q is 4. In embodiments, q is 5. In embodiments, q is 6. [000188] In embodiments p and q are each 3. [000189] In embodiments, at least one Y4is -OH. In embodiments, at least one Y4is10hydrogen. In embodiments, Y4is -OH. In embodiments, Y4is hydrogen. [000190] In embodiments, R11is hydrogen. In embodiments, In embodiments, R11is optionally substituted (C1-C6)alkyl. In embodiments, R11is methyl. [000191] In embodiments, X3is a covalent bond. In embodiments, X3is -O-. In embodiments, X3is -N(R13)-. In embodiments, X3is -N(H)-. 15 [000192] In embodiments, R13is hydrogen. [000193] In embodiments, R12Ais optionally substituted (C1-C25)alkyl. In embodiments, R12Ais optionally substituted (C5-C25)alkyl. In embodiments, R12Ais optionally substituted (C5-C20)alkyl. In embodiments, R12Ais optionally substituted (C5-C15)alkyl. In embodiments, R12Ais optionally substituted (C6-C12)alkyl. In embodiments, R12Ais optionally substituted 20 (C8-C10)alkyl. [000194] In embodiments, R12Ais optionally substituted (C2-C25)alkenyl. In embodiments, R12Ais optionally substituted (C5-C25)alkenyl. In embodiments, R12Ais optionally substituted (C5-C20)alkenyl. In embodiments, R12Ais optionally substituted (C10- C20)alkenyl. In embodiments, R12Ais optionally substituted (C15-C20)alkenyl. 25 [000195] In embodiments, R12Ais -W1-X1. In embodiments, W1is a covalent bond. In embodiments, W1is optionally substituted (C1-C10)alkylene. In embodiments, W1is optionally substituted (C1-C8)alkylene. In embodiments, W1is optionally substituted (C1-C6)alkylene. In embodiments, W1is optionally substituted (C1-C5)alkylene. In embodiments, W1is optionally71 substituted (C2-C10)alkenylene. In embodiments, W1is optionally substituted (C2- C8)alkenylene. In embodiments, W1is optionally substituted (C2-C6)alkenylene. In embodiments, W1is optionally substituted (C2-C5)alkenylene. In embodiments, X1is -(*C=O)- O-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W15or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C18)alkyl, wherein 10 the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In 15 embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C18)alkenyl, wherein the atom 20 marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is - *O-(C=O)-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally 25 substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent 30 bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C10-C20)alkenyl, wherein the atom 35 marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In72 embodiments, X1is -*O-(C=O)-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. [000196] In embodiments, R12Bis optionally substituted (C1-C25)alkyl. In embodiments, R12Bis optionally substituted (C5-C25)alkyl. In embodiments, R12Bis optionally substituted 5 (C5-C20)alkyl. In embodiments, R12Bis optionally substituted (C5-C15)alkyl. In embodiments, R12Bis optionally substituted (C6-C12)alkyl. In embodiments, R12Bis optionally substituted (C8-C10)alkyl. [000197] In embodiments, R12Bis optionally substituted (C2-C25)alkenyl. In embodiments, R12Bis optionally substituted (C5-C25)alkenyl. In embodiments, R12Bis 10 optionally substituted (C5-C20)alkenyl. In embodiments, R12Bis optionally substituted (C10- C20)alkenyl. In embodiments, R12Bis optionally substituted (C15-C20)alkenyl. [000198] In embodiments, R12Bis -W1-X1. In embodiments, W1is a covalent bond. In embodiments, W1is optionally substituted (C1-C10)alkylene. In embodiments, W1is optionally substituted (C1-C8)alkylene. In embodiments, W1is optionally substituted (C1-C6)alkylene. In 15 embodiments, W1is optionally substituted (C1-C5)alkylene. In embodiments, W1is optionally substituted (C2-C10)alkenylene. In embodiments, W1is optionally substituted (C2- C8)alkenylene. In embodiments, W1is optionally substituted (C2-C6)alkenylene. In embodiments, W1is optionally substituted (C2-C5)alkenylene. In embodiments, X1is -(*C=O)- O-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W120 or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C18)alkyl, wherein 25 the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In 30 embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C18)alkenyl, wherein the atom 35 marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkyl, wherein the atom marked73 with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is - *O-(C=O)-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- 5 when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C20)alkenyl, wherein the 10 atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In 15 embodiments, X1is -*O-(C=O)-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. [000199] In embodiments, R12Cis optionally substituted (C1-C25)alkyl. In embodiments, R12Cis optionally substituted (C5-C25)alkyl. In embodiments, R12Cis optionally substituted (C5-C20)alkyl. In embodiments, R12Cis optionally substituted (C5-C15)alkyl. In embodiments, 20 R12Cis optionally substituted (C6-C12)alkyl. In embodiments, R12Cis optionally substituted (C8-C10)alkyl. [000200] In embodiments, R12Cis optionally substituted (C2-C25)alkenyl. In embodiments, R12Cis optionally substituted (C5-C25)alkenyl. In embodiments, R12Cis optionally substituted (C5-C20)alkenyl. In embodiments, R12Cis optionally substituted (C10- 25 C20)alkenyl. In embodiments, R12Cis optionally substituted (C15-C20)alkenyl. [000201] In embodiments, R12Cis -W1-X1. In embodiments, W1is a covalent bond. In embodiments, W1is optionally substituted (C1-C10)alkylene. In embodiments, W1is optionally substituted (C1-C8)alkylene. In embodiments, W1is optionally substituted (C1-C6)alkylene. In embodiments, W1is optionally substituted (C1-C5)alkylene. In embodiments, W1is optionally30 substituted (C2-C10)alkenylene. In embodiments, W1is optionally substituted (C2- C8)alkenylene. In embodiments, W1is optionally substituted (C2-C6)alkenylene. In embodiments, W1is optionally substituted (C2-C5)alkenylene. In embodiments, X1is -(*C=O)- O-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally 35 substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted74 (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C25)alkenyl, wherein the atom 5 marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In 10 embodiments, X1is -(*C=O)-O-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkyl, wherein the atom marked15 with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is - *O-(C=O)-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted 20 (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In 25 embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C10-C18)alkenyl, wherein the atom 30 marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. [000202] In embodiments, R12Dis optionally substituted (C1-C25)alkyl. In embodiments, R12Dis optionally substituted (C5-C25)alkyl. In embodiments, R12Dis optionally substituted (C5-C20)alkyl. In embodiments, R12Dis optionally substituted (C5-C15)alkyl. In embodiments, R12Dis optionally substituted (C6-C12)alkyl. In embodiments, R12Dis optionally substituted 35 (C8-C10)alkyl.75 [000203] In embodiments, R12Dis optionally substituted (C2-C25)alkenyl. In embodiments, R12Dis optionally substituted (C5-C25)alkenyl. In embodiments, R12Dis optionally substituted (C5-C20)alkenyl. In embodiments, R12Dis optionally substituted (C10- C20)alkenyl. In embodiments, R12Dis optionally substituted (C15-C20)alkenyl. 5 [000204] In embodiments, R12Dis -W1-X1. In embodiments, W1is a covalent bond. In embodiments, W1is optionally substituted (C1-C10)alkylene. In embodiments, W1is optionally substituted (C1-C8)alkylene. In embodiments, W1is optionally substituted (C1-C6)alkylene. In embodiments, W1is optionally substituted (C1-C5)alkylene. In embodiments, W1is optionally substituted (C2-C10)alkenylene. In embodiments, W1is optionally substituted (C2- 10 C8)alkenylene. In embodiments, W1is optionally substituted (C2-C6)alkenylene. In embodiments, W1is optionally substituted (C2-C5)alkenylene. In embodiments, X1is -(*C=O)- O-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- 15 when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C25)alkenyl, wherein the atom 20 marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In 25 embodiments, X1is -(*C=O)-O-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkyl, wherein the atom marked30 with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is - *O-(C=O)-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted 35 (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkenyl,76 wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkenyl, wherein the atom 5 marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond. 10 [000205] In embodiments, each R12A, R12B, R12Cand R12Dis independently selected from: 15 , 20(x) ,77 5(xvii) , for example wherein each R12A, R12B, R12Cand R12Dis option (iii). [000206] In embodiments, R12A, R12B, R12Cand R12Dare the same. In embodiments,10 R12Aand R12Bare the same and R12Cand R12Dare the same. In embodiments, R12Aand R12Care the same and R12Band R12Dare the same. In embodiments, R12Aand R12Care the same and R12Band R12Dare different. [000207] The cationic lipids of the present invention also include compounds having a structure according to Formula (V): 15Formula (V) or a pharmaceutically acceptable salt thereof,78 wherein: r and s are integers that are each independently selected from 1, 2, 3, 4, 5 or 6; each Y5is independently selected from hydrogen or -OH; R15is optionally substituted (C1-C3)alkylene-optionally substituted bicyclic heteroaryl; 5 R16is hydrogen; R14A, R14B, R14C, and R14Dare each independently selected from optionally substituted (C5-C25)alkyl, optionally substituted (C5-C25)alkenyl, or -W1-X1; each W1is independently selected from a covalent bond, optionally substituted (C1- C10)alkylene or optionally substituted (C2-C10)alkenylene; and 10 each X1is independently selected from -(*C=O)-O-optionally substituted (C3-C25)alkyl, -(*C=O)-O-optionally substituted (C3-C25)alkenyl, -*O-(C=O)-optionally substituted (C3-C25)alkyl, or -*O-(C=O)-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. 15 [000208] In embodiments, the cationic lipids of the present invention include compounds having a structure according to Formula (V) wherein R15is optionally substituted (C1-C3)alkylene-optionally substituted indolyl. In embodiments, the cationic lipids of the present invention include compounds having a structure according to Formula (V) wherein R15is unsubstituted (C1)alkylene-unsubstituted indolyl. 20 [000209] In embodiments, the cationic lipids of the present invention include compounds having a structure according to Formula (V) wherein Y5= H. [000210] In embodiments, the cationic lipids of the present invention include compounds having a structure according to Formula (V) wherein Y5= H and R15is optionally substituted (C1-C3)alkylene-optionally substituted indolyl. 25 [000211] In embodiments, the cationic lipids of the present invention include compounds having a structure according to Formula (V) wherein Y5= H and R15is unsubstituted (C1)alkylene-unsubstituted indolyl. [000212] In embodiments, the cationic lipids of the present invention include compounds having a structure according to Formula (VA):79Formula (VA) or a pharmaceutically acceptable salt thereof. [000213] In embodiments, the cationic lipids of the present invention include 5 compounds having a structure according to Formula (VA) wherein R15is optionally substituted (C1-C3)alkylene-optionally substituted indolyl. In embodiments, the cationic lipids of the present invention include compounds having a structure according to Formula (VA) wherein R15is unsubstituted (C1)alkylene-unsubstituted indolyl. [000214] In embodiments, the cationic lipids of the present invention include10compounds having a structure according to Formula (VA1):or a pharmaceutically acceptable salt thereof. [000215] In embodiments, the cationic lipids of the present invention include 15 compounds having a structure according to Formula (VB):80Formula (VB) or a pharmaceutically acceptable salt thereof. [000216] In embodiments, r is 3 or 4. In embodiments, r is 3. In embodiments, r is 4. In 5 embodiments, r is 1. In embodiments, r is 2. In embodiments, r is 5. In embodiments, r is 6. [000217] In embodiments, s is 3 or 4. In embodiments, s is 3. In embodiments, s is 4. In embodiments, s is 1. In embodiments, s is 2. In embodiments, s is 5. In embodiments, s is 6. [000218] In embodiments, r and s are each independently 3 or 4. In embodiments, r10and s are each 3. In embodiments, r and s are each 4. [000219] In embodiments, Y5is hydrogen. [000220] In embodiments, R15is an optionally substituted (C1-C3)alkylene-optionally substituted indolyl. In embodiments, R15is an unsubstituted (C1)alkylene-unsubstituted indolyl.15[000221] In embodiments, R14Ais optionally substituted (C5-C25)alkyl. In embodiments, R14Ais optionally substituted (C5-C20)alkyl. In embodiments, R14Ais optionally substituted (C5-C15)alkyl. In embodiments, R14Ais optionally substituted (C6-C12)alkyl. In embodiments, R14Ais optionally substituted (C8-C10)alkyl. [000222] In embodiments, R14Ais optionally substituted (C5-C25)alkenyl. In 20 embodiments, R14Ais optionally substituted (C5-C20)alkenyl. In embodiments, R14Ais optionally substituted (C10-C20)alkenyl. In embodiments, R14Ais optionally substituted (C15- C20)alkenyl. [000223] In embodiments, R14Ais -W1-X1. In embodiments, W1is a covalent bond. In embodiments, W1is optionally substituted (C1-C10)alkylene. In embodiments, W1is optionally 25 substituted (C1-C8)alkylene. In embodiments, W1is optionally substituted (C1-C6)alkylene. In embodiments, W1is optionally substituted (C1-C5)alkylene. In embodiments, W1is optionally81 substituted (C2-C10)alkenylene. In embodiments, W1is optionally substituted (C2- C8)alkenylene. In embodiments, W1is optionally substituted (C2-C6)alkenylene. In embodiments, W1is optionally substituted (C2-C5)alkenylene. In embodiments, X1is -(*C=O)- O-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W15or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C18)alkyl, wherein 10 the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In 15 embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C18)alkenyl, wherein the atom 20 marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is - *O-(C=O)-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally 25 substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent 30 bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C10-C20)alkenyl, wherein the atom 35 marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In82 embodiments, X1is -*O-(C=O)-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. [000224] In embodiments, R14Bis optionally substituted (C5-C25)alkyl. In embodiments, R14Bis optionally substituted (C5-C20)alkyl. In embodiments, R14Bis optionally substituted 5 (C5-C15)alkyl. In embodiments, R14Bis optionally substituted (C6-C12)alkyl. In embodiments, R14Bis optionally substituted (C8-C10)alkyl. [000225] In embodiments, R14Bis optionally substituted (C5-C25)alkenyl. In embodiments, R14Bis optionally substituted (C5-C20)alkenyl. In embodiments, R14Bis optionally substituted (C10-C20)alkenyl. In embodiments, R14Bis optionally substituted (C15- 10 C20)alkenyl. [000226] In embodiments, R14Bis -W1-X1. In embodiments, W1is a covalent bond. In embodiments, W1is optionally substituted (C1-C10)alkylene. In embodiments, W1is optionally substituted (C1-C8)alkylene. In embodiments, W1is optionally substituted (C1-C6)alkylene. In embodiments, W1is optionally substituted (C1-C5)alkylene. In embodiments, W1is optionally15 substituted (C2-C10)alkenylene. In embodiments, W1is optionally substituted (C2- C8)alkenylene. In embodiments, W1is optionally substituted (C2-C6)alkenylene. In embodiments, W1is optionally substituted (C2-C5)alkenylene. In embodiments, X1is -(*C=O)- O-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally 20 substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In 25 embodiments, X1is -(*C=O)-O-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkenyl, wherein the atom 30 marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In 35 embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -83 *O-(C=O)-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted 5 (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In 10 embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C10-C18)alkenyl, wherein the atom 15 marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. [000227] In embodiments, R14Cis optionally substituted (C5-C25)alkyl. In embodiments, R14Cis optionally substituted (C5-C20)alkyl. In embodiments, R14Cis optionally substituted (C5-C15)alkyl. In embodiments, R14Cis optionally substituted (C6-C12)alkyl. In embodiments, R14Cis optionally substituted (C8-C10)alkyl. 20 [000228] In embodiments, R14Cis optionally substituted (C5-C25)alkenyl. In embodiments, R14Cis optionally substituted (C5-C20)alkenyl. In embodiments, R14Cis optionally substituted (C10-C20)alkenyl. In embodiments, R14Cis optionally substituted (C15- C20)alkenyl. [000229] In embodiments, R14Cis -W1-X1. In embodiments, W1is a covalent bond. In 25 embodiments, W1is optionally substituted (C1-C10)alkylene. In embodiments, W1is optionally substituted (C1-C8)alkylene. In embodiments, W1is optionally substituted (C1-C6)alkylene. In embodiments, W1is optionally substituted (C1-C5)alkylene. In embodiments, W1is optionally substituted (C2-C10)alkenylene. In embodiments, W1is optionally substituted (C2- C8)alkenylene. In embodiments, W1is optionally substituted (C2-C6)alkenylene. In 30 embodiments, W1is optionally substituted (C2-C5)alkenylene. In embodiments, X1is -(*C=O)- O-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted 35 (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C18)alkyl, wherein84 the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkenyl, wherein the atom 5 marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In 10 embodiments, X1is -(*C=O)-O-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is - *O-(C=O)-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected 15 to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkenyl, 20 wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In 25 embodiments, X1is -*O-(C=O)-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. [000230] In embodiments, R14Dis optionally substituted (C5-C25)alkyl. In embodiments, 30 R14Dis optionally substituted (C5-C20)alkyl. In embodiments, R14Dis optionally substituted (C5-C15)alkyl. In embodiments, R14Dis optionally substituted (C6-C12)alkyl. In embodiments, R14Dis optionally substituted (C8-C10)alkyl. [000231] In embodiments, R14Dis optionally substituted (C5-C25)alkenyl. In embodiments, R14Dis optionally substituted (C5-C20)alkenyl. In embodiments, R14Dis35 optionally substituted (C10-C20)alkenyl. In embodiments, R14Dis optionally substituted (C15- C20)alkenyl.85 [000232] In embodiments, R14Dis -W1-X1. In embodiments, W1is a covalent bond. In embodiments, W1is optionally substituted (C1-C10)alkylene. In embodiments, W1is optionally substituted (C1-C8)alkylene. In embodiments, W1is optionally substituted (C1-C6)alkylene. In embodiments, W1is optionally substituted (C1-C5)alkylene. In embodiments, W1is optionally 5 substituted (C2-C10)alkenylene. In embodiments, W1is optionally substituted (C2- C8)alkenylene. In embodiments, W1is optionally substituted (C2-C6)alkenylene. In embodiments, W1is optionally substituted (C2-C5)alkenylene. In embodiments, X1is -(*C=O)- O-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally 10 substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In 15 embodiments, X1is -(*C=O)-O-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkenyl, wherein the atom 20 marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In 25 embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is - *O-(C=O)-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- 30 when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C20)alkenyl, wherein the 35 atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkenyl, wherein the atom86 marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C10-C18)alkenyl, wherein the atom 5 marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond. [000233] In embodiments, each R14A, R14B, R14Cand R14Dis independently selected from: 10 15875 (xvii) , for example wherein each R14A, R14B, R14Cand R14Dis option (x), or wherein R14Aand R14Care option (xv) and R14Band R14Dare option (viii). [000234] In embodiments, R14A, R14B, R14Cand R14Dare the same. In embodiments, R14Aand R14Bare the same and R14Cand R14Dare the same. In embodiments, R14Aand R14C10 are the same and R14Band R14Dare the same. In embodiments, R14Aand R14Care the same and R14Band R14Dare different. [000235] The cationic lipids of the present invention also include compounds having a structure according to Formula (VI):15Formula (VI) or a pharmaceutically acceptable salt thereof, wherein: t and u are integers that are each independently selected from 1, 2, 3, 4, 5 or 6; each Y6is independently selected from hydrogen or -OH;88 R19is selected from optionally substituted (C1-C3)alkylene-optionally substituted thiazolyl and optionally substituted (C1-C3)alkylene-substituted phenyl, wherein the phenyl is substituted with one or more halogen atoms (e.g. -F); R18A, R18B, R18C, and R18Dare each independently selected from optionally substituted 5 (C5-C25)alkyl, optionally substituted (C5-C25)alkenyl, or -W1-X1; each W1is independently selected from a covalent bond, optionally substituted (C1- C10)alkylene or optionally substituted (C2-C10)alkenylene; and each X1is independently selected from -(*C=O)-O-optionally substituted (C3-C25)alkyl, -(*C=O)-O-optionally substituted (C3-C25)alkenyl, -*O-(C=O)-optionally 10 substituted (C3-C25)alkyl, or -*O-(C=O)-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. [000236] In embodiments, the cationic lipids of the present invention include compounds having a structure according to Formula (VI) wherein R19is unsubstituted (C1)alkylene-substituted phenyl, wherein the phenyl is substituted with one fluoro 15 substituent. [000237] In embodiments, the cationic lipids of the present invention include compounds having a structure according to Formula (VI) wherein Y6is H and R19is unsubstituted (C1)alkylene-substituted phenyl, wherein the phenyl is substituted with one fluoro substituent. 