303 results about "Cycloaddition" patented technology

The invention discloses a preparation method and application of a catalyst based on pyridine ionic liquid, and belongs to the technical field of catalyst preparation. According to the invention, a hydrolysis reaction of a silane coupling agent is utilized to prepare a silicon oxide nanotube containing a pyridine unit, and then a quaternization reaction is carried out to obtain the catalyst based on the pyridine ionic liquid. The catalyst has a high specific surface area and a rich pore channel structure, exposure of active sites and contact of the active sites and reactants are facilitated, and the catalytic rate is increased. Meanwhile, the silicon oxide nanotube contains hydroxyl, and can cooperate with a pyridine ionic liquid site to catalyze a carbon dioxide cycloaddition reaction. The obtained catalyst can catalyze the reaction of carbon dioxide and an epoxy compound to prepare cyclic carbonate under solvent-free and metal-free conditions, and the catalyst is easy to recover and simple in product purification, and has a good application prospect.

The invention relates to the field of nutritional health food, and discloses a casein modified active peptide for promoting bone repair and a preparation method thereof.The structure of the active peptide sequentially comprises a bone targeting sequence with high affinity to hydroxyapatite, a casein phosphopeptide core sequence capable of chelating calcium ions, a casein phosphopeptide core sequence capable of chelating calcium ions, a casein phosphopeptide core sequence capable of chelating calcium ions, a casein phosphopeptide core sequence capable of chelating calcium ions and a casein phosphopeptide core sequence capable of chelating calcium ions from the C-terminal to the N-terminal. The digestion sequence can be specifically hydrolyzed by matrix metalloproteinase, and the alkynyl functional group is used for covalent cross-linking. The active peptide can be mixed with an azido-containing multi-arm cross-linking agent, and hydrogel can be rapidly formed under physiological conditions through cycloaddition reaction. The system can be gelated in situ and anchored to a bone defect part in a targeted manner, and is triggered by a specific enzyme in a pathological microenvironment to controllably release active peptide fragments capable of chelating calcium ions, so that the concentration of local mineral ions is adjusted, the cell living environment is improved, and an effective new way is provided for promoting bone repair.

The invention relates to a method for synthesizing cyclic carbonate by catalyzing olefin oxidative carboxylation with a difunctional ionic liquid, which comprises the following steps: in a synthesis system, adding an oxidant and an additive into olefin serving as a raw material and the difunctional ionic liquid serving as a catalyst, and then carrying out epoxidation reaction; after the reaction is finished, potassium iodide and a carboxylation reagent are added into a reaction system, then cycloaddition reaction is performed, and finally cyclic carbonate can be prepared. The bifunctional ionic liquid is used as a catalyst, so that the olefin epoxidation reaction can be catalyzed, the cycloaddition reaction of an epoxide intermediate and CO2 can also be catalyzed, and the problem that a two-step reaction catalytic system is incompatible is solved. The adopted raw materials are cheap and easy to obtain, a metal-free catalyst is used, the method has the advantages of being economical and environmentally friendly, and an alternative scheme is provided for synthesis of cyclic carbonate.

The application belongs to the field of catalytic synthesis of fine chemical products, and particularly relates to an ionic compound and a method for catalytically synthesizing cyclic carbonate. The application provides an ionic compound, which comprises an anion as shown in formula (I) or formula (II); wherein X is selected from O, S and Se, and the value of L is 0 or 1; the anion in the ionic compound has suitable nucleophilicity and leaving property, can be combined with other active positive ions or metal ions to form a catalytic system with good solubility, and is particularly suitable for being used in a cycloaddition reaction involving carbon dioxide. Meanwhile, the application further provides a catalytic method for synthesizing cyclic carbonate, which uses a catalytic system containing the ionic compound, so that cyclic carbonate can be synthesized in a solvent-free, low-halogen or halogen-free, low-catalyst-amount and mild reaction condition mode with high efficiency, high conversion rate and high chemical selectivity.

