79 results about "Achirality" patented technology

Described herein are methods of syntheses of phosphorous atom-modified nucleic acids comprising chiral X-phosphonate moieties. The methods described herein provide backbone-modified nucleic acids in high diasteteomeric purity via an asymmetric reaction of an achiral molecule comprising a chemically stable H-phophonate moiety with a nucleoside/nucleotide.

The invention discloses a preparation method of chiral nanometer copper oxide with optical activity. The preparation method comprises the following steps of: (1) dissolving an achiral anionic surface-active agent and a chiral small molecule into water at room temperature to obtain an achiral anionic surface-active agent and chiral small molecule water solution; (2) adding inorganic copper salt to the achiral anionic surface-active agent and chiral small molecule water solution, and stirring to react for 10-60 minutes; (3) adding alkali to reaction liquid obtained from the step (2), then increasing temperature to 100-200 DEG C, and reacting for 30 minutes-6 hours; (4) after the reaction is finished, centrifugalizing or filtering the reaction liquid obtained from the step (3), and washing and drying to obtain the chiral nanometer copper oxide with the optical activity. The prepared chiral nanometer copper oxide with the optical activity shows very uniform flower-shaped appearance and shows outstanding optical activity by having chirality.

The present invention describes a composition and a method for producing mesoporous silica materials with a chiral organization. In the method, a polymerizable inorganic monomer is reacted in the presence of nanocrystalline cellulose (NCC) to give a material of inorganic solid with cellulose nanocrystallites embedded in a chiral nematic organization. The NCC can be removed to give a stable porous structure that retains the chiral organization of the NCC template. The new materials may be obtained as iridescent free-standing films with high surface area. Through control of the reaction conditions, the colour of the films can be varied across the entire visible spectrum. These are the first materials to combine mesoporosity with long-range chiral ordering that leads to photonic properties. Examples of possible applications of the materials are: lightweight reinforcement materials, low k dielectric materials, tunable reflective filters, adsorbents, stationary phases for chromatography of chiral or achiral substances, supports for catalysts (e.g., for asymmetric synthetic transformations), and as a template to generate other new porous materials (e.g., porous carbon or porous metals), preferably with chiral nematic structures.

The invention discloses an achiral side methyl alkyl terphenyl liquid crystal compound, a production method of the achiral side methyl alkyl terphenyl liquid crystal compound, a liquid crystal composition and application. The achiral side methyl alkyl terphenyl liquid crystal compound is of a molecular structure as shown in a formula (I) as shown in the specification. An achiral conformation branch end group of the compound (I) makes the compound (I) have a wide-temperature nematic phase state, and the branch end group improves the flexibility of a molecule, so that the compound (I) has a lowmelting point and large dielectric and optical anisotropy; due to a stable molecular structure of the compound (I), microwave absorption is little so that dielectric loss of a microwave device can bereduced; the compound (I) and other nematic liquid crystal compounds can be mixed to form a nematic liquid crystal material with large dielectric anisotropy and large optical anisotropy; and by applying the compound (I) into the microwave device, improvement of the phase modulation capability of the liquid crystal microwave device is facilitated, and a quality factor of the liquid crystal materialas a microwave medium is increased.

The invention relates to an N-heterocyclic carbene catalytic functionalized imine as a novel 1, 4-dipole synthon and application thereof, and belongs to the field of chemical synthesis. Under the mild reaction condition, a chiral N-heterocyclic carbene catalyst is used for catalyzing and activating aldimine, a novel aza 1, 4-dipole synthon is obtained under the oxidation condition, and the novel organic synthon can be further subjected to 4 + 2 cyclization reaction with trifluoroacetophenone, isatin and an isatin-derived imine substrate to generate a heterocyclic compound with a novel structure and a chiral quaternary carbon center. According to the method disclosed by the invention, the N-heterocyclic carbene catalyst with the same chiral configuration and an achiral thiourea catalyst are used for co-catalysis, so that three-dimensional diverse synthesis of the trifluoroacetophenone compound can be realized. The method is mild in condition and efficient in reaction and has good substrate universality, and the reported aldimine-derived 1, 4-aza dipole synthon provides an important method for synthesizing various functional nitrogen heterocyclic compounds and has the potential of being applied to industrial production.