20 [000238] In embodiments, the cationic lipids of the present invention include compounds having a structure according to Formula (VIA):Formula (VIA) or a pharmaceutically acceptable salt thereof. 25 [000239] In embodiments, the cationic lipids of the present invention include compounds having a structure according to Formula (VIA1):89Formula (VIA1) or a pharmaceutically acceptable salt thereof. [000240] In embodiments, the cationic lipids of the present invention include 5 compounds having a structure according to Formula (VI) wherein R19is unsubstituted (C1)alkylene-unsubstituted thiazolyl. [000241] In embodiments, the cationic lipids of the present invention include compounds having a structure according to Formula (VI) wherein Y6is H and R19is unsubstituted (C1)alkylene-unsubstituted thiazolyl. 10 [000242] In embodiments, the cationic lipids of the present invention include compounds having a structure according to Formula (VIB):Formula (VIB) or a pharmaceutically acceptable salt thereof. 15 [000243] In embodiments, the cationic lipids of the present invention include compounds having a structure according to Formula (VIB1):90Formula (VIB1) or a pharmaceutically acceptable salt thereof. [000244] In embodiments, t is 4. In embodiments, t is 1. In embodiments, t is 2. In 5 embodiments, t is 3. In embodiments, t is 5. In embodiments, t is 6. [000245] In embodiments, u is 3. In embodiments, u is 1. In embodiments, u is 2. In embodiments, u is 4. In embodiments, u is 5. In embodiments, u is 6. [000246] In embodiments, t is 4 and u is 3. [000247] In embodiments, Y6is hydrogen. 10 [000248] In embodiments, R19is optionally substituted (C1-C3)alkylene-optionally substituted thiazolyl. In embodiments, R19is unsubstituted (C1)alkylene-unsubstituted thiazolyl. [000249] In embodiments, R19is optionally substituted (C1-C3)alkylene-substituted phenyl, wherein the phenyl is substituted with one or more halogen atoms (e.g. -F). In 15 embodiments, R19is unsubstituted (C1)alkylene-substituted phenyl, wherein the phenyl is substituted with one fluoro substituent. In embodiments, the alkylene and the fluoro are para (1,4-arrangement) on the substituted phenyl. [000250] In embodiments, R18Ais optionally substituted (C5-C25)alkyl. In embodiments, R18Ais optionally substituted (C5-C20)alkyl. In embodiments, R18Ais optionally substituted 20 (C5-C15)alkyl. In embodiments, R18Ais optionally substituted (C6-C12)alkyl. In embodiments, R18Ais optionally substituted (C8-C10)alkyl. [000251] In embodiments, R18Ais optionally substituted (C5-C25)alkenyl. In embodiments, R18Ais optionally substituted (C5-C20)alkenyl. In embodiments, R18Ais optionally substituted (C10-C20)alkenyl. In embodiments, R18Ais optionally substituted (C15- 25 C20)alkenyl. [000252] In embodiments, R18Ais -W1-X1. In embodiments, W1is a covalent bond. In embodiments, W1is optionally substituted (C1-C10)alkylene. In embodiments, W1is optionally substituted (C1-C8)alkylene. In embodiments, W1is optionally substituted (C1-C6)alkylene. In embodiments, W1is optionally substituted (C1-C5)alkylene. In embodiments, W1is optionally91 substituted (C2-C10)alkenylene. In embodiments, W1is optionally substituted (C2- C8)alkenylene. In embodiments, W1is optionally substituted (C2-C6)alkenylene. In embodiments, W1is optionally substituted (C2-C5)alkenylene. In embodiments, X1is -(*C=O)- O-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W15or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C18)alkyl, wherein 10 the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In 15 embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C18)alkenyl, wherein the atom 20 marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is - *O-(C=O)-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally 25 substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent 30 bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C10-C20)alkenyl, wherein the atom 35 marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In92 embodiments, X1is -*O-(C=O)-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. [000253] In embodiments, R18Bis optionally substituted (C5-C25)alkyl. In embodiments, R18Bis optionally substituted (C5-C20)alkyl. In embodiments, R18Bis optionally substituted 5 (C5-C15)alkyl. In embodiments, R18Bis optionally substituted (C6-C12)alkyl. In embodiments, R18Bis optionally substituted (C8-C10)alkyl. [000254] In embodiments, R18Bis optionally substituted (C5-C25)alkenyl. In embodiments, R18Bis optionally substituted (C5-C20)alkenyl. In embodiments, R18Bis optionally substituted (C10-C20)alkenyl. In embodiments, R18Bis optionally substituted (C15- 10 C20)alkenyl. [000255] In embodiments, R18Bis -W1-X1. In embodiments, W1is a covalent bond. In embodiments, W1is optionally substituted (C1-C10)alkylene. In embodiments, W1is optionally substituted (C1-C8)alkylene. In embodiments, W1is optionally substituted (C1-C6)alkylene. In embodiments, W1is optionally substituted (C1-C5)alkylene. In embodiments, W1is optionally15 substituted (C2-C10)alkenylene. In embodiments, W1is optionally substituted (C2- C8)alkenylene. In embodiments, W1is optionally substituted (C2-C6)alkenylene. In embodiments, W1is optionally substituted (C2-C5)alkenylene. In embodiments, X1is -(*C=O)- O-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally 20 substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In 25 embodiments, X1is -(*C=O)-O-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkenyl, wherein the atom 30 marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In 35 embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -93 *O-(C=O)-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted 5 (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In 10 embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C10-C18)alkenyl, wherein the atom 15 marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. [000256] In embodiments, R18Cis optionally substituted (C5-C25)alkyl. In embodiments, R18Cis optionally substituted (C5-C20)alkyl. In embodiments, R18Cis optionally substituted (C5-C15)alkyl. In embodiments, R18Cis optionally substituted (C6-C12)alkyl. In embodiments, R18Cis optionally substituted (C8-C10)alkyl. 20 [000257] In embodiments, R18Cis optionally substituted (C5-C25)alkenyl. In embodiments, R18Cis optionally substituted (C5-C20)alkenyl. In embodiments, R18Cis optionally substituted (C10-C20)alkenyl. In embodiments, R18Cis optionally substituted (C15- C20)alkenyl. [000258] In embodiments, R18Cis -W1-X1. In embodiments, W1is a covalent bond. In 25 embodiments, W1is optionally substituted (C1-C10)alkylene. In embodiments, W1is optionally substituted (C1-C8)alkylene. In embodiments, W1is optionally substituted (C1-C6)alkylene. In embodiments, W1is optionally substituted (C1-C5)alkylene. In embodiments, W1is optionally substituted (C2-C10)alkenylene. In embodiments, W1is optionally substituted (C2- C8)alkenylene. In embodiments, W1is optionally substituted (C2-C6)alkenylene. In 30 embodiments, W1is optionally substituted (C2-C5)alkenylene. In embodiments, X1is -(*C=O)- O-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted 35 (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C18)alkyl, wherein94 the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkenyl, wherein the atom 5 marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In 10 embodiments, X1is -(*C=O)-O-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is - *O-(C=O)-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected 15 to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkenyl, 20 wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In 25 embodiments, X1is -*O-(C=O)-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. [000259] In embodiments, R18Dis optionally substituted (C5-C25)alkyl. In embodiments, 30 R18Dis optionally substituted (C5-C20)alkyl. In embodiments, R18Dis optionally substituted (C5-C15)alkyl. In embodiments, R18Dis optionally substituted (C6-C12)alkyl. In embodiments, R18Dis optionally substituted (C8-C10)alkyl. [000260] In embodiments, R18Dis optionally substituted (C5-C25)alkenyl. In embodiments, R18Dis optionally substituted (C5-C20)alkenyl. In embodiments, R18Dis35 optionally substituted (C10-C20)alkenyl. In embodiments, R18Dis optionally substituted (C15- C20)alkenyl.95 [000261] In embodiments, R18Dis -W1-X1. In embodiments, W1is a covalent bond. In embodiments, W1is optionally substituted (C1-C10)alkylene. In embodiments, W1is optionally substituted (C1-C8)alkylene. In embodiments, W1is optionally substituted (C1-C6)alkylene. In embodiments, W1is optionally substituted (C1-C5)alkylene. In embodiments, W1is optionally 5 substituted (C2-C10)alkenylene. In embodiments, W1is optionally substituted (C2- C8)alkenylene. In embodiments, W1is optionally substituted (C2-C6)alkenylene. In embodiments, W1is optionally substituted (C2-C5)alkenylene. In embodiments, X1is -(*C=O)- O-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally 10 substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In 15 embodiments, X1is -(*C=O)-O-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C3-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C5-C20)alkenyl, wherein the atom 20 marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -(*C=O)-O-optionally substituted (C10-C18)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In 25 embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is - *O-(C=O)-optionally substituted (C3-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- 30 when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C18)alkyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C3-C20)alkenyl, wherein the 35 atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C5-C20)alkenyl, wherein the atom96 marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C10-C20)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. In embodiments, X1is -*O-(C=O)-optionally substituted (C10-C18)alkenyl, wherein the atom 5 marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond. [000262] In embodiments, each R18A, R18B, R18Cand R18Dis independently selected from: 10 15975 (xvii) , for example wherein R18Aand R18Care option (xi) and R18Band R18Dare option (viii). [000263] In embodiments, R18A, R18B, R18Cand R18Dare the same. In embodiments, R18Aand R18Bare the same and R18Cand R18Dare the same. In embodiments, R18Aand R18Care the same and R18Band R18Dare the same. In embodiments, R18Aand R18Care the same 10 and R18Band R18Dare different. [000264] In embodiments, each W1in W1-X1of any of the Formulae defined herein is independently selected from a covalent bond, optionally substituted (C1-C10)alkylene or optionally substituted (C2-C10)alkenylene; and each X1in W1-X1of any of the Formulae defined herein is independently selected 15 from -(*C=O)-O-optionally substituted (C3-C25) branched alkyl, -(*C=O)-O-optionally substituted (C3-C25) branched alkenyl, -*O-(C=O)-optionally substituted (C3-C25) branched alkyl, or -*O-(C=O)-optionally substituted (C3-C25) branched alkenyl, wherein the atom marked with a * is connected to W1or any one of -CH(Y1)-, -CH(Y2)-, -CH(Y3)- or -CH(Y4)- when W1is a covalent bond. 20 [000265] In embodiments, the substituents are not optionally substituted. [000266] In embodiments, the cationic lipids of the present invention have any one of the structures in Table A or Table B, or a pharmaceutically acceptable salt thereof. [000267] In embodiments, the cationic lipids of the present invention have any one of the structures in Table A, Table B or Table C, or a pharmaceutically acceptable salt thereof. 25 [000268] In embodiments, provided herein is a composition comprising a cationic lipid of the present invention, and further comprising: (i) one or more non-cationic lipids,98 (ii) one or more cholesterol-based lipids and (iii) one or more PEG-modified lipids. [000269] In embodiments, this composition is a lipid nanoparticle, optionally a liposome. In embodiments, the one or more cationic lipid(s) constitute(s) about 30 mol %-60 5 mol % of the lipid nanoparticle. In embodiments, the one or more non-cationic lipid(s) constitute(s) 10 mol%-50 mol% of the lipid nanoparticle. In embodiments, the one or more PEG-modified lipid(s) constitute(s) 1 mol%-10 mol% of the lipid nanoparticle. In embodiments, the cholesterol-based lipid constitutes 10 mol%-50 mol% of the lipid nanoparticle. 10 [000270] In embodiments, the lipid nanoparticle encapsulates a nucleic acid, optionally an mRNA encoding a peptide or protein. In embodiments, the peptide is an antigen. In embodiments, the lipid nanoparticle encapsulates an mRNA encoding a peptide or protein. As used herein, the phrase “encapsulation percentage” refers to the fraction of therapeutic agent (e.g. mRNA) that is effectively encapsulated within a liposomal-based vehicle (e.g. a 15 lipid nanoparticle) relative to the initial fraction of therapeutic agent present in the lipid phase. In embodiments, the lipid nanoparticles have an encapsulation percentage for mRNA of at least 50%. In embodiments, the lipid nanoparticles have an encapsulation percentage for mRNA of at least 55%. In embodiments, the lipid nanoparticles have an encapsulation percentage for mRNA of at least 60%. In embodiments, the lipid nanoparticles have an 20 encapsulation percentage for mRNA of at least 65%. In embodiments, the lipid nanoparticles have an encapsulation percentage for mRNA of at least 70%. In embodiments, the lipid nanoparticles have an encapsulation percentage for mRNA of at least 75%. In embodiments, the lipid nanoparticles have an encapsulation percentage for mRNA of at least 80%. In embodiments, the lipid nanoparticles have an encapsulation percentage for mRNA of at 25 least 85%. In embodiments, the lipid nanoparticles have an encapsulation percentage for mRNA of at least 90%. In embodiments, the lipid nanoparticles have an encapsulation percentage for mRNA of at least 95%. In embodiments, the encapsulation percentage is calculated by performing the Ribogreen assay (Invitrogen) with and without the presence of 0.1% Triton-X 100. 30 [000271] In embodiments, the composition of the present invention is for use in a vaccine. [000272] In embodiments, the composition of the present invention is for use in therapy. [000273] In embodiments, the composition of the present invention is for use in a 35 method of treating or preventing a disease amenable to treatment or prevention by the peptide or protein encoded by the mRNA, optionally wherein the disease is (a) a protein99 deficiency, optionally wherein the protein deficiency affects the liver, lung, brain or muscle, (b) an autoimmune disease, (c) an infectious disease, or (d) cancer. [000274] In embodiments, a method for treating or preventing a disease is provided, wherein said method comprises administering to a subject in need thereof a composition of 5 the present invention and wherein the disease is amenable to treatment or prevention by the peptide or protein encoded by the mRNA, optionally wherein the disease is (a) a protein deficiency, optionally wherein the protein deficiency affects the liver, lung, brain or muscle, (b) an autoimmune disease, (c) an infectious disease, or (d) cancer. [000275] In embodiments, the composition is administered intranasally, intravenously, 10 intrathecally or intramuscularly, or by pulmonary delivery, optionally through nebulization. In embodiments, the composition is administered intramuscularly. Exemplary Compounds [000276] In embodiments, the cationic lipids of the present invention include compounds selected from those depicted in Table A or Table B, or a pharmaceutically 15 acceptable salt thereof. [000277] In embodiments, the cationic lipids of the present invention include compounds selected from those depicted in Table A, Table B or Table C, or a pharmaceutically acceptable salt thereof. [000278] Exemplary compounds include those described in Table A, or a 20 pharmaceutically acceptable salt thereof. Table A100101102103104105106107108 [000279] Any of the compounds identified in Table A above may be provided in the form of a pharmaceutically acceptable salt and such salts are intended to be encompassed by the present invention. 5 Table B109110111112113114[000280] Any of the compounds identified in Table B above may be provided in the form of a pharmaceutically acceptable salt and such salts are intended to be encompassed by the present invention. 5 [000281] Table C115116117118119120 [000282] Any of the compounds identified in Table C above may be provided in the form of a pharmaceutically acceptable salt and such salts are intended to be encompassed by the present invention. [000283] The compounds of the invention as described herein can be prepared 5 according to methods known in the art, including the exemplary syntheses of the Examples provided herein. Nucleic Acids [000284] The compounds of the invention as described herein can be used to prepare 10 compositions useful for the delivery of nucleic acids. Synthesis of Nucleic Acids [000285] Nucleic acids according to the present invention may be synthesized according to any known methods. For example, mRNAs according to the present invention may be synthesized via in vitro transcription (IVT). Briefly, IVT is typically performed with a 15 linear or circular DNA template containing a promoter, a pool of ribonucleotide triphosphates, a buffer system that may include DTT and magnesium ions, and an appropriate RNA polymerase (e.g., T3, T7, mutated T7 or SP6 RNA polymerase), DNAse I, pyrophosphatase, and / or RNAse inhibitor. The exact conditions will vary according to the specific application. [000286] In some embodiments, for the preparation of mRNA according to the 20 invention, a DNA template is transcribed in vitro. A suitable DNA template typically has a promoter, for example a T3, T7, mutated T7 or SP6 promoter, for in vitro transcription, followed by desired nucleotide sequence for desired mRNA and a termination signal. [000287] Desired mRNA sequence(s) according to the invention may be determined and incorporated into a DNA template using standard methods. For example, starting from a 25 desired amino acid sequence (e.g., an enzyme sequence), a virtual reverse translation is carried out based on the degenerated genetic code. Optimization algorithms may then be used for selection of suitable codons. Typically, the G / C content can be optimized to achieve the highest possible G / C content on one hand, taking into the best possible account the frequency of the tRNAs according to codon usage on the other hand. The optimized 30 RNA sequence can be established and displayed, for example, with the aid of an appropriate display device and compared with the original (wild-type) sequence. A secondary structure can also be analyzed to calculate stabilizing and destabilizing properties or, respectively, regions of the RNA. Modified mRNA 35 [000288] In some embodiments, mRNA according to the present invention may be synthesized as unmodified or modified mRNA. Modified mRNA comprises nucleotide121 modifications in the RNA. A modified mRNA according to the invention can thus include nucleotide modification that are, for example, backbone modifications, sugar modifications or base modifications. In some embodiments, mRNAs may be synthesized from naturally occurring nucleotides and / or nucleotide analogues (modified nucleotides) including, but not 5 limited to, purines (adenine (A), guanine (G)) or pyrimidines (thymine (T), cytosine (C), uracil (U)), and as modified nucleotides analogues or derivatives of purines and pyrimidines, such as e.g., 1-methyl-adenine, 2-methyl-adenine, 2-methylthio-N-6-isopentenyl-adenine, N6- methyl-adenine, N6-isopentenyl-adenine, 2-thio-cytosine, 3-methyl-cytosine, 4-acetyl- cytosine, 5-methyl-cytosine, 2,6-diaminopurine, 1-methyl-guanine, 2-methyl-guanine, 2,2- 10 dimethyl-guanine, 7-methyl-guanine, inosine, 1-methyl-inosine, pseudouracil (5-uracil), dihydro-uracil, 2-thio-uracil, 4-thio-uracil, 5-carboxymethylaminomethyl-2-thio-uracil, 5- (carboxyhydroxymethyl)-uracil, 5-fluoro-uracil, 5-bromo-uracil, 5-carboxymethylaminomethyl- uracil, 5-methyl-2-thio-uracil, 5-methyl-uracil, N-uracil-5-oxyacetic acid methyl ester, 5- methylaminomethyl-uracil, 5-methoxyaminomethyl-2-thio-uracil, 5'-methoxycarbonylmethyl-15 uracil, 5-methoxy-uracil, uracil-5-oxyacetic acid methyl ester, uracil-5-oxyacetic acid (v), 1- methyl-pseudouracil, queuosine, beta-D-mannosyl-queuosine, wybutoxosine, and phosphoramidates, phosphorothioates, peptide nucleotides, methylphosphonates, 7- deazaguanosine, 5-methylcytosine and inosine. The preparation of such analogues is known to a person skilled in the art e.g., from the U.S. Pat. No. 4,373,071, U.S. Pat. No. 20 4,401,796, U.S. Pat. No.4,415,732, U.S. Pat. No.4,458,066, U.S. Pat. No.4,500,707, U.S. Pat. No. 4,668,777, U.S. Pat. No. 4,973,679, U.S. Pat. No. 5,047,524, U.S. Pat. No. 5,132,418, U.S. Pat. No.5,153,319, U.S. Pat. Nos. 5,262,530 and 5,700,642, the disclosures of which are incorporated by reference in their entirety. 25 Pharmaceutical Formulations of Cationic Lipids and Nucleic Acids [000289] In certain embodiments, the compounds of the invention as described herein, as well as pharmaceutical and liposomal compositions comprising such lipids, can be used in formulations to facilitate the delivery of encapsulated materials (e.g., one or more polynucleotides such as mRNA) to, and subsequent transfection of one or more target cells. 