The invention relates to the technical field of organic synthesis, in particular to a method for synthesizing cyclopentane compounds through [3 + 2] cycloaddition reaction of aryl cyclopropane and olefin under the synergistic catalysis of bromide ions / visible light. The method comprises the following steps: in a nitrogen atmosphere, sequentially adding aryl cyclopropane, a benzyl malononitrile derivative, pyridine tribromide and a photocatalyst into a reaction solvent to obtain a mixture, stirring the mixture at the temperature of 40 DEG C under the irradiation of a 12W blue light LED lamp until the reaction is complete, and performing concentration and column chromatography purification to obtain the cyclopentane compound. The method has the advantages of mild reaction conditions, simple operation, simple and easily available raw materials and low cost.

The application relates to the technical field of catalysts, and discloses a limited type iodine-based homogeneous immobilized catalyst as well as a preparation method and application thereof. The catalyst comprises a carrier and iodine ions, magnesium ions and quaternary ammonium ions loaded on the carrier, wherein the molar ratio of the magnesium ions, the quaternary ammonium ions, the iodine ions and the carrier is 0.01-1:4-15:1-30:1. The limited type iodine-based homogeneous immobilized catalyst disclosed by the application enhances the electrostatic interaction between iodine ions and quaternary ammonium ions through the molecular sieve limiting effect to construct a limited type structure. The catalyst has significantly enhanced CO2 adsorption and activation capacity, can activate an epoxide compound, and accelerates the ring opening of the epoxide compound. In a cycloaddition reaction catalyzed by the catalyst under the conditions of no solvent and no auxiliary agent, the conversion rate of propylene oxide can reach more than 73%, and the propylene carbonate selectivity can reach more than 85%.

The invention belongs to the technical field of catalytic synthesis, particularly relates to a method for preparing a nitrogen-containing fused ring compound through quantum dot catalyzed [4 + 2] cycloaddition, and aims to solve the problems of limited product structure and complex reaction system in the existing synthesis method. The synthesis method disclosed by the invention comprises the following steps: in an inert atmosphere, adding 1-phenylpyrrole and fumarate as reaction raw materials, quantum dots as a photocatalyst and an organic solvent into a reaction container, carrying out [4 + 2] cycloaddition reaction under visible light irradiation, and then filtering, concentrating, separating and purifying to obtain the nitrogen-containing fused ring compound. The reaction condition is mild, and the method can be realized by irradiating the quantum dot catalyst with a visible light source at normal temperature and pressure; a reaction system is simple, strong oxidants and additives are not needed, operation steps are convenient, and atom economy is achieved.

The invention concerns homogenous antibody-conjugates with high payload loading (high DAR) obtained by site-specific conjugation to a single antibody N-glycan. The conjugates according to the invention are homogeneous, i.e. have a DAR at or close to the theoretical DAR with a narrow distribution, and do not require any genetic modification of the antibody. The invention further concerns a modular, non-genetic preparation method for such conjugates, involving three simple steps and starting from any antibody. These steps are (a) enzymatic remodeling of the glycan to give an antibody functionalized with two or four click probes per antibody, (b) strain-promoted cycloaddition with a multivalent, bifunctional reagent comprising one cyclic alkyne and at least two click probes that are not reactive towards the cyclic alkyne, and (c) inverse electron-demand Diels-Alder cycloaddition of the click probes with branched linker-drug constructs comprising one cyclic alkyne or strained alkene, connected to one or more payloads preferably connected through a cleavable linker. The resulting conjugates, with DAR6 or higher, are rapidly generated with high homogeneity and with surprising stability. In addition, HIC profiles of the resulting ADCs indicate small relative retention time and therefore show high potential in the targeting of tumour cells and / or the treatment of cancer.

The application provides a preparation method of high-purity pyromellitic dianhydride, which is prepared from 2,3-dichloromaleic anhydride as raw material, and sequentially subjected to Diels-Alder cycloaddition reaction, elimination reaction and oxidation reaction to obtain high-purity pyromellitic acid, and then subjected to dehydration treatment to obtain high-purity pyromellitic dianhydride. In the preparation method, pyromellitic acid is used as a dehydration raw material to prepare anhydride, so that intermediate acid by-products are not easy to be generated, and the product purity is improved; the dehydration reaction is promoted by adopting azeotropic distillation and separation coupling, so that the reaction yield is improved; the preparation steps are few, the reaction process is simple, the reaction condition is mild, the raw materials are economically inexpensive and easy to obtain; the catalyst or the aid used in each step does not generate harmful substances, and is green and environment-friendly.