The invention provides a preparation method and an application method of chiral-atom-free helically chiral all-cis polyphenylacetylene derivative materials. The preparation method comprises: dissolving a non-optically active poly 3,5-dihydroxymethyl-4-substituted phenylacetylene derivative in a chiral solvent to prepare a solution, replacing the chiral solvent in the solution with an achiral solvent through a membrane permeation method, and carrying out precipitation washing to prepare a series of the chiral-atom-free all-cis helical poly 3,5-dihydroxymethyl-4-substituted phenylacetylene derivative materials with helical chirality and the corresponding coating type high-performance liquid chromatography chiral stationary phase. According to the present invention, the used chiral reagent ofthe preparation method can be repeatedly used, the preparation method has characteristics of low cost and simple operation, the chiral stationary phase has good chiral splitting performance, and themethod has broad application prospects.

The invention discloses a chiral azobenzene polymer film as well as a preparation method and application thereof. A side chain-type azobenzene polymer is prepared into a film; and chiral reagent induction is carried out to obtain a chiral azobenzene polymer film. The method comprises the following steps: firstly, synthesizing an azobenzene random copolymer with hydroxyl at the tail end of a side chain through a series of organic synthesis reactions and RAFT polymerization, and carrying out detailed investigation on the molecular weight and the liquid crystal performance of the polymer by utilizing characterization means such as nuclear magnetism, GPC, DSC, POM and XRD; and preparing a polymer film in a spin-coating manner, and performing chiral induction on the polymer film by selecting chiral limonene steam to obtain an optically active polymer film. The chirality is transmitted from a chiral reagent to an achiral substance. The chiral solvent induction method provided by the invention is simple to operate, and avoids the complex synthesis steps of the chiral polymer and the use of expensive chiral reagents.

The invention discloses a method for preparing a chiral optical thin film with a porphyrin intercalation DNA and a hydrotalcite compound. The technical scheme of the invention is that the method comprises the following steps: firstly, stripping hydrotalcite nano-particles into nano-sheets serving as construction units; secondly, assembling the hydrotalcite nano-sheets with positive charges and a DNA with negative charges by using a layer-by-layer assembly technology; and finally, inserting achiral optical molecular porphyrin into a spiral cavity of the DNA to obtain a thin film material inducing chiral luminescence. A hydrotalcite matrix provides a closed and stable microenvironment for DNA molecules. Ordered packing of high-orientation and high-density DNA arrays can be realized, which is favorable for signal amplification of optical molecules. The achiral optical molecular porphyrin obtains a chiral luminescence characteristic after entering the chiral DNA spiral cavity. Therefore, the invention provides a new method for preparing a chiral optical thin film material.

The invention provides a stretchable blue-phase liquid crystal elastomer and a preparation method thereof. The stretchable blue-phase liquid crystal elastomer is prepared from the following raw materials: achiral micromolecular liquid crystal, a photopolymerizable monomer, a chiral material, a photoinitiator and a click reaction crosslinking monomer. In the preparation method, liquid crystal molecules can be induced to be self-assembled to construct a blue-phase liquid crystal structure in a click chemical reaction process. The blue-phase liquid crystal elastomer has a synergistic response to deformation and color change and has good mechanical ductility, and the mechanically reversible reflection color of the elastomer can be flexibly adjusted in almost the whole visible light wave band and can be stretched to two times or more of the original length.

The invention discloses a method for asymmetric functionalization of nickel-hydrogen catalytic olefin migration promoted by a ligand relay strategy. Under the action of a metal nickel salt, an achiral ligand, a chiral ligand, alkali, a hydrogen source, an additive and the like, olefin and various electrophilic reagents are dissolved in an organic solvent for reaction, and the chiral compound with excellent regioselectivity and enantioselectivity is obtained. According to the method, the chiral compound containing various functional groups can be efficiently synthesized, the product has high enantioselectivity, the raw materials are simple and easy to obtain, and operation is easy and convenient.