30 For example, in certain embodiments cationic lipids described herein (and compositions such as liposomal compositions comprising such lipids) are characterized as resulting in one or more of receptor-mediated endocytosis, clathrin-mediated and caveolae-mediated endocytosis, phagocytosis and macropinocytosis, fusogenicity, endosomal or lysosomal disruption and / or releasable properties that afford such compounds advantages relative 35 other similarly classified lipids.122 [000290] According to the present invention, a nucleic acid, e.g., mRNA encoding a protein (e.g., a full length, fragment or portion of a protein) as described herein may be delivered via a delivery vehicle comprising a compound of the invention as described herein. [000291] As used herein, the terms “delivery vehicle,” “transfer vehicle,” “nanoparticle,” 5 or grammatical equivalents thereof, are used interchangeably. [000292] For example, the present invention provides a composition (e.g., a pharmaceutical composition) comprising a compound described herein and one or more polynucleotides. A composition (e.g., a pharmaceutical composition) may further comprise one or more cationic lipids, one or more non-cationic lipids, one or more cholesterol-based 10 lipids and / or one or more PEG-modified lipids. [000293] In certain embodiments a composition exhibits an enhanced (e.g., increased) ability to transfect one or more target cells. Accordingly, also provided herein are methods of transfecting one or more target cells. Such methods generally comprise the step of contacting the one or more target cells with the cationic lipids and / or pharmaceutical 15 compositions disclosed herein (e.g., a liposomal formulation comprising a compound described herein encapsulating one or more polynucleotides) such that the one or more target cells are transfected with the materials encapsulated therein (e.g., one or more polynucleotides). As used herein, the terms “transfect” or “transfection” refer to the intracellular introduction of one or more encapsulated materials (e.g., nucleic acids and / or 20 polynucleotides) into a cell (e.g., into a target cell). The introduced polynucleotide may be stably or transiently maintained in the target cell. The term “transfection efficiency” refers to the relative amount of such encapsulated material (e.g., polynucleotides) up-taken by, introduced into, and / or expressed by the target cell which is subject to transfection. In practice, transfection efficiency may be estimated by the amount of a reporter polynucleotide 25 product produced by the target cells following transfection. In certain embodiments, the compounds and pharmaceutical compositions described herein demonstrate high transfection efficiencies thereby improving the likelihood that appropriate dosages of the encapsulated materials (e.g., one or more polynucleotides) will be delivered to the site of pathology and subsequently expressed, while at the same time minimizing potential 30 systemic adverse effects or toxicity associated with the compound or their encapsulated contents. [000294] Following transfection of one or more target cells by, for example, the polynucleotides encapsulated in the one or more lipid nanoparticles comprising the pharmaceutical or liposomal compositions disclosed herein, the production of the product 35 (e.g., a polypeptide or protein) encoded by such polynucleotide may be stimulated and the capability of such target cells to express the polynucleotide and produce, for example, a123 polypeptide or protein of interest is enhanced. For example, transfection of a target cell by one or more compounds or pharmaceutical compositions encapsulating mRNA will enhance (i.e., increase) the production of the protein or enzyme encoded by such mRNA. [000295] Further, delivery vehicles described herein (e.g., liposomal delivery vehicles) 5 may be prepared to preferentially distribute to other target tissues, cells or organs, such as the heart, lungs, kidneys, spleen. In embodiments, the lipid nanoparticles of the present invention may be prepared to achieve enhanced delivery to the target cells and tissues. For example, polynucleotides (e.g., mRNA) encapsulated in one or more of the compounds or pharmaceutical and liposomal compositions described herein can be delivered to and / or 10 transfect targeted cells or tissues. In some embodiments, the encapsulated polynucleotides (e.g., mRNA) are capable of being expressed and functional polypeptide products produced (and in some instances excreted) by the target cell, thereby conferring a beneficial property to, for example the target cells or tissues. Such encapsulated polynucleotides (e.g., mRNA) may encode, for example, a hormone, enzyme, receptor, polypeptide, peptide or other 15 protein of interest. Liposomal Delivery Vehicles [000296] In some embodiments, a composition is a suitable delivery vehicle. In embodiments, a composition is a liposomal delivery vehicle, e.g., a lipid nanoparticle. 20 [000297] The terms “liposomal delivery vehicle” and “liposomal composition” are used interchangeably. [000298] Enriching liposomal compositions with one or more of the cationic lipids disclosed herein may be used as a means of improving the safety profile or otherwise conferring one or more desired properties to such enriched liposomal composition (e.g., 25 improved delivery of the encapsulated polynucleotides to one or more target cells and / or reduced in vivo toxicity of a liposomal composition). Accordingly, also contemplated are pharmaceutical compositions, and in particular liposomal compositions, that comprise one or more of the cationic lipids disclosed herein. [000299] Thus, in certain embodiments, the compounds of the invention as described 30 herein may be used as a component of a liposomal composition to facilitate or enhance the delivery and release of encapsulated materials (e.g., one or more therapeutic agents) to one or more target cells (e.g., by permeating or fusing with the lipid membranes of such target cells). [000300] As used herein, liposomal delivery vehicles, e.g., lipid nanoparticles, are 35 usually characterized as microscopic vesicles having an interior aqua space sequestered from an outer medium by a membrane of one or more bilayers. Bilayer membranes of124 liposomes are typically formed by amphiphilic molecules, such as lipids of synthetic or natural origin that comprise spatially separated hydrophilic and hydrophobic domains (Lasic, Trends Biotechnol., 16: 307-321, 1998). Bilayer membranes of the liposomes can also be formed by amphophilic polymers and surfactants (e.g., polymerosomes, niosomes, etc.). In 5 the context of the present invention, a liposomal delivery vehicle typically serves to transport a desired mRNA to a target cell or tissue. [000301] In certain embodiments, such compositions (e.g., liposomal compositions) are loaded with or otherwise encapsulate materials, such as for example, one or more biologically-active polynucleotides (e.g., mRNA). 10 [000302] In embodiments, a composition (e.g., a pharmaceutical composition) comprises an mRNA encoding a protein, encapsulated within a liposome. In embodiments, a liposome comprises one or more cationic lipids, one or more non-cationic lipids, one or more cholesterol-based lipids and one or more PEG-modified lipids, and wherein at least one cationic lipid is a compound of the invention as described herein. In embodiments, a 15 composition comprises an mRNA encoding for a peptide or protein (e.g., any peptide or protein described herein). In embodiments, a composition comprises an mRNA encoding for a peptide (e.g., any peptide described herein). In embodiments, a composition comprises an mRNA encoding for a protein (e.g., any protein described herein). [000303] In embodiments, a composition (e.g., a pharmaceutical composition) 20 comprises a nucleic acid encapsulated within a liposome, wherein the liposome comprises a compound described herein. [000304] In embodiments, a nucleic acid is an mRNA encoding a peptide or protein. In embodiments, an mRNA encodes a peptide or protein for use in the delivery to or treatment of the lung of a subject or a lung cell. In embodiments, an mRNA encodes a peptide or 25 protein for use in the delivery to or treatment of the liver of a subject or a liver cell. Still other exemplary mRNAs are described herein. [000305] In embodiments, a liposomal delivery vehicle (e.g., a lipid nanoparticle) can have a net positive charge. [000306] In embodiments, a liposomal delivery vehicle (e.g., a lipid nanoparticle) can 30 have a net negative charge. [000307] In embodiments, a liposomal delivery vehicle (e.g., a lipid nanoparticle) can have a net neutral charge. [000308] In embodiments, a lipid nanoparticle that encapsulates a nucleic acid (e.g., mRNA encoding a peptide or protein) comprises one or more compounds of the invention as 35 described herein.125 [000309] For example, the amount of a compound of the invention as described herein in a composition can be described as a percentage (“wt%”) of the combined dry weight of all lipids of a composition (e.g., the combined dry weight of all lipids present in a liposomal composition). 5 [000310] In embodiments of the pharmaceutical compositions described herein, a compound of the invention as described herein is present in an amount that is about 0.5 wt% to about 30 wt% (e.g., about 0.5 wt% to about 20 wt%) of the combined dry weight of all lipids present in a composition (e.g., a liposomal composition). [000311] In embodiments, a compound of the invention as described herein is present 10 in an amount that is about 1 wt% to about 30 wt%, about 1 wt% to about 20 wt%, about 1 wt% to about 15 wt%, about 1 wt% to about 10 wt%, or about 5 wt% to about 25 wt% of the combined dry weight of all lipids present in a composition (e.g., a liposomal composition). In embodiments, a compound of the invention as described herein is present in an amount that is about 0.5 wt% to about 5 wt%, about 1 wt% to about 10 wt%, about 5 wt% to about 15 20 wt%, or about 10 wt% to about 20 wt% of the combined dry weight of all lipids present in a composition such as a liposomal delivery vehicle. [000312] In embodiments, the amount of a compound of the invention as described herein is present in an amount that is at least about 5 wt%, about 10 wt%, about 15 wt%, about 20 wt%, about 25 wt%, about 30 wt%, about 35 wt%, about 40 wt%, about 45 wt%, 20 about 50 wt%, about 55 wt%, about 60 wt%, about 65 wt%, about 70 wt%, about 75 wt%, about 80 wt%, about 85 wt%, about 90 wt%, about 95 wt%, about 96 wt%, about 97 wt%, about 98 wt%, or about 99 wt% of the combined dry weight of total lipids in a composition (e.g., a liposomal composition). [000313] In embodiments, the amount of a compound of the invention as described 25 herein is present in an amount that is no more than about 5 wt%, about 10 wt%, about 15 wt%, about 20 wt%, about 25 wt%, about 30 wt%, about 35 wt%, about 40 wt%, about 45 wt%, about 50 wt%, about 55 wt%, about 60 wt%, about 65 wt%, about 70 wt%, about 75 wt%, about 80 wt%, about 85 wt%, about 90 wt%, about 95 wt%, about 96 wt%, about 97 wt%, about 98 wt%, or about 99 wt% of the combined dry weight of total lipids in a 30 composition (e.g., a liposomal composition). [000314] In embodiments, a composition (e.g., a liposomal delivery vehicle such as a lipid nanoparticle) comprises about 0.1 wt% to about 20 wt% (e.g., about 0.1 wt% to about 15 wt%) of a compound described herein. In embodiments, a delivery vehicle (e.g., a liposomal delivery vehicle such as a lipid nanoparticle) comprises about 0.5 wt%, about 1 35 wt%, about 3 wt%, about 5 wt%, or about 10 wt% of a compound described herein. In embodiments, a delivery vehicle (e.g., a liposomal delivery vehicle such as a lipid126 nanoparticle) comprises up to about 0.5 wt%, about 1 wt%, about 3 wt%, about 5 wt%, about 10 wt%, about 15 wt%, or about 20 wt% of a compound described herein. In embodiments, the percentage results in an improved beneficial effect (e.g., improved delivery to targeted tissues such as the liver or the lung). 5 [000315] The amount of a compound of the invention as described herein in a composition also can be described as a percentage (“mol%”) of the combined molar amounts of total lipids of a composition (e.g., the combined molar amounts of all lipids present in a liposomal delivery vehicle). [000316] In embodiments of pharmaceutical compositions described herein, a 10 compound of the invention as described herein is present in an amount that is about 0.5 mol% to about 50 mol% (e.g., about 0.5 mol% to about 20 mol%) of the combined molar amounts of all lipids present in a composition such as a liposomal delivery vehicle. [000317] In embodiments, a compound of the invention as described herein is present in an amount that is about 0.5 mol% to about 5 mol%, about 1 mol% to about 10 mol%, 15 about 5 mol% to about 20 mol%, about 10 mol% to about 20 mol%, about 15 mol% to about 30 mol%, about 20 mol% to about 35 mol%, about 25 mol% to about 40 mol%, about 30 mol% to about 45 mol%, about 35 mol% to about 50 mol%, about 40 mol% to about 55 mol %, or about 45 mol% to about 60 mol% of the combined molar amounts of all lipids present in a composition such as a liposomal delivery vehicle. In embodiments, a compound of the 20 invention as described herein is present in an amount that is about 1 mol% to about 60 mol%, 1 mol% to about 50 mol%, 1 mol% to about 40 mol%, 1 mol% to about 30 mol%, about 1 mol% to about 20 mol%, about 1 mol% to about 15 mol%, about 1 mol% to about 10 mol%, about 5 mol% to about 55 mol%, about 5 mol% to about 45 mol%, about 5 mol% to about 35 mol% or about 5 mol% to about 25 mol% of the combined molar amounts of all 25 lipids present in a composition such as a liposomal delivery vehicle [000318] In certain embodiments, a compound of the invention as described herein can comprise from about 0.1 mol% to about 50 mol%, or from 0.5 mol% to about 50 mol%, or from about 1 mol% to about 50 mol%, or from about 5 mol% to about 50 mol%, or from about 10 mol% to about 50 mol%, or from about 15 mol% to about 50 mol%, or from about 30 20 mol% to about 50 mol%, or from about 25 mol% to about 50 mol%, or from about 30 mol% to about 50 mol%, of the total amount of lipids in a composition (e.g., a liposomal delivery vehicle). [000319] In certain embodiments, a compound of the invention as described herein can comprise greater than about 0.1 mol%, or greater than about 0.5 mol%, or greater than 35 about 1 mol%, greater than about 5 mol%, greater than about 10 mol%, greater than about127 20 mol%, greater than about 30 mol%, or greater than about 40 mol% of the total amount of lipids in the lipid nanoparticle. [000320] In certain embodiments, a compound as described can comprise less than about 60 mol%, or less than about 55 mol%, or less than about 50 mol%, or less than about 5 45 mol%, or less than about 40 mol%, or less than about 35 mol %, less than about 30 mol%, or less than about 25 mol%, or less than about 10 mol%, or less than about 5 mol%, or less than about 1 mol% of the total amount of lipids in a composition (e.g., a liposomal delivery vehicle). [000321] In embodiments, the amount of a compound of the invention as described 10 herein is present in an amount that is at least about 5 mol%, about 10 mol%, about 15 mol%, about 20 mol%, about 25 mol%, about 30 mol%, about 35 mol%, about 40 mol%, about 45 mol%, about 50 mol%, about 55 mol%, about 60 mol%, about 65 mol%, about 70 mol%, about 75 mol%, about 80 mol%, about 85 mol%, about 90 mol%, about 95 mol%, about 96 mol%, about 97 mol%, about 98 mol%, or about 99 mol% of the combined molar amounts 15 of total lipids in a composition (e.g., a liposomal composition). [000322] In embodiments, the amount of a compound of the invention as described herein is present in an amount that is no more than about 5 mol%, about 10 mol%, about 15 mol%, about 20 mol%, about 25 mol%, about 30 mol%, about 35 mol%, about 40 mol%, about 45 mol%, about 50 mol%, about 55 mol%, about 60 mol%, about 65 mol%, about 20 70 mol%, about 75 mol%, about 80 mol%, about 85 mol%, about 90 mol%, about 95 mol%, about 96 mol%, about 97 mol%, about 98 mol%, or about 99 mol% of the combined molar amounts of total lipids in a composition (e.g., a liposomal composition). [000323] In embodiments, the percentage results in an improved beneficial effect (e.g., improved delivery to targeted tissues such as the liver or the lung). 25 In a typical embodiment, a composition of the invention (e.g., a liposomal composition) comprises one or more cationic lipids, one or more non-cationic lipids, one or more cholesterol-based lipids, and one or more PEG-modified lipids, wherein at least one cationic lipid is a compound of the invention as described herein. For example, a composition suitable for practicing the invention has four lipid components comprising a compound of the 30 invention as described herein as the cationic lipid component, a non-cationic lipid, a cholesterol-based lipid, and a PEG-modified lipid. The non-cationic lipid may be DOPE or DEPE. The cholesterol-based lipid may be cholesterol. The PEG-modified lipid may be DMG-PEG2K. [000324] In further embodiments, pharmaceutical (e.g., liposomal) compositions 35 comprise one or more of a PEG-modified lipid, a non-cationic lipid and a cholesterol lipid. In other embodiments, such pharmaceutical (e.g., liposomal) compositions comprise: one or128 more PEG-modified lipids; one or more non-cationic lipids; and one or more cholesterol lipids. In yet further embodiments, such pharmaceutical (e.g., liposomal) compositions comprise: one or more PEG-modified lipids and one or more cholesterol lipids. [000325] In embodiments, a composition (e.g., lipid nanoparticle) that encapsulates a 5 nucleic acid (e.g., mRNA encoding a peptide or protein) comprises one or more compounds of the invention as described herein, and one or more lipids selected from the group consisting of a cationic lipid, a non-cationic lipid, and a PEGylated lipid. [000326] In embodiments, a composition (e.g., lipid nanoparticle) that encapsulates a nucleic acid (e.g., mRNA encoding a peptide or protein) comprises one or more compound 10 of the invention as described herein; one or more lipids selected from the group consisting of a cationic lipid, a non-cationic lipid, and a PEGylated lipid; and further comprises a cholesterol-based lipid. Typically, such a composition has four lipid components comprising a compound of the invention as described herein as the cationic lipid component, a non- cationic lipid (e.g., DOPE), a cholesterol-based lipid (e.g., cholesterol) and a PEG-modified 15 lipid (e.g., DMG-PEG2K). [000327] In embodiments, a lipid nanoparticle that encapsulates a nucleic acid (e.g., mRNA encoding a peptide or protein) comprises one or more compounds of the invention as described herein, as well as one or more lipids selected from the group consisting of a cationic lipid, a non-cationic lipid, a PEGylated lipid, and a cholesterol-based lipid. 20 [000328] According to various embodiments, the selection of cationic lipids, non- cationic lipids and / or PEG-modified lipids which comprise the lipid nanoparticle, as well as the relative molar ratio of such lipids to each other, is based upon the characteristics of the selected lipid(s), the nature of the intended target cells, the characteristics of the mRNA to be delivered. Additional considerations include, for example, the saturation of the alkyl 25 chain, as well as the size, charge, pH, pKa, fusogenicity and toxicity of the selected lipid(s). Thus, the molar ratios may be adjusted accordingly. Cationic Lipids [000329] In addition to any of the compounds of the invention as described herein, a 30 composition may comprise one or more additional cationic lipids. [000330] In some embodiments, liposomes may comprise one or more additional cationic lipids. As used herein, the phrase “cationic lipid” refers to any of a number of lipid species that have a net positive charge at a selected pH, such as physiological pH. Several cationic lipids have been described in the literature, many of which are commercially 35 available.129 [000331] Suitable additional cationic lipids for use in the compositions include the cationic lipids as described in the literature. Helper Lipids 5 [000332] Compositions (e.g., liposomal compositions) may also comprise one or more helper lipids. Such helper lipids include non-cationic lipids. As used herein, the phrase “non- cationic lipid” refers to any neutral, zwitterionic or anionic lipid. As used herein, the phrase “anionic lipid” refers to any of a number of lipid species that carry a net negative charge at a selected pH, such as physiological pH. Non-cationic lipids include, but are not limited to, 10 distearoylphosphatidylcholine (DSPC), dioleoylphosphatidylcholine (DOPC), dipalmitoylphosphatidylcholine (DPPC), dioleoylphosphatidylglycerol (DOPG), dipalmitoylphosphatidylglycerol (DPPG), dioleoylphosphatidylethanolamine (DOPE), 1,2- Dierucoyl-sn-glycero-3-phosphoethanolamine (DEPE), palmitoyloleoylphosphatidylcholine (POPC), palmitoyloleoyl-phosphatidylethanolamine (POPE), dioleoyl- 15 phosphatidylethanolamine 4-(N-maleimidomethyl)-cyclohexane-1-carboxylate (DOPE-mal), dipalmitoyl phosphatidyl ethanolamine (DPPE), dimyristoylphosphoethanolamine (DMPE), distearoyl-phosphatidyl-ethanolamine (DSPE), 16-O-monomethyl PE, 16-O-dimethyl PE, 18- 1-trans PE, 1-stearoyl-2-oleoyl-phosphatidyethanolamine (SOPE), or a mixture thereof. A non-cationic or helper lipid suitable for practicing the invention is 20 dioleoylphosphatidylethanolamine (DOPE). Alternatively, 1,2-Dierucoyl-sn-glycero-3- phosphoethanolamine (DEPE) can be used as a non-cationic or helper lipid. [000333] In some embodiments, a non-cationic lipid is a neutral lipid, i.e., a lipid that does not carry a net charge in the conditions under which the composition is formulated and / or administered. 