The application discloses a low-viscosity nitrogen-modified flame-retardant and smoke-suppressing silicone oil and a preparation method thereof, relates to the technical field of modified silicone oil, and the flame-retardant and smoke-suppressing silicone oil is obtained by ring-opening addition reaction of double-end epoxy silicone oil and methyl urea. The nitrogen-containing group is introduced into the polysiloxane molecule in a reactive form by adopting the chemical modification of methyl urea on the end epoxy silicone oil, so that the flame-retardant and smoke-suppressing performance and the thermal stability of the silicone oil are improved without significantly sacrificing the material fluidity. The obtained low-viscosity nitrogen-modified flame-retardant and smoke-suppressing silicone oil still maintains a good flow state at normal temperature, and is convenient to use in the modification of high polymer materials, the blending of composite systems and subsequent processing applications.

The present invention relates to novel compounds of formula (I), optionally conjugated to peptide or protein molecules, and the synthesis thereof. The invention also relates to the use of the novel compounds for coupling reactions with linkers and other molecules. The invention also relates to the use of the novel compounds in bio-orthogonal strain promoted cycloaddition (copper-free), i.e. Click reaction. (I).

The present application relates to the technical field of organic synthesis, and particularly relates to a method for preparing (+)-crispine A by means of biological enzyme resolution. First, 6,7-dimethoxy-3,4-dihydroisoquinoline-2-oxide is subjected to 1,3-dipolar cycloaddition with allyl alcohol to obtain a first compound; then the first compound is added into a sulfonylation reagent and zinc powder to obtain a racemate second compound through a three-step continuous series reaction of primary alcohol sulfonylation, nitrogen-oxygen bond cleavage and ring formation; then the second compound is mixed with vinyl acetate and biological enzyme, and chiral resolution is carried out under the action of the biological enzyme to obtain a third compound with right-handed optical rotation and a fourth compound with left-handed optical rotation; finally, the third compound is mixed with an alkaline reagent and a sulfonylation reagent, and then secondary alcohol sulfonylation is carried out to obtain a fifth compound with right-handed optical rotation; the fifth compound is mixed with a deoxidizing reagent to carry out deoxidation reaction, and (+)-crispine A is prepared. The method is simple, green and environmentally friendly, and can be produced in large quantities.

The invention belongs to the field of roller shutter fabrics, and particularly relates to a composite self-cleaning roller shutter fabric and a preparation method thereof. The method comprises the following steps: 1) pretreating raw materials to prepare a base material; (2) carrying out structure optimization on the surface of the base material by adopting a chemical vapor deposition method to prepare an optimized base material; and (3) annealing the optimized base material at low temperature to prepare the composite self-cleaning roller shutter fabric. The transverse nanotube formed by chemical vapor deposition guides water drops to rapidly migrate in a specific direction through surface energy gradient difference, self-cleaning is realized, cycloaddition transition enables surface molecules to form a stable Si-O-Si cross-linked network, surface free energy is remarkably reduced, hydrophobic durability is enhanced, meanwhile, a polyester / polyamide base material provides flexibility, and the self-cleaning performance is improved. And through chemical bond combination with the chemical vapor deposition layer, the problem of interface stripping is avoided.

This invention discloses a brush-like peptide drug delivery system, its preparation method, and its applications, belonging to the fields of polymer chemistry and biomedicine. The method includes modifying the amino acid residues of a peptide drug with active functional groups through click or cycloaddition reactions; reacting the modified peptide drug with a polydisulfide backbone through click or cycloaddition reactions to obtain a brush-like peptide drug; and performing charge shielding and bioactivity modification on the lysine residues in the brush-like peptide drug to obtain the brush-like peptide drug delivery system. The brush-like peptide drug delivery system of this invention reduces peptide toxicity, enhances peptide targeting, improves peptide pharmacokinetics, and solves the problem of poor water solubility of some peptide drugs. It can be used in the treatment of tumors, cardiovascular diseases, neurological diseases, pathogenic bacterial or viral infections, or in the development of vaccines.