The invention discloses a chiral menthyl liquid crystal oligomer film and a preparation method thereof, the chiral menthyl liquid crystal oligomer is prepared by copolymerizing chiral menthyl liquid crystal monomers, achiral rod-like monomers and polymethyl hydrogen-containing linear siloxane in different molar ratios, the structural formula of the chiral menthyl liquid crystal oligomer is as shown in formula III, and the chiral menthyl liquid crystal oligomer film with bright color at room temperature is obtained by high-temperature quenching. The chiral menthyl liquid crystal oligomer film has high thermal stability and a wide liquid crystal interval, can retain the color of cholesteric liquid crystal at room temperature, presents bright color, and has wide application.

A device using a liquid crystal medium exhibiting an optically isotropic liquid crystal phase, particularly, a blue phase liquid crystal medium for polarized light control application, in which reduction of an effective dielectric constant in a high frequency region is suppressed. A liquid crystal composition contains achiral component T, and has a liquid crystal phase optically exhibiting isotropy, in which achiral component T contains at least one compound selected from the group of compounds represented by formula (1) as a first component, at least one compound selected from the group of compounds represented by formula (2) and formula (3) as a second component, and is used for optical switching for controlling retardation by electric field-induced birefringence.

A liquid crystal medium that has stability to heat, light and so forth, a wide temperature range of a liquid crystal phase and significantly large dielectric anisotropy to develop an optically isotropic liquid crystal phase is required. Moreover, various optical devices that can be used in a wide temperature range, and have a short response time, a large contrast ratio and a low drive voltage are required.

A liquid crystal composition contains an achiral component T containing at least one compound (1) represented by formula (1) and a chiral agent to develop an optically isotropic liquid crystal phase:

(wherein, in formula (1), R¹ is alkyl having 1 to 12 carbons, L¹, L² and L³ are each independently hydrogen, fluorine or chlorine; and Y¹ is fluorine, for example).

The invention discloses a chiral azobenzene polymer cross-linked film as well as a preparation method and application thereof. The chiral azobenzene polymer cross-linked film is a novel super-molecular chiral construction and chiral immobilization method based on an achiral side chain type azobenzene polymer film. According to the invention, limonene steam is utilized to carry out chiral inductionon a polymer film at a high temperature, and then formaldehyde steam is utilized to carry out acetalation reaction with hydroxyl in an acidic environment to realize cross-linking; and then the difference of the stability of the super-molecular chirality of the polymer film before and after crosslinking is studied under the conditions of light, heat and good solvent dissolution, and the self-repairing performance of the microcosmic spiral chirality is researched. The cross-linked film prepared by the invention has good chiral performance and excellent solvent resistance, heat resistance and self-repairing performance.

The invention provides a self-supporting blue-phase liquid crystal film. The self-supporting blue-phase liquid crystal film comprises the following components in percentage by mass: 3-7% of chiral liquid crystal, 24-93% of achiral polymerizable liquid crystal, 0-65% of achiral small molecular liquid crystal and 4-12% of non-liquid crystal cross-linking agent. The blue-phase liquid crystal film canrealize self-supporting and is not limited by a liquid crystal box, so that the application range of the blue-phase liquid crystal film is greatly expanded; the temperature range of the blue phase isnot lower than 220 DEG C, and the reflection band gap and the reflectivity can be regulated and controlled by adjusting the proportion of all the raw materials. In addition, the blue-phase liquid crystal film is simple to prepare and operate, low in cost and suitable for large-scale preparation.

The invention provides a method for preparing a moxifloxacin intermediate (S, S)-2, 8-diazabicyclo [4, 3, 0] nonane, and relates to the technical field of organic synthesis. According to the method, the azaphthalide is used as a raw material, and due to the ring structure of the azaphthalide, the other two non-corresponding chiral isomers which are not needed in chiral reduction are almost not generated; the chiral purity of the intermediate obtained through reduction is very high, resolution is not needed, and (S, S)-2, 8-diazabicyclo [4, 3, 0] nonane can be obtained directly through ammonolysis, reduction, chlorination and cyclization subsequently. According to the method provided by the invention, chiral resolution is not needed, the process is simple, the process steps