25 [000334] In some embodiments, a non-cationic lipid may be present in a molar ratio (mol%) of about 5% to about 90%, about 5% to about 70%, about 5% to about 50%, about 5% to about 40%, about 5% to about 30%, about 10% to about 70%, about 10% to about 50%, or about 10% to about 40% of the total lipids present in a composition. In some embodiments, total non-cationic lipids may be present in a molar ratio (mol%) of about 5% to 30 about 90%, about 5% to about 70%, about 5% to about 50%, about 5% to about 40%, about 5% to about 30%, about 10 % to about 70%, about 10% to about 50%, or about 10% to about 40% of the total lipids present in a composition. In some embodiments, the percentage of non-cationic lipid in a liposome may be greater than about 5 mol%, greater than about 10 mol%, greater than about 20 mol%, greater than about 30 mol%, or greater 35 than about 40 mol%. In some embodiments, the percentage total non-cationic lipids in a liposome may be greater than about 5 mol%, greater than about 10 mol%, greater than130 about 20 mol%, greater than about 30 mol%, or greater than about 40 mol%. In some embodiments, the percentage of non-cationic lipid in a liposome is no more than about 5 mol%, no more than about 10 mol%, no more than about 20 mol%, no more than about 30 mol%, or no more than about 40 mol%. In some embodiments, the percentage total non- 5 cationic lipids in a liposome may be no more than about 5 mol%, no more than about 10 mol%, no more than about 20 mol%, no more than about 30 mol%, or no more than about 40 mol%. [000335] In some embodiments, a non-cationic lipid may be present in a weight ratio (wt%) of about 5% to about 90%, about 5% to about 70%, about 5% to about 50%, about 10 5% to about 40%, about 5% to about 30%, about 10 % to about 70%, about 10% to about 50%, or about 10% to about 40% of the total lipids present in a composition. In some embodiments, total non-cationic lipids may be present in a weight ratio (wt%) of about 5% to about 90%, about 5% to about 70%, about 5% to about 50%, about 5% to about 40%, about 5% to about 30%, about 10 % to about 70%, about 10% to about 50%, or about 10% to 15 about 40% of the total lipids present in a composition. In some embodiments, the percentage of non-cationic lipid in a liposome may be greater than about 5 wt%, greater than about 10 wt%, greater than about 20 wt%, greater than about 30 wt%, or greater than about 40 wt%. In some embodiments, the percentage total non-cationic lipids in a liposome may be greater than about 5 wt%, greater than about 10 wt%, greater than about 20 wt%, greater 20 than about 30 wt%, or greater than about 40 wt%. In some embodiments, the percentage of non-cationic lipid in a liposome is no more than about 5 wt%, no more than about 10 wt%, no more than about 20 wt%, no more than about 30 wt%, or no more than about 40 wt%. In some embodiments, the percentage total non-cationic lipids in a liposome may be no more than about 5 wt%, no more than about 10 wt%, no more than about 20 wt%, no more than 25 about 30 wt%, or no more than about 40 wt%. Cholesterol-based Lipids [000336] In some embodiments, a composition (e.g., a liposomal composition) comprises one or more cholesterol-based lipids. For example, a suitable cholesterol-based 30 lipid for practicing the invention is cholesterol. Other suitable cholesterol-based lipids include, for example, DC-Chol (N,N-dimethyl-N-ethylcarboxamidocholesterol), 1,4-bis(3-N- oleylamino-propyl)piperazine (Gao, et al. Biochem. Biophys. Res. Comm. 179, 280 (1991); Wolf et al. BioTechniques 23, 139 (1997); U.S. Pat. No. 5,744,335), beta-sitosterol, delta 5 avenasterol, or imidazole cholesterol ester (ICE), which has the following structure,131[000337] In some embodiments, a cholesterol-based lipid may be present in a molar ratio (mol%) of about 1% to about 30%, or about 5% to about 20% of the total lipids present in a liposome. In some embodiments, the percentage of cholesterol-based lipid in the lipid 5 nanoparticle may be greater than about 5 mol%, greater than about 10 mol%, greater than about 20 mol%, greater than about 30 mol%, or greater than about 40 mol%. In some embodiments, the percentage of cholesterol-based lipid in the lipid nanoparticle may be no more than about 5 mol%, no more than about 10 mol%, no more than about 20 mol%, no more than about 30 mol%, or no more than about 40 mol%. 10 [000338] In some embodiments, a cholesterol-based lipid may be present in a weight ratio (wt%) of about 1% to about 30%, or about 5% to about 20% of the total lipids present in a liposome. In some embodiments, the percentage of cholesterol-based lipid in the lipid nanoparticle may be greater than about 5 wt%, greater than about 10 wt%, greater than about 20 wt%, greater than about 30 wt%, or greater than about 40 wt%. In some 15 embodiments, the percentage of cholesterol-based lipid in the lipid nanoparticle may be no more than about 5 wt%, no more than about 10 wt%, no more than about 20 wt%, no more than about 30 wt%, or no more than about 40 wt%. PEGylated Lipids 20 [000339] In some embodiments, a composition (e.g., a liposomal composition) comprises one or more further PEGylated lipids. A suitable PEG-modified or PEGylated lipid for practicing the invention is 1,2-dimyristoyl-rac-glycero-3-methoxypolyethylene glycol-2000 (DMG-PEG2K). [000340] For example, the use of polyethylene glycol (PEG)-modified phospholipids25 and derivatized lipids such as derivatized ceramides (PEG-CER), including N-octanoyl- sphingosine-1-[succinyl(methoxy polyethylene glycol)-2000] (C8 PEG-2000 ceramide) is also contemplated by the present invention in combination with one or more of compounds of the invention as described herein and, in some embodiments, other lipids together which comprise the liposome. In some embodiments, particularly useful exchangeable lipids are 30 PEG-ceramides having shorter acyl chains (e.g., C14or C18).132 [000341] Contemplated further PEG-modified lipids (also referred to herein as a PEGylated lipid, which term is interchangeable with PEG-modified lipid) include, but are not limited to, a polyethylene glycol chain of up to 5 kDa in length covalently attached to a lipid with alkyl chain(s) of C6-C20 length. In some embodiments, a PEG-modified or PEGylated 5 lipid is PEGylated cholesterol or PEG-2K. The addition of such components may prevent complex aggregation and may also provide a means for increasing circulation lifetime and increasing the delivery of the lipid-nucleic acid composition to the target cell, (Klibanov et al. (1990) FEBS Letters, 268 (1): 235-237), or they may be selected to rapidly exchange out of the formulation in vivo (see U.S. Pat. No. 5,885,613). 10 [000342] Further PEG-modified phospholipid and derivatized lipids of the present invention may be present in a molar ratio (mol%) from about 0% to about 10%, about 0.5% to about 10%, about 1% to about 10%, about 2% to about 10%, or about 3% to about 5% of the total lipid present in the composition (e.g., a liposomal composition). 15 Pharmaceutical Formulations and Therapeutic Uses [000343] Compounds of the invention as described herein may be used in the preparation of compositions (e.g., to construct liposomal compositions) that facilitate or enhance the delivery and release of encapsulated materials (e.g., one or more therapeutic polynucleotides) to one or more target cells (e.g., by permeating or fusing with the lipid 20 membranes of such target cells). [000344] For example, when a liposomal composition (e.g., a lipid nanoparticle) comprises or is otherwise enriched with one or more of the compounds disclosed herein, the phase transition in the lipid bilayer of the one or more target cells may facilitate the delivery of the encapsulated materials (e.g., one or more therapeutic polynucleotides encapsulated in 25 a lipid nanoparticle) into the one or more target cells. [000345] Similarly, in certain embodiments compounds of the invention as described herein may be used to prepare liposomal vehicles that are characterized by their reduced toxicity in vivo. In certain embodiments, the reduced toxicity is a function of the high transfection efficiencies associated with the compositions disclosed herein, such that a 30 reduced quantity of such composition may be administered to the subject to achieve a desired therapeutic response or outcome. [000346] Thus, pharmaceutical formulations comprising a compound described and nucleic acids provided by the present invention may be used for various therapeutic disease and / or disease prevention purposes. To facilitate delivery of nucleic acids in vivo, a 35 compound described herein and nucleic acids can be formulated in combination with one or more additional pharmaceutical carriers, targeting ligands or stabilizing reagents. In some133 embodiments, a compound described herein can be formulated via pre-mixed lipid solution. In other embodiments, a composition comprising a compound described herein can be formulated using post-insertion techniques into the lipid membrane of the nanoparticles. Techniques for formulation and administration of drugs may be found in “Remington’s 5 Pharmaceutical Sciences,” Mack Publishing Co., Easton, Pa., latest edition. [000347] Suitable routes of administration include, for example, oral, rectal, vaginal, transmucosal, pulmonary including intratracheal or inhaled, or intestinal administration; parenteral delivery, including intradermal, transdermal (topical), intramuscular, subcutaneous, intramedullary injections, as well as intrathecal, direct intraventricular, 10 intravenous, intraperitoneal, or intranasal. In particular embodiments, the intramuscular administration is to a muscle selected from the group consisting of skeletal muscle, smooth muscle and cardiac muscle. In some embodiments the administration results in delivery of the nucleic acids to a muscle cell. In some embodiments the administration results in delivery of the nucleic acids to a hepatocyte (i.e., liver cell). 15 [000348] A common route for administering a liposomal composition of the invention may be intravenous delivery, in particular when treating metabolic disorders, especially those affecting the liver (e.g., ornithine transcarbamylase (OTC) deficiency). Alternatively, depending on the disease or disorder to be treated, the liposomal composition may be administered via pulmonary delivery (e.g., for the treatment of cystic fibrosis). For 20 vaccination, a liposomal composition of the invention is typically administered intramuscularly. Alternatively, a liposomal composition of the invention may be administered intranasally for vaccination. Diseases or disorders affecting the eye may be treated by administering a liposomal composition of the invention intravitreally. [000349] Alternatively or additionally, pharmaceutical formulations of the invention may 25 be administered in a local rather than systemic manner, for example, via injection of the pharmaceutical formulation directly into a targeted tissue (e.g., in a sustained release formulation). Local delivery can be affected in various ways, depending on the tissue to be targeted. Exemplary tissues in which mRNA may be delivered and / or expressed include, but are not limited to the liver, kidney, heart, spleen, serum, brain, skeletal muscle, lymph nodes, 30 skin, and / or cerebrospinal fluid. In embodiments, the tissue to be targeted in the liver. For example, aerosols containing compositions of the present invention can be inhaled (for nasal, tracheal, or bronchial delivery); compositions of the present invention can be injected into the site of injury, disease manifestation, or pain, for example; compositions can be provided in lozenges for oral, tracheal, or esophageal application; can be supplied in liquid, 35 tablet or capsule form for administration to the stomach or intestines, can be supplied in134 suppository form for rectal or vaginal application; or can even be delivered to the eye by use of creams, drops, or even injection. [000350] Compositions described herein can comprise mRNA encoding peptides including those described herein (e.g., a polypeptide such as a protein). 5 [000351] In embodiments, a mRNA encodes a polypeptide. [000352] In embodiments, a mRNA encodes a peptide. In embodiments, the peptide is an antigen. [000353] In embodiments, a mRNA encodes a protein. [000354] The present invention provides methods for delivering a composition having 10 full-length mRNA molecules encoding a peptide or protein of interest for use in the treatment of a subject, e.g., a human subject or a cell of a human subject or a cell that is treated and delivered to a human subject. Delivery Methods 15 [000355] The route of delivery used in the methods of the invention allows for non- invasive, self-administration of the compounds of the invention. In some embodiments, the methods involve intranasal, intratracheal or pulmonary administration by aerosolization, nebulization, or instillation of a compositions comprising mRNA encoding a therapeutic peptide or protein in a suitable transfection or lipid carrier vehicles as described above. In 20 some embodiments, the peptide or protein is encapsulated with a liposome. In some embodiments, the liposome comprises a lipid, which is a compound of the invention. As used herein below, administration of a compound of the invention includes administration of a composition comprising a compound of the invention. [000356] Although the local cells and tissues of the lung represent a potential target 25 capable of functioning as a biological depot or reservoir for production and secretion of the protein encoded by the mRNA, applicants have discovered that administration of the compounds of the invention to the lung via aerosolization, nebulization, or instillation results in the distribution of even non-secreted proteins outside the lung cells. Without wishing to be bound by any particular theory, it is contemplated that nanoparticle compositions of the 30 invention pass, through the lung airway-blood barrier, resulting in translation of the intact nanoparticle to non-lung cells and tissues, such as, e.g., the heart, the liver, the spleen, where it results in the production of the encoded peptide or protein in these non-lung tissues. Thus, the utility of the compounds of the invention and methods of the invention extend beyond production of therapeutic protein in lung cells and tissues of the lung and can be 35 used to delivery to non-lung target cells and / or tissues. They are useful in the management and treatment of a large number of diseases. In certain embodiments, the compounds of the135 invention, used in the methods of the invention result in the distribution of the mRNA encapsulated nanoparticles and production of the encoded peptide or protein in the liver, spleen, heart, and / or other non-lung cells. For example, administration of the compounds of the invention, by aerosolization, nebulization, or instillation to the lung will result in the 5 composition itself and its peptide or protein product (e.g., an antigen or functional protein) will be detectable in both the local cells and tissues of the lung, as well as in peripheral target cells, tissues and organs as a result of translocation of the mRNA and delivery vehicle to non-lung cells. [000357] In certain embodiments, the compounds of the invention may be employed in 10 the methods of the invention to specifically target peripheral cells or tissues. Following the pulmonary delivery, it is contemplated the compounds of the invention cross the lung airway- blood barrier and distribute into cells other than the local lung cells. Accordingly, the compounds disclosed herein may be administered to a subject by way of the pulmonary route of administration, using a variety of approach known by those skilled in the art (e.g., by 15 inhalation), and distribute to both the local target cells and tissues of the lung, as well as in peripheral non-lung cells and tissues (e.g., cells of the liver, spleen, kidneys, heart, skeletal muscle, lymph nodes, brain, cerebrospinal fluid, and plasma). As a result, both the local cells of the lung and the peripheral non-lung cells can serve as biological reservoirs or depots capable of producing and / or secreting a translation product encoded by one or more 20 polynucleotides. Accordingly, the present invention is not limited to the treatment of lung diseases or conditions, but rather can be used as a non-invasive means of facilitating the delivery of polynucleotides, or the production of peptides or proteins encoded thereby, in peripheral organs, tissues and cells (e.g., hepatocytes) which would otherwise be achieved only by systemic administration. Exemplary peripheral non-lung cells include, but are not 25 limited to, hepatocytes, epithelial cells, hematopoietic cells, epithelial cells, endothelial cells, bone cells, stem cells, mesenchymal cells, neural cells, cardiac cells, adipocytes, vascular smooth muscle cells, cardiomyocytes, skeletal muscle cells, beta cells, pituitary cells, synovial lining cells, ovarian cells, testicular cells, fibroblasts, B cells, T cells, reticulocytes, leukocytes, granulocytes and tumor cells. 30 [000358] Following administration of the composition to the subject, the peptide or protein product encoded by the mRNA (e.g., a functional protein or enzyme) is detectable in the peripheral target tissues for at least about one to seven days or longer following administration of the compound to the subject. The amount of peptide or protein product necessary to achieve a therapeutic effect will vary depending on the condition being treated, 35 the peptide or protein encoded, and the condition of the patient. For example, the peptide or protein product may be detectable in the peripheral target tissues at a concentration (e.g., a136 therapeutic concentration) of at least 0.025-1.5 µg / ml (e.g., at least 0.050 µg / ml, at least 0.075 µg / ml, at least 0.1 µg / ml, at least 0.2 µg / ml, at least 0.3 µg / ml, at least 0.4 µg / ml, at least 0.5 µg / ml, at least 0.6 µg / ml, at least 0.7 µg / ml, at least 0.8 µg / ml, at least 0.9 µg / ml, at least 1.0 µg / ml, at least 1.1 µg / ml, at least 1.2 µg / ml, at least 1.3 µg / ml, at least 1.4 µg / ml, or 5 at least 1.5 µg / ml), for at least about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 35, 40, 45 days or longer following administration of the compound to the subject. [000359] It has been demonstrated that nucleic acids can be delivered to the lungs by intratracheal administration of a liquid suspension of the compound and inhalation of an 10 aerosol mist produced by a liquid nebulizer or the use of a dry powder apparatus such as that described in U.S. patent 5,780,014, incorporated herein by reference. [000360] In certain embodiments, the compounds of the invention may be formulated such that they may be aerosolized or otherwise delivered as a particulate liquid or solid prior to or upon administration to the subject. Such compounds may be administered with the 15 assistance of one or more suitable devices for administering such solid or liquid particulate compositions (such as, e.g., an aerosolized aqueous solution or suspension) to generate particles that are easily respirable or inhalable by the subject. In some embodiments, such devices (e.g., a metered dose inhaler, jet-nebulizer, ultrasonic nebulizer, dry-powder- inhalers, propellant-based inhaler or an insufflator) facilitate the administration of a 20 predetermined mass, volume or dose of the compositions (e.g., about 0.5 mg / kg of mRNA per dose) to the subject. For example, in certain embodiments, the compounds of the invention are administered to a subject using a metered dose inhaler containing a suspension or solution comprising the compound and a suitable propellant. In certain embodiments, the compounds of the invention may be formulated as a particulate powder 25 (e.g., respirable dry particles) intended for inhalation. In certain embodiments, compositions of the invention formulated as respirable particles are appropriately sized such that they may be respirable by the subject or delivered using a suitable device (e.g., a mean D50 or D90 30 embodiments, the compounds of the invention are formulated to include one or more pulmonary surfactants (e.g., lamellar bodies). In some embodiments, the compounds of the invention are administered to a subject such that a concentration of at least 0.05 mg / kg, at least 0.1 mg / kg, at least 0.5 mg / kg, at least 1.0 mg / kg, at least 2.0 mg / kg, at least 3.0 mg / kg, at least 4.0 mg / kg, at least 5.0 mg / kg, at least 6.0 mg / kg, at least 7.0 mg / kg, at least 8.0 35 mg / kg, at least 9.0 mg / kg, at least 10 mg / kg, at least 15 mg / kg, at least 20 mg / kg, at least 25 mg / kg, at least 30 mg / kg, at least 35 mg / kg, at least 40 mg / kg, at least 45 mg / kg, at least 50137 mg / kg, at least 55 mg / kg, at least 60 mg / kg, at least 65 mg / kg, at least 70 mg / kg, at least 75 mg / kg, at least 80 mg / kg, at least 85 mg / kg, at least 90 mg / kg, at least 95 mg / kg, or at least 100 mg / kg body weight is administered in a single dose. In some embodiments, the compounds of the invention are administered to a subject such that a total amount of at least 5 0.1 mg, at least 0.5 mg, at least 1.0 mg, at least 2.0 mg, at least 3.0 mg, at least 4.0 mg, at least 5.0 mg, at least 6.0 mg, at least 7.0 mg, at least 8.0 mg, at least 9.0 mg, at least 10 mg, at least 15 mg, at least 20 mg, at least 25 mg, at least 30 mg, at least 35 mg, at least 40 mg, at least 45 mg, at least 50 mg, at least 55 mg, at least 60 mg, at least 65 mg, at least 70 mg, at least 75 mg, at least 80 mg, at least 85 mg, at least 90 mg, at least 95 mg or at least 100 10 mg mRNA is administered in one or more doses. EXAMPLES [000361] While certain compounds, compositions and methods of the present invention have been described with specificity in accordance with certain embodiments, the following 15 examples serve only to illustrate the compounds of the invention and are not intended to limit the same. List of abbreviations: ACN: Acetonitrile 20 Boc: tert-Butyloxycarbonyl DCM: Dichloromethane EDC.HCl: 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride ELSD: Evaporative Light Scattering Detector EtOAc: Ethyl acetate 25 MeOH: Methanol Na2SO4: Sodium Sulfate NMR: Nuclear magnetic resonance spectroscopy RT: Room temperature SiO2: Silicon dioxide 30 SM: Starting material TFA: Trifluoroacetic Acid TLC: Thin Layer Chromatography TLC / ELSD: Thin Layer Chromatography / Evaporative Light Scattering Detector 35 EXAMPLES Example 1: Synthesis of Compound 1ı38Intermediate [2]:139[000362] In a 100 ml pressure vessel, a mixture of 2-(chloromethyl)-2-methyloxirane [1] (1.0 g, 9.39 mmol) and ammonium hydroxide (10 mL) (25%) was stirred at room temperature for 48 hours. After completion (monitored by TLC), the reaction mixture was 5 concentrated to remove the excess ammonia to obtain 1,3-diamino-2-methyl-2-propanol [2] (0.8 g crude), which was forward to the next step without further purification. Result: [000363]1H NMR (400 MHz, DMSO-d6(s, 3H) ppm. 10 Intermediate [5]:[000364] To a stirred solution of 4-aminobutyric acid [3] (2 g, 19.4 mmol) and 2- octyloxirane [4] (9.09 g, 58.2 mmol) in methanol (40 ml) was added ethylbis(propan-2- 15 yl)amine (10.1 mL, 58.2 mmol). The resultant reaction mixture was allowed to heated at 90 °C for 16 h. The reaction progress was monitor by TLC and ELSD. After the starting material was consumed, the reaction mixture was cool to RT and diluted it with tetrahydrofuran (80 ml) and water (40 ml) (2:1). The resulting solution was cooled to 0oC and lithium(1+) hydroxide (929 mg, 38.8 mmol) was added. After 4 h, the reaction progress was monitored 20 by TLC and ELSD. The reaction mixture was acidified using 2N hydrochloric acid to pH 2.0 and extracted with ethyl acetate. The organic layer was separated, dried over sodium sulphate and concentrated under reduced pressure to get crude compound. The crude compound was purified by flash column chromatography (SiO2: 0-5.0 % methanol in DCM) to afford 4-[bis(2-hydroxydecyl)amino] butyric acid [5] (6.0 g, 74.43 % Yield) as a colourless 25 sticky liquid. Result: [000365] ELSD analysis: Purity 96.12 %, Calculated C24H49NO4= 415.37, Observed = 416.4 (m / z, M+H+).140 Intermediate [6]:[000366] To a stirred solution of 4-[bis(2-hydroxydecyl)amino]butyric acid [5] (6.0 g, 5 14.4 mmol) in dichloromethane (100 mL) was added (tert-butyl)(chloro)bis(methyl)silane (21.8 g, 144 mmol) and imidazole (15.7 g, 231 mmol). The reaction mixture was stirred at room temperature for 16 hours. The progress of reaction was monitored with TLC and ELSD. After completion, the reaction mixture was quenched with water and extracted with DCM (3x100 mL). The organic layers were combined, dried over anhydrous Na2SO4,filtered 10 and concentrated to get crude. The crude residue was purified by flash column chromatography (SiO2: 10-20 % EtOAc in heptane) to obtain 4-(bis{2-[(tert- butyl)bis(methyl)siloxy]decyl} amino)butyric acid [6] (5.8 g, 62.37 % Yield) as a colourless liquid. Result: 15 [000367] ELSD analysis: Purity 99.81 %, Calculated C36H77NO4Si2= 643.54, Observed = 644.45 (m / z, M+H+). Intermediate [7]:20 [000368] To a stirred solution of 4-(bis{2-[(tert-butyl)bis(methyl)siloxy]decyl} amino)butyric acid [6] (1.7 g, 2.65 mmol) in dimethylformamide (5 ml) and dichloromethane (5 ml), were added N,N-dimethyl-4-pyridylamine (486 mg, 3.97 mmol) and 2-methyl-2,6,8- triaza-6,7-decadiene-hydrogen chloride (1 / 1) (762 mg, 3.97 mmol) at room temperature allow to stir for 15 min. After this 1,3-diamino-2-methyl-2-propanol (138 mg, 1.32 mmol) was 25 added into reaction mixture. The reaction mixture was stirred at room temperature for 16 hours. The progress of reaction was monitored by ELSD and TLC. After the completion, the141 reaction mixture was diluted with ice cold water and extracted with ethyl acetate (3x100 mL). The organic layers were combined, dried over Na2SO4, filtered and concentrated to get crude. The crude was purified by flash column chromatography (SiO2:10-20% EtOAc in heptane) to obtain N-{3-[4-(bis{2-[(tert-butyl)bis(methyl)siloxy]decyl}amino)butyrylamino]-2- 5 hydroxy-2-methylpropyl}4-(bis{2-[(tert-butyl)bis(methyl)siloxy]decyl}amino)butyramide [7] (350 mg, 19.47 % Yield) as a colourless sticky liquid. Result: [000369] ELSD analysis: Purity 98.94 %, Calculated C76H162N4O7Si4= 1355.15, Observed = 1356.85 (m / z, M+H+). 