The invention discloses a chiral 1, 4-diazabicyclo [3.1. 1] heptane derivative as well as a synthesis method and application of the chiral 1, 4-diazabicyclo [3.1. 1] heptane derivative. According to the invention, a 1-azabicyclo [1.1. 0] butane derivative is taken as a raw material, under the catalytic action of a chiral iridium complex, the 1-azabicyclo [1.1. 1] butane derivative and an N-allyl carbonate derivative are subjected to [3 + 2] cycloaddition reaction, a series of chiral 1, 4-diazabicyclo [3.1. 1] heptane skeletons with diversified structures are constructed with high stereoselectivity, and the obtained product has the potential of further derivatization. The method has the advantages of easily available raw materials, mild reaction conditions, simplicity and convenience in operation, good functional group compatibility and the like.

The present invention provides an antibody-payload conjugate having a payload antibody ratio of 1. The antibody-payload conjugate has the structure (1): Formula (1) (wherein a, b, and c are each independently 0 or 1; L 1 , L 2 and L 3 is a linker; D is a payload; BM is a branching moiety; and Z is a connecting group obtainable by a cycloaddition reaction. The present invention further provides methods for preparing antibody-payload conjugates according to the invention, intermediate compounds in the preparation methods, and medical uses of antibody-payload conjugates according to the invention.

This invention relates to the field of organic synthetic chemistry, specifically to a polysubstituted furan compound and its synthetic method, wherein the method comprises... β Using ketone sulfones and olefins as starting materials, polysubstituted furans are synthesized via a [3+2] cycloaddition reaction in the presence of a copper catalyst and an oxidant. This invention employs cuprous bromide as the catalyst and di-tert-butyl peroxide (DTBP) as the oxidant, reacting in dimethyl sulfoxide solvent at 100°C–130°C for 6–24 h. This method offers advantages such as high atom and step economy, broad substrate applicability, good functional group tolerance, excellent position selectivity, and high yield, with a maximum yield reaching 84%. It is suitable for large-scale synthesis and provides a new strategy for the synthesis of furans in medicinal chemistry and materials science.

The invention discloses DNA (deoxyribonucleic acid) coupled non-natural amino acid as well as a synthesis method and application thereof. The synthesis method of the DNA coupled non-natural amino acid comprises the following steps: adding inorganic alkali and 2, 5-dibromohexane diamide into a boric acid buffer solution containing DNA coupled cysteine as shown in a general formula (I) in the specification, adding an organic phase, and reacting at 25-37 DEG C to enable the DNA coupled cysteine to be subjected to desulfurization elimination, thereby obtaining the DNA coupled non-natural amino acid. DNA coupling dehydroalanine shown as a general formula (II) in the specification is obtained; the method comprises the following steps: carrying out nucleophilic addition reaction on DNA coupled dehydroalanine and a nucleophilic reagent under an alkaline condition or carrying out dipolar cycloaddition reaction on DNA coupled dehydroalanine and 2, 5-substituted tetrazole under an ultraviolet condition to obtain the DNA coupled unnatural amino acid. By adopting the method, the integrity of the DNA chain can be effectively ensured, no by-product is generated in the reaction, and a more powerful chemical tool is provided for construction and subsequent modification of a DNA coding molecular library.

The application belongs to the technical field of photocatalytic CO2 cycloaddition reaction, and particularly relates to a preparation method of a vacancy defect layered bismuth semiconductor material and application of the vacancy defect layered bismuth semiconductor material in photocatalytic CO2 cycloaddition reaction. The material is based on a bismuth semiconductor material with a Sillen-Aurivillius structure, and a defect site is constructed by vacancy regulation of the material. Low-valence metal ions exposed by the vacancy defect can be used as Lewis acid sites to adsorb and activate epoxides, and the defect site can promote separation of photo-generated carriers, thereby enhancing surface reaction kinetics and effectively improving photocatalytic activity of the material, and finally promoting photocatalytic CO2 cycloaddition reaction performance.