10 Compound 1:[000370] To a stirred solution of N-{3-[4-(bis{2-[(tert-15 butyl)bis(methyl)siloxy]decyl}amino) butyrylamino]-2-hydroxy-2-methylpropyl}4-(bis{2-[(tert- butyl)bis(methyl)siloxy]decyl} amino)butyramide (350 mg, 258 µmol) in tetrahydrofuran (5 ml) was added hydrogen fluoride-pyridine (1 / 1) (0.7 mL) dropwise under ice condition. After the addition, the reaction mixture was stirred at room temperature for 16 hours. The progress of reaction was monitored by ELSD and TLC. The reaction mixture was diluted with ice cold 20 water and extracted diethyl ether. The organic layer was basify using triethyl amine and washed with brine solution. The ether layer was concentrated under vacuum to yield N-(3-{4- [bis(2-hydroxydecyl)amino]butyrylamino}-2-hydroxy-2-methylpropyl)4-[bis(2- hydroxydecyl)amino]butyramide (180 mg, 77.56 % Yield) as an oily liquid. Result: 25 [000371]1H NMR (400 MHz, CDCl33.63 (m, 4H), 3.38-3.10 (m, 4H), 2.86-2.74 (m, 2H), 2.73-2.62 (m, 3H), 2.61-2.44 (m, 6H), 2.45-2.28 (m, 6H), 1.95-1.75 (m, 4H), 1.50-1.36 (m, 10H), 1.36-1.20 (m, 44H), 1.15 (s, 3H), 0.89-0.80 (t, J = 6.8 Hz, 12H).142 [000372] ELSD analysis: Purity 99.28 %, Calculated C52H106N4O7= 898.81, Observed = 899.66 (m / z, M+H+). Example 2: Synthesis of Compound 2ı43144 Intermediate [2]:[000373] In a 100 ml pressure vessel, a mixture of 2-(chloromethyl)-2-methyloxirane [1] (1.0 g, 9.39 mmol) and ammonium hydroxide (10 mL) (25%) was stirred at room 5 temperature for 48 hours. After completion (monitored by TLC), the reaction mixture was concentrated to remove the excess ammonia to obtain 1,3-diamino-2-methyl-2-propanol [2] (0.8 g crude), which was forward to the next step without further purification. Result: [000374]1H NMR (400 MHz, DMSO-d6 10 (s, 3H). Intermediate [5]:[000375] To a stirred solution of 4-aminobutyric acid (2.0 g, 19.4 mmol) and 2- 15 decyloxirane (10.7 g, 58.2 mmol) in methanol (40 ml) was added ethylbis(propan-2-yl)amine (10.1 mL, 58.2 mmol). The resultant reaction mixture was allowed to heat at 90 °C for 16 h. The reaction progress was monitored by TLC and ELSD. After the starting material was consumed, the reaction mixture was cool to RT and diluted it with tetrahydrofuran (80 ml), water (40 ml) (2:1). The resulting solution was cooled to 0oC and added lithium(1+) 20 hydroxide (929 mg, 38.8 mmol). After 4 h, the progress of reaction was monitored by TLC and ELSD. The reaction mixture was acidified using 2N hydrochloric acid to pH 2.0 and extracted with ethyl acetate. The organic layer was separated, dried over sodium sulphate and concentrated under reduced pressure to get crude compound. The Crude compound was purified by flash column chromatography (SiO2: 2.5-5.0 % methanol in DCM) to afford 4-25[bis(2-hydroxydodecyl)amino]butyric acid (4.3 g, 47.0 % Yield) as a colourless sticky liquid. Result:145 [000376] ELSD analysis: Purity 98.02 %, Calculated C28H57NO4 = 471.43, Observed = 472.4 (m / z, M+H+). Intermediate [6]: 5[000377] To a stirred solution of 4-[bis(2-hydroxydodecyl)amino]butyric acid (4.3 g, 9.11 mmol) in dichloromethane (100 mL) was added (tert-butyl)(chloro)bis(methyl)silane (13.7 g, 91.1 mmol) and imidazole (9.93 g, 146 mmol). The reaction mixture was stirred at room temperature for 16 hours. The progress of reaction was monitored by TLC and ELSD. 10 After the completion of the reaction, the reaction mixture was quenched with water and extracted with DCM (3x 100 mL). The organic layer was dried over anhydrous Na2SO4,filtered and concentrated. The crude residue was purified by flash column chromatography (SiO2: 10-20% EtOAc in heptane) to obtain 4-(bis{2-[(tert- butyl)bis(methyl)siloxy]dodecyl}amino)butyric acid [6] (5.1 g, 79.9 % Yield) as a colourless 15 liquid. Result: [000378] ELSD analysis: Purity 96.08 %, Calculated C40H85NO4Si2= 699.60, Observed = 700.50 (m / z, M+H+). 20 Intermediate [7]:[000379] To a stirred solution of 4-(bis{2-[(tert- butyl)bis(methyl)siloxy]dodecyl}amino)butyric acid [6] (2.02 g, 2.88 mmol) in dimethylformamide (5.0 mL) and dichloromethane (5.0 mL) was added 2-methyl-2,6,8-triaza-25 6,7-decadiene-hydrogen chloride (1 / 1) (828 mg, 4.32 mmol) and N,N-dimethyl-4- pyridylamine (528 mg, 4.32 mmol) at room temperature allow to stir for 15 min. After this 1,3-146 diamino-2-methyl-2-propanol [2] (150 mg, 1.44 mmol) was added into reaction mixture. The reaction mixture was stirred at room temperature for 16 hours. The progress of reaction was monitored by ELSD and TLC. After the completion, the reaction mixture was diluted with ice cold water and extracted with ethyl acetate (3x100 mL). The organic layers were combined, 5 dried over Na2SO4, filtered and concentrated to get crude. The crude was purified by flash column chromatography (SiO2:10-20% EtOAc in heptane) to obtain N-{3-[4-(bis{2-[(tert butyl)bis(methyl)siloxy]dodecyl} amino)butyrylamino]-2-hydroxy-2-methylpropyl}4-(bis{2- [(tert-butyl)bis(methyl)siloxy] dodecyl}amino)butyramide [7] (0.7 g, 33.0 % Yield) as a colourless sticky liquid. 10 Result: [000380] ELSD analysis: Purity 99.34 %, Calculated C84H178N4O7Si4= 1467.28, Observed = 1468.85 (m / z, M+H+). Compound 2: 15[000381] To a stirred solution of N-{3-[5-(bis{2-[(tert-butyl)bis(methyl)siloxy] dodecyl}amino)valerylamino]-2-hydroxy-2-methylpropyl}5-(bis{2-[(tert-butyl)bis(methyl) siloxy]dodecyl}amino)valeramide [7] (0.7 g, 468 µmol) in tetrahydrofuran (7 ml) was added 20 hydrogen fluoride pyridine (1.4 mL) dropwise under ice condition. After the addition, the reaction mixture was stirred at room temperature for 16 hours. The progress of reaction was monitored using ELSD and TLC. The reaction mixture was diluted with ice cold water and extracted with diethyl ether. The organic layer was basify using triethyl amine to pH 8-9 and was organic layer was washed with brine solution. The organic layer was concentrated25 under vacuum to yield N-(3-{5-[bis(2-hydroxydodecyl)amino]valerylamino}-2-hydroxy-2- methylpropyl)5-[bis(2-hydroxydodecyl)amino]valeramide (430 mg, 98.72 % Yield) as pale yellow liquid. Result:147 [000382]1H NMR (400 MHz, CDCl3 4H), 3.30-3.16 (m, 6H), 3.15-3.07 (m, 4H), 3.05-2.95 (m, 2H), 2.63-2.41 (m, 4H), 2.21-2.04 (m, 4H), 1.54-1.39 (m, 15H), 1.32-1.24 (m, 57H), 1.17 (s, 3H), 0.89-0.86 (t, J = 6.8 Hz, 12H). [000383] ELSD analysis: Purity 99.28 %, Calculated C60H122N4O7 = 1010.93, Observed 5 = 1011.95 (m / z, M+H+).ı48 Example 3: Synthesis of Compound 3149 Intermediate [2]:[000384] In a 100 ml pressure vessel, a mixture of 2-(chloromethyl)-2-methyloxirane [1] (1.0 g, 9.39 mmol) and ammonium hydroxide (10 mL) (25%) was stirred at room 5 temperature for 48 hours. After completion (monitored by TLC), the reaction mixture was concentrated to remove the excess ammonia to obtain 1,3-diamino-2-methyl-2-propanol [2] (0.8 g crude), which was forward to the next step without further purification. Result: [000385]1H NMR (400 MHz, DMSO-d6 10 (s, 3H). Intermediate [5]:[000386] To stirred a solution of 5-aminovaleric acid [3] (1.82 mL, 17.1 mmol) and 2-15 octyloxirane [4] (7.94 mL, 42.7 mmol) in methanol (50 mL) was added N- ethylbis(isopropyl)amine (8.49 mL, 51.2 mmol) at RT. The reaction mass was heated under nitrogen atmosphere at 95 °C for 20 h. The progress of reaction was monitored by ELSD / TLC (SM was consumed). Reaction mass was cooled to RT and concentrated under reduced pressure to get 5-[bis(2-hydroxydecyl)amino]valeric acid [5] (8.0 g, 85.06 % Yield) 20 as a white semi solid, which was used for next step without further purification. Result: [000387] ELSD analysis: Purity 78.24.34 %, Calculated C25H51NO4 = 429.38, Observed = 430.35 (m / z, M+H+).25Intermediate [6]:150[000388] To a stirred solution of 5-[bis(2-hydroxydecyl)amino]valeric acid [5] (7.3 g, 17 mmol) in dichloromethane (100 mL) was added 1H-imidazole (18.5 g, 272 mmol) and (tert- butyl)(chloro)bis(methyl)silane (25.6 g, 170 mmol) at 0 °C .The resulting mixture was stirred 5 at room temperature for 16 h. The progress of reaction was monitored by TLC. After completion of reaction, reaction mixture was diluted with dichloromethane (200 mL) and washed with water and brine solution. The organic layer was dried over anhydrous Na2SO4and concentrated. The crude residue was purified by flash column chromatography (SiO2: 0- 5 % Methanol in DCM) to obtain 5-(bis{2-[(tert-butyl)bis(methyl)siloxy]decyl}amino)valeric 10 acid [6] (5.0 g, 44.71 % Yield) as a colourless liquid . Result: [000389] ELSD analysis: Purity 99.51 %, Calculated C37H79NO4Si2= 657.55, Observed = 658.45 (m / z, M+H+). 15 Intermediate [7]:[000390] To a stirred solution of 5-(bis{2-[(tert- butyl)bis(methyl)siloxy]decyl}amino)valeric acid [6] (2.8 g, 4.25 mmol) in dichloromethane 20 (40.0 mL) and dimethylformamide (10.0 mL), was added N,N-dimethyl-4-pyridylamine (1.56 g, 12.8 mmol) and EDC.HCl (2.45 g, 12.8 mmol). The reaction mixture was stirred for 15 min at RT and then added 1,3-diamino-2-methyl-2-propanol [2] (220 mg, 2.12 mmol) at room temperature. The reaction mixture was stirred at room temperature for 16 hours. The progress of reaction was monitored by ELSD / TLC. After completion of the reaction, the 25 reaction mixture was diluted with ice cold water and extracted with ethyl acetate (3x100 mL). The organic layer was dried with Na2SO4, filtered and concentrated. The crude was purified by flash column chromatography (SiO2: 10-20% EtOAc in heptane) to obtain N-{3-[5-(bis{2- [(tert-butyl)bis(methyl)siloxy]decyl}amino) valerylamino]-2-hydroxy-2-methylpropyl}5-(bis{2-151 [(tert-butyl)bis(methyl)siloxy]decyl} amino)valeramide [7] (0.4 g, 13.6 % Yield) as a colourless sticky liquid. Result: [000391] ELSD analysis: Purity 95.0 %, Calculated C78H166N4O7Si4 = 1383.18, 5 Observed = 1384.15 (m / z, M+H+). Compound 3:[000392] To a stirred solution of N-{3-[5-(bis{2-[(tert-butyl)bis(methyl)siloxy]decyl} 10 amino) valerylamino]-2-hydroxy-2-methylpropyl}5-(bis{2-[(tert-butyl)bis(methyl)siloxy] decyl} amino)valeramide [7] (0.3 g, 217 µmol) in tetrahydrofuran (3.0 mL) was added hydrogen fluoride pyridine (586 µL, 6.5 mmol) at 0 °C under inert atmosphere. The resultant reaction mass was allowed to stir at RT for 16 h. The progress of reaction was monitored by TLC. After completion of reaction, reaction mixture was quench by saturated sodium bicarbonate 15 solution up to pH 8 and extracted with ethyl acetate (3x20 mL). The organic layer was dried over anhydride sodium sulphate, filtered and concentrated under reduced pressure to get crude compound. The crude was purified by flash column chromatography (SiO2: 0-5 % MeOH in DCM) to obtain N-(3-{5-[bis(2-hydroxydecyl)amino]valerylamino}-2-hydroxy-2- methylpropyl)5-[bis(2-hydroxydecyl) amino]valeramide (110 mg, 54.75 % Yield) as a pale 20 yellow liquid . Result: [000393]1H NMR (400 MHz, CDCl3 3.30 (m, 2H), 3.29-2.93 (m, 10H), 2.92-2.78 (m, 2H), 2.48-2.23 (m, 4H), 1.88-1.73 (m, 6H), 1.67-1.57 (m, 2H), 1.54-1.14 (m, 62H), 0.89-0.86 (t, J = 6.8 Hz, 12H). 25 [000394] ELSD analysis: Purity 97.39 %, Calculated C54H110N4O7= 926.84, Observed = 927.80 (m / z, M+H+). Example 4: Synthesis of Compound 4ı52Intermediate [2]:153[000395] In a 100 ml pressure vessel, a mixture of 2-(chloromethyl)-2-methyloxirane [1] (1.0 g, 9.39 mmol) and ammonium hydroxide (10 mL) (25%) was stirred at room temperature for 48 hours. After completion (monitored by TLC), the reaction mixture was 5 concentrated to remove the excess ammonia to obtain 1,3-diamino-2-methyl-2-propanol [2] (0.8 g crude), which was forward to the next step without further purification. Result: [000396]1H NMR (400 MHz, DMSO-d6 (s, 3H). 10 Intermediate [5]:[000397] To a stirred solution of 5-aminovaleric acid [3] (2.0 g, 17.1 mmol) in methanol (200 mL) were added N-ethylbis(isopropyl)amine (9.32 mL, 51.2 mmol) and 2-decyloxirane 15 [4] (9.44 mL, 42.7 mmol) at RT. The reaction mixture was heated at 90 °C for 16 h. The progress of reaction was monitor by TLC / ELSD. After completion of reaction, reaction mixture was concentrated under reduce pressure to get crude compound. The 5-[bis(2- hydroxydodecyl)amino]valeric acid [5] (11.4 g crude) as a greenish liquid. The compound was used for next step without further purification. 20 Result: [000398] ELSD analysis: Purity 53.29 %, Calculated C29H59NO4= 485.44, Observed = 486.40 (m / z, M+H+). Intermediate [6]:154[000399] To a stirred solution of 2-hydroxydodecyl 5-[bis(2- hydroxydodecyl)amino]valerate [5] (11.4 g, 17.1 mmol) in dichloromethane (200 mL), were added (tert-butyl)(chloro)bis(methyl)silane (25.7 g, 171 mmol) and imidazole (18.6 g, 273 5 mmol) in inert atmosphere at RT. The reaction mixture was stirred at RT for 16 h. The progress of reaction was monitored with TLC. The reaction quenched with ice cold water and extracted with DCM (3x200 mL). The organic layer was dried over Na2SO4, concentrated under reduced pressure to get crude compound. The crude was taken in methanol (100 mL), water (50 mL) and added lithium hydroxide monohydrate (2.55 g, 5 eq., 60.7 mmol). The 10 resulting mixture was stirred at RT for 16 h. The methanol was evaporated; solution was acidified by using sat. citric acid solution up to pH 5 and extracted with EtOAc. The organic layer was washed with brine and dried over Na2SO4, concentrated under vacuum to get crude, which was purified by flash column chromatography (SiO2: 0-30 % EtOAc-Heptane) to obtain 5-(bis{2-[(tert-butyl)bis(methyl)siloxy]dodecyl}amino) valeric acid [6] (6.0 g, 50.0 % 15 Yield) as pale yellow liquid. Result: [000400] ELSD analysis: Purity 93.34 %, Calculated C41H87NO4Si2= 713.62, Observed = 714.70 (m / z, M+H+). 20 Intermediate [7]:[000401] To a stirred solution of 5-(bis{2-[(tert-butyl)bis (methyl)siloxy]dodecyl}amino)valeric acid [6] (2.33 g, 3.26 mmol) in dichloromethane (35.0 mL) and dimethylformamide (5.0 mL) was added 2-methyl-2,6,8-triaza-6,7-decadiene- 25 hydrogen chloride (1 / 1) (939 mg, 4.9 mmol), N,N-dimethyl-4-pyridylamine (598 mg, 4.9 mmol). The reaction mixture was stirred for 15 min at RT and added 1,3-diamino-2-methyl-2- propanol (170 mg, 1.63 mmol). The reaction mixture was stirred at RT for 16 hr. The155 progress of reaction was monitored by TLC and ELSD. The reaction mass was quenched with water and extracted with DCM (3x35 mL). The organic layer was dried over sodium sulphate, concentrated under reduced pressure to get crude. The crude was purified over silica using 0-30% ethyl acetate in hexane to give desired product as N-{3-[5-(bis{2-[(tert- 5 butyl)bis(methyl)siloxy]dodecyl}amino) valerylamino]-2-hydroxy-2-methyl propyl}5-(bis{2- [(tert-butyl)bis(methyl)siloxy]dodecyl} amino)valeramide [7] (0.7 g, 28.69 % Yield) as an off white liquid. Result: [000402] ELSD analysis: Purity 96.11 %, Calculated C86H182N4O7Si4= 1495.31, 10 Observed = 1496.35 (m / z, M+H+). Compound 4:[000403] To stirred a solution of N-{3-[5-(bis{2-[(tert-butyl)bis(methyl)siloxy] 15 dodecyl}amino) valerylamino]-2-hydroxy-2-methylpropyl}5-(bis{2-[(tert-butyl)bis(methyl) siloxy]dodecyl} amino)valeramide [7] (650 mg, 434 µmol in tetrahydrofuran (7.0 mL) was added hydrogen fluoride pyridine (1.17 mL, 13 mmol) dropwise at cooling condition under nitrogen atmosphere. The reaction mixture was stirred for 16 hr at RT. The progress of reaction was monitored by TLC and ELSD. The reaction mass quenched by saturated 20 sodium bicarbonate and extracted with ethyl acetate (3x25 mL). The organic layer was dried over sodium sulphate, concentrated under reduced pressure to get crude. The crude was soluble in pentane and wash by ACN, pentane layer was concentrated under reduced pressure to give desired product 1,5-bis({5-[bis(2-hydroxydodecyl)amino]pentyl}) 3-hydroxy- 3-methylpentanedioate (0.290 g, 64.23 % Yield) as a pale yellow liquid. 25 Result: [000404]1H NMR (400 MHz, CDCl3 (m, 8H), 2.69-2.57 (m, 4H), 2.52-2.34 (m, 4H), 2.33-2.19 (m, 6H), 1.83-1.63 (m, 4H), 1.62- 1.28 (m, 80H), 1.15 (s, 3H), 0.89-0.80 (t, J = 7.2 Hz, 12H).156 [000405] ELSD analysis: Purity 99.59 %, Calculated C62H126N4O7= 1038.96, Observed = 1039.95 (m / z, M+H+). Example 5: Synthesis of Compound 5158 Intermediate [3]:[000406] To a stirred solution of tert-butyl N-(3-aminopropyl)carbamate [1] (20 g, 115 5 mmol) and 2-decyloxirane [2] (46.5 g, 253 mmol) in isopropanol (400 mL) was added ethylbis(propan-2-yl)amine (40 mL, 230 mmol) was added at room temperature. The reaction mixture was stirred at 90 °C for 16 h. The progress of reaction was monitored by ELSD / TLC. After completion, reaction mixture was cool to room temperature and concentrated under reduced pressure get crude. The crude was purified by flash column10 chromatography (SiO2: 0-5 % MeOH / DCM) to obtain tert-butyl N-{3-[bis(2- hydroxydodecyl)amino]propyl}carbamate [3] (53 g, 82.05% Yield) as colorless liquid. Results: [000407] ELSD analysis: Purity 99.98 %, Calculated C32H66N2O4= 542.50, Observed = 543.50 (m / z, M+H+). 15 Intermediate [4]:[000408] To a stirred solution of tert-butyl N-{3-[bis(2- hydroxydodecyl)amino]propyl}carbamate [3] (53 g, 97.6 mmol) in dichloromethane (1.0 L), 20 were added 1H-imidazole (106 g, 1.56 mol), N,N-dimethylpyridin-4-amine (11.9 g, 97.6 mmol) Followed by tert-butyl(chloro)dimethylsilane (147 g, 976 mmol) was added at room temperature, allowed to stir RT for 16 h. The progress of reaction was monitored by ELSD / TLC. After completion, reaction was quenched with ice cold water and washed with brine solution. The organic layer was dried over sodium sulphate, evaporated under reduced25 pressure to get crude. The crude was purified by flash column chromatography (SiO2:10- 20% EtOAc in Hexane) to afford tert-butyl N-{3-[5,9-bis(decyl)-2,2,3,3,11,11,12,12- octamethyl-4,10-dioxa-7-aza-3,11-disilatridecan-7-yl]propyl}carbamate [4] (68 g, 90.29 % Yield) as colorless liquid. Results:159 [000409] ELSD analysis: Purity 99.94 %, Calculated C44H94N2O4Si2 = 770.68, Observed = 771.50 (m / z, M+H+). Intermediate [5]: 5[000410] To a stirred solution of 3-(bis{2-[(tert- butyl)bis(methyl)siloxy]dodecyl}amino)propylamino-tert-butylformylate [4] (1.5 g, 1.94 mmol) 10 in dichloromethane (10 mL), was added trifluoroacetic acid (2.23 mL, 29.2 mmol) at 0 °C, allow to stir at room temperature a for 3 h. The progress of reaction was monitored by ELSD / TLC. After completion, reaction mass was quenched with saturated solution of sodium bicarbonate (make pH8-9) and extracted with DCM (2x25 mL). The combined organic layers were dried over anhydrous sodium sulphate and concentrated under reduced pressure to 15 obtain 3-(bis{2-[(tert-butyl)bis(methyl) siloxy]dodecyl}amino)-1-propanamine [5] (1.3 g 0.99.59 % Yield) as pale yellow liquid. Results: [000411] ELSD analysis: Purity 99.26 %, Calculated C39H86N2O2Si2 = 670.62, Observed = 671.45 (m / z, M+H+). 20 Intermediate [7]:[000412] To stirred solution of 3-(bis{2-[(tert-butyl)bis(methyl)siloxy]dodecyl}amino)-1- 25 propanamine [5] (1.3 g, 1.94 mmol) in dichloromethane (15 mL), add triethylamine (405 µL, 2.9 mmol) followed by the addition of di(pyridin-2-yl) carbonate

[0010] (628 mg, 2.9 mmol), allow to stirred reaction at RT for 16 h. The progress of reaction was monitored by ELSD / TLC. After completion, reaction mass of pyridin-2-yl (3-(bis(2-((tert-160 butyldimethylsilyl)oxy) dodecyl)amino)propyl)carbamate [7] used as it is for next step without further purification. Results: [000413] ELSD analysis: Purity 99.78 %, Calculated C45H89N3O4Si2 = 791.64, 5 Observed = 792.35 (m / z, M+H+).[000414] To a stirred solution of pyridin-2-yl (3-(bis(2-((tert- 10 butyldimethylsilyl)oxy)dodecyl) amino)propyl)carbamate [7] (1.5 g, 1.89 mmol) in dichloromethane (25 mL), were add triethylamine (396 µL, 2.84 mmol) followed by of 3- (bis(2-((tert-butyldimethylsilyl)oxy) dodecyl)amino)propyl L-phenylalaninate

[0015] (1.7 g, 2.07 mmol) in inert atmosphere, allow to stir at room temperature for 16 h. The progress of reaction was monitored by ELSD / TLC. After completion, reaction mass was evaporated15under reduced pressure to get crude. The crude was purified by flash column chromatography (SiO2: 0-15% EtOAc / Heptane) to obtain 3-(bis(2-((tert- butyldimethylsilyl)oxy)dodecyl)amino)propyl ((3-(bis(2-((tert-butyldimethylsilyl)oxy) dodecyl)amino)propyl)carbamoyl)-L-phenylalaninate