The application provides a one-dimensional high-entropy alloy, a preparation method and application of the one-dimensional high-entropy alloy in CO2 ring addition reaction, and relates to the technical field of high-entropy alloys.The molar ratio of iron salt, cobalt salt, nickel salt, manganese salt, chromium salt and cerium salt in the one-dimensional high-entropy alloy is 1:1:1:1:1:1;the high-entropy alloy has a fiber structure, the fiber has a hierarchical pore structure which is interconnected, including macropores or mesopores formed by decomposition of the self-sacrificing template 1, and mesopores or micropores formed by decomposition of the self-sacrificing template 2.Through improvement of the process conditions, the one-dimensional high-entropy alloy material with a unique structure can be prepared under relatively mild conditions, so that the whole reaction process is safer and more economical, and meets the goal of green chemistry and sustainable development.Meanwhile, the one-dimensional high-entropy alloy material prepared provides a large specific surface area, fully exposes active sites, and can realize efficient and stable conversion of the carbon dioxide ring addition reaction.

This invention relates to the field of chemical synthesis technology, specifically disclosing a method for preparing vinyl ethylene carbonate. The method uses glycidyl as a starting material, first converting it to glycidaldehyde via a mild oxidation reaction with high selectivity. Then, using a cross-linked imidazole polymeric ionic liquid as a catalyst, glycidaldehyde undergoes an atom-economical cycloaddition reaction with carbon dioxide to construct a cyclic carbonate intermediate. Finally, under catalytic conditions, a condensation reaction introduces a vinyl functional group to obtain the vinyl ethylene carbonate product. This invention uses widely available, low-toxicity, and inexpensive glycidyl instead of highly toxic raw materials, and utilizes greenhouse gas carbon dioxide as a carbonyl source for resource utilization. The process route is highly atom-economical, the reaction conditions are mild, and the catalyst is easy to separate, recover, and recycle, effectively solving the prominent problems of high raw material toxicity, expensive catalysts, and difficult byproduct treatment in traditional preparation techniques.

This invention belongs to the field of organic synthesis technology and relates to a precursor of an obisec key intermediate and a method for preparing the key intermediate. The method involves a [4+2] cycloaddition reaction of 4-trifluoromethylaniline, propionaldehyde, and N-vinylformamide under the catalysis of chiral phosphoric acid, yielding the obisec key intermediate precursor with high enantioselectivity. N -((2) R 4 S )-2-ethyl-6-trifluoromethyl-1,2,3,4-tetrahydroquinoline-4-yl)formamide; subsequently, the key intermediate of obisetri can be obtained through a deprotection reaction under acidic conditions. The method provided by this invention uses a small amount of chiral catalyst and commercially available reagents to efficiently obtain the key intermediate of obisetri in just two steps. R 4 S )-2-ethyl-6-trifluoromethyl-1,2,3,4-tetrahydroquinoline-4-amine; under mild conditions without the need for chiral resolution, the utilization of starting materials is greatly improved, thereby significantly increasing the yield of the target product and the economic efficiency of the process.

The invention provides a preparation method and application of macrocyclic multi-amino porous organic aerogel, and belongs to the field of catalysts. The preparation method comprises the following steps: reacting tetraazacyclododecane with chloromethyl styrene to obtain an intermediate; and carrying out sol-gel polymerization on the intermediate, and drying to obtain the macrocyclic multi-amino porous organic aerogel. As a thermal insulation material and a heterogeneous catalyst, the macrocyclic multi-amino porous organic aerogel can be applied to thermal insulation and cycloaddition reaction of a halogenated epoxy substrate and carbon dioxide, and has the characteristics of high conversion rate and high selectivity.

The application discloses an ionic liquid polymer catalyst and a preparation method and application thereof, and relates to the field of ionic liquid polymer catalysts. The catalyst is obtained through polymerization reaction of a vinyl functionalized triphenylphosphine ligand, a vinyl functionalized triphenylphosphine ionic liquid and a metal source; wherein the vinyl functionalized triphenylphosphine ionic liquid is obtained from the vinyl functionalized triphenylphosphine ligand. The ionic liquid polymer catalyst has more excellent catalytic performance and better substrate universality, the preparation method is simple, flue gas can be directly used as a CO2 source, and the CO2 does not need to be purified, so that energy is effectively saved and the environment is protected; meanwhile, the cycloaddition reaction condition is mild, green and pollution-free; the yield of the product cyclic carbonate is as high as 99%, and the ionic liquid polymer catalyst shows good prospects for solving the problems of reactivity, good universality, difficulty in recycling of the catalyst, serious loss of active metals and ligands and other problems in a multiphase cycloaddition reaction.