[0016] (1.4 g 48.75 % Yield) as pale yellow liquid. 20 Results: [000415] ELSD analysis: Purity 99.75 %, Calculated C88H178N4O7Si4= 1515.28, Observed = 1515.70 (m / z, M+H+). Compound 5:161Compound 5 [000416] To stirred solution of 3-(bis(2-((tert- butyldimethylsilyl)oxy)dodecyl)amino)propyl ((3-(bis(2-((tert- butyldimethylsilyl)oxy)dodecyl)amino)propyl)carbamoyl)-L-phenylalaninate

[0012] (0.7 g, 462 5 µmol) in tetrahydrofuran (7 mL, 86 mmol) under nitrogen atmosphere added hydrogen fluoride pyridine (1.6 g, 16.2 mmol) drop wise at 0 °C, and allow to stir at RT for 16 h. The progress of reaction was monitored by ELSD / TLC. After completion, reaction mass was diluted with diethyl ether (50 mL) and washed with ice cold water (25 mL), saturated sodium bicarbonate (15 mL), Milli Q water (2x10 mL). The organic layer was collected, dried over10 sodium sulphate and evaporate under reduced pressure to obtain 3-(bis(2- hydroxydodecyl)amino)propyl ((3-(bis(2-hydroxydodecyl)amino)propyl)carbamoyl)-L- phenylalaninate (0.3 g, 61.34 % Yield) as pale yellow liquid. Results: [000417]115 (m, 1H), 4.80 -4.60 (m, 1H), 4.37-4.21 (m, 1H), 4.02-3.91 (m, 1H), 3.78-3.57 (m, 4H), 3.56- 3.42 (m, 2H), 3.31-3.23 (m, 1H), 3.07-2.97 (m, 3H), 2.69-2.58 (m, 2H), 2.57-2.42 (m, 4H), 2.41-2.16 (m, 6H), 1.76-1.65 (m, 3H), 1.61-1.58 (m, 1H), 1.43-1.22 (m, 72H), 0.89-0.86 (t, J = 7.2 Hz, 12H). [000418] ELSD analysis: Purity 99.41 %, Calculated C64H122N7O7 = 1058.93, Observed 20 = 1060.0 (m / z, M+H+). 6: Synthesis of Compound 6ı62163 Intermediate