The application discloses a preparation method of a catalyst based on a pyridine ionic liquid and application thereof, and belongs to the technical field of catalyst preparation. The catalyst based on the pyridine ionic liquid is prepared by utilizing the hydrolysis reaction of a silane coupling agent to obtain silica nanotubes containing a pyridine unit, and then through a quaternary ammonium reaction. The catalyst has a high specific surface area and a rich pore structure, is favorable for exposure of active sites and contact of the active sites with reactants, and improves a catalytic rate. Meanwhile, the silica nanotubes contain hydroxyl groups, can synergistically catalyze a carbon dioxide cycloaddition reaction with pyridine ionic liquid sites, and can catalyze a reaction of carbon dioxide and an epoxide compound to prepare a cyclic carbonate under a solvent-free and metal-free condition. The catalyst is easy to recycle, product purification is simple, and the catalyst has a good application prospect.

This invention provides a zinc-nickel single-atom alloy catalyst, its preparation method, and its applications. The invention relates to the field of catalyst synthesis technology. This zinc-nickel single-atom alloy catalyst has a carbon-coated structure with a porous surface. Zinc is dispersed in single-atom form on the surface of nickel particles, forming a single-atom alloy structure, and simultaneously possessing both Lewis acidic and Lewis basic sites. Through innovative material design and preparation methods, this invention successfully synthesizes a novel zinc-nickel single-atom alloy catalyst with superior performance. This catalyst cleverly combines efficient photothermal conversion, the electronic regulation characteristics of single-atom alloys, and the structural advantages of a porous carbon support. It achieves highly efficient and selective conversion of CO2 cycloaddition reactions under mild conditions, while exhibiting significant advantages in energy consumption, cost, and stability, showing promising prospects for industrial applications.

The invention relates to the technical field of information communication particularly suitable for specific application fields, and discloses a machine learning-based ionic liquid screening method for catalyzing CO2 cycloaddition reaction. The method comprises the following steps: constructing an ionic liquid three-dimensional structure database; calculating and generating a three-dimensional electrostatic potential and electron density data field through a density functional theory; voxelizing the data field into a standardized multi-channel three-dimensional tensor; utilizing a three-dimensional convolutional neural network regression model to automatically learn space electron characteristics and predict catalytic activity; and performing high-throughput virtual screening on the candidate library. Through end-to-end learning of the mapping relation between the three-dimensional electronic structure and the catalytic activity of the ionic liquid, the prediction accuracy and the screening efficiency are improved.

The application discloses a preparation method of 3,4-dihydropyran derivatives, and a reaction formula is as follows: the unactivated propenal and the weak polar olefin which are simple in structure and low in material cost are used as starting materials, the unactivated propenal and the weak polar olefin which are weak in reactivity can participate in [4+2] cycloaddition, and the 3,4-dihydropyran derivatives with high purity can be prepared; the preparation process is simple in operation, high in yield and excellent in diastereoselectivity, can effectively convert low-cost raw materials into high-value-added compounds, and provides an economic and efficient synthesis strategy for related industries.

The application discloses a kind of high-efficiency heterogeneous catalyst for CO2 ring addition preparation cyclic carbonate and its preparation method and application, belong to catalyst technical field.The high-efficiency heterogeneous catalyst is transition metal doped polyoxometalate coordination polymer, chemical general formula is C 16 H 58 M2N2Na2O 48 V 10 Wherein, M is selected from Co 2+ , Ni 2+ , Cu 2+ Or Zn 2+ Its preparation method is: sodium vanadate, transition metal acetate and bis (2-hydroxyethyl) amino (trihydroxymethyl) methane ligand are dissolved in water with pH being 1~3, stirring reaction, after filtration, crystallization is stationary, and is obtained.In the ring addition reaction of CO2 and epoxide, the catalyst and cocatalyst tetrabutylammonium bromide synergistic effect, catalytic yield can be up to 98.2%, selectivity is more than 99%, and catalytic activity still remains at 88% after recycling five times.