[0017] :[000419] To a stirred solution of pyridin-2-yl (3-(bis(2-((tert- butyldimethylsilyl)oxy)dodecyl) amino)propyl)carbamate [9] (1.5 g, 1.89 mmol) in 5 dichloromethane (35 mL), were added triethylamine (396 µL, 2.84 mmol) followed by 3- (bis{2-[(tert-butyl)bis(methyl)siloxy] dodecyl}amino)propyl (S)-2-amino-4-phenylbutyrate

[0016] (1.58 g, 1.89 mmol) in inert atmosphere. Allow the reaction mixture to stir at room temperature for 16 h. The progress of reaction was monitored by ELSD / TLC. After completion, reaction mass was evaporated under reduced pressure to get crude. The crude10 was purified by flash column chromatography (SiO2: 0-15% EtOAc / Heptane) to get 3-(bis{2- [(tert-butyl)bis(methyl)siloxy]dodecyl}amino)propyl (S)-2-{3-[3-(bis{2-[(tert- butyl)bis(methyl)siloxy]dodecyl}amino)propyl]ureido}-4-phenylbutyrate

[0017] (1.4 gm, 48.31% Yield) as pale yellow liquid. Results: 15 [000420] ELSD analysis: Purity 98.88 %, Calculated C89H180N4O7Si4= 1529.29, Observed = 1529.75 (m / z, M+H+). Compound 6:Compound 6164 [000421] To a stirred solution of 3-(bis{2-[(tert- butyl)bis(methyl)siloxy]dodecyl}amino)propyl (S)-2-{3-[3-(bis{2-[(tert- butyl)bis(methyl)siloxy]dodecyl}amino)propyl]ureido}-4...

Claims

264 CLAIMS 1. A cationic lipid having a structure according to Formula (I):Formula (I), 5 or a pharmaceutically acceptable salt thereof, wherein: R1is selected from hydrogen, or optionally substituted (C1-C6)alkyl; R2is selected from -OH, -NH2, optionally substituted (C1-C6)alkyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted (C1-C3)alkylene- 10 optionally substituted aryl, or optionally substituted (C1-C3)alkylene-optionally substituted heteroaryl; b and c are integers that are each independently selected from 0, 1, 2, 3, or 4; a and d are integers that are each independently selected from 1, 2, 3, 4, 5 or 6; each Y1is independently selected from hydrogen or -OH; 15 each R4is independently selected from hydrogen or optionally substituted (C1- C6)alkyl. R3A, R3B, R3C, and R3Dare each independently selected from optionally substituted (C1-C25)alkyl, optionally substituted (C2-C25)alkenyl, or -W1-X1; each W1is independently selected from a covalent bond, optionally substituted (C1- 20 C10)alkylene or optionally substituted (C2-C10)alkenylene; and each X1is independently selected from -(*C=O)-O-optionally substituted (C3-C25)alkyl, -(*C=O)-O-optionally substituted (C3-C25)alkenyl, -*O-(C=O)-optionally substituted (C3-C25)alkyl, or -*O-(C=O)-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y1)- when W1is a covalent bond. 25 2. A cationic lipid having a structure according to Formula (II):265Formula (II) or a pharmaceutically acceptable salt thereof, wherein: 5 e and f are integers that are each independently selected from 1, 2, 3, 4, 5 or 6; each Y2is independently selected from hydrogen or -OH; R6is selected from hydrogen or optionally substituted (C1-C6)alkyl; R7is selected from optionally substituted (C1-C6)alkylene-R8or R8; R8is selected from optionally substituted aryl, optionally substituted heteroaryl. 10 R5A, R5B, R5C, and R5Dare each independently selected from optionally substituted (C1-C25)alkyl, optionally substituted (C2-C25)alkenyl, or -W1-X1; each W1is independently selected from a covalent bond, optionally substituted (C1- C10)alkylene or optionally substituted (C2-C10)alkenylene; and each X1is independently selected from -(*C=O)-O-optionally substituted (C3-C25)alkyl, 15 -(*C=O)-O-optionally substituted (C3-C25)alkenyl, -*O-(C=O)-optionally substituted (C3-C25)alkyl, or -*O-(C=O)-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y2)- when W1is a covalent bond.

3. A cationic lipid having a structure according to Formula (III):266Formula (III) or a pharmaceutically acceptable salt thereof, wherein: 5 h and i are integers that are each independently selected from 1, 2, 3 or 4; g and j are integers that are each independently selected from 1, 2, 3, 4, 5 or 6; k is an integer selected from 1, 2, 3, 4, 5, or 6; m is an integer selected from 0, 1, 2, 3, 4, 5, or 6; each Y3is independently selected from hydrogen or -OH; 10 X2is selected from H, NH2 and F; R10is selected from an optionally substituted aryl, optionally substituted heteroaryl, optionally substituted (C1-C25)alkyl or optionally substituted (C2-C25)alkenyl; R9A, R9B, R9C, and R9Dare each independently selected from optionally substituted (C1-C25)alkyl, optionally substituted (C2-C25)alkenyl, or -W1-X1;15each W1is independently selected from a covalent bond, optionally substituted (C1- C10)alkylene or optionally substituted (C2-C10)alkenylene; and each X1is independently selected from -(*C=O)-O-optionally substituted (C3-C25)alkyl, -(*C=O)-O-optionally substituted (C3-C25)alkenyl, -*O-(C=O)-optionally substituted (C3-C25)alkyl, or -*O-(C=O)-optionally substituted (C3-C25)alkenyl, wherein the atom marked 20 with a * is connected to W1or -CH(Y3)- when W1is a covalent bond.

4. A cationic lipid having a structure according to Formula (IV):267Formula (IV) wherein: p and q are integers that are each independently selected from 1, 2, 3, 4, 5 or 6; 5 each Y4is independently selected from hydrogen or -OH; R11is selected from hydrogen or optionally substituted (C1-C6)alkyl; X3is selected from a covalent bond, -O-, or -N(R13)-; R13is selected from hydrogen or optionally substituted (C1-C6)alkyl; R12A, R12B, R12C, and R12Dare each independently selected from optionally substituted 10 (C1-C25)alkyl, optionally substituted (C2-C25)alkenyl, or -W1-X1; each W1is independently selected from a covalent bond, optionally substituted (C1- C10)alkylene or optionally substituted (C2-C10)alkenylene; and each X1is independently selected from -(*C=O)-O-optionally substituted (C3-C25)alkyl, -(*C=O)-O-optionally substituted (C3-C25)alkenyl, -*O-(C=O)-optionally substituted15(C3-C25)alkyl, or -*O-(C=O)-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y4)- when W1is a covalent bond.

5. A cationic lipid having a structure according to Formula (V): 20268 Formula (V) or a pharmaceutically acceptable salt thereof, wherein: r and s are integers that are each independently selected from 1, 2, 3, 4, 5 or 6; 5 each Y5is independently selected from hydrogen or -OH; R15is optionally substituted (C1-C3)alkylene-optionally substituted bicyclic heteroaryl; R16is hydrogen; R14A, R14B, R14C, and R14Dare each independently selected from optionally substituted (C5-C25)alkyl, optionally substituted (C5-C25)alkenyl, or -W1-X1; 10 each W1is independently selected from a covalent bond, optionally substituted (C1- C10)alkylene or optionally substituted (C2-C10)alkenylene; and each X1is independently selected from -(*C=O)-O-optionally substituted (C3-C25)alkyl, -(*C=O)-O-optionally substituted (C3-C25)alkenyl, -*O-(C=O)-optionally substituted (C3-C25)alkyl, or -*O-(C=O)-optionally substituted (C3-C25)alkenyl, wherein the 15 atom marked with a * is connected to W1or -CH(Y5)- when W1is a covalent bond.

6. A cationic lipid having a structure according to Formula (VI):Formula (VI) 20 or a pharmaceutically acceptable salt thereof, wherein: t and u are integers that are each independently selected from 1, 2, 3, 4, 5 or 6; each Y6is independently selected from hydrogen or -OH; R19is selected from optionally substituted (C1-C3)alkylene-optionally substituted 25 thiazolyl and optionally substituted (C1-C3)alkylene-substituted phenyl, wherein the phenyl is substituted with one or more halogen atoms (e.g. -F); R18A, R18B, R18C, and R18Dare each independently selected from optionally substituted (C5-C25)alkyl, optionally substituted (C5-C25)alkenyl, or -W1-X1;269 each W1is independently selected from a covalent bond, optionally substituted (C1- C10)alkylene or optionally substituted (C2-C10)alkenylene; and each X1is independently selected from -(*C=O)-O-optionally substituted (C3-C25)alkyl, -(*C=O)-O-optionally substituted (C3-C25)alkenyl, -*O-(C=O)-optionally 5 substituted (C3-C25)alkyl, or -*O-(C=O)-optionally substituted (C3-C25)alkenyl, wherein the atom marked with a * is connected to W1or -CH(Y6)- when W1is a covalent bond.

7. A compound selected from those listed in (a) Table A and Table B, or a pharmaceutically acceptable salt thereof; or 10 (b) Table A, Table B and Table C, or a pharmaceutically acceptable salt thereof.

8. A composition comprising the cationic lipid of any one of the preceding claims andfurther comprising (i) one or more non-cationic lipids, 15 (ii) one or more cholesterol-based lipids, and (iii) one or more PEG-modified lipids.

9. The composition of claim 8, wherein the composition is a lipid nanoparticle, optionallya liposome. 20 10. The composition of claim 9, wherein the lipid nanoparticle encapsulates a nucleic acid, optionally an mRNA encoding a peptide or protein.

11. The composition of claim 9 or 10, wherein the lipid nanoparticle encapsulates an 25 mRNA encoding a peptide or protein.

12. The composition of claim 10 or 11 for use in a vaccine.

13. The composition of any one of claims 10 or 11 for use in therapy. 30 14. The composition of claim 11 for use in a method of treating or preventing a disease amenable to treatment or prevention by the peptide or protein encoded by the mRNA, optionally wherein the disease is (a) a protein deficiency, optionally wherein the protein deficiency affects the liver, lung, brain or muscle, (b) an autoimmune disease, (c) an 35 infectious disease, or (d) cancer.270 15. The composition for use according to any one of claims 12-14, wherein the composition is administered intranasally, intravenously, intrathecally or intramuscularly, or by pulmonary delivery, optionally through nebulization. 5 16. A method for treating or preventing a disease wherein said method comprises administering to a subject in need thereof the composition of claim 11 and wherein the disease is amenable to treatment or prevention by the peptide or protein encoded by the mRNA, optionally wherein the disease is (a) a protein deficiency, optionally wherein the protein deficiency affects the liver, lung, brain or muscle, (b) an autoimmune disease, (c) an 10 infectious disease, or (d) cancer.

17. The method of claim 16, wherein the composition is administered intranasally, intravenously, intrathecally or intramuscularly, or by pulmonary delivery, optionally through nebulization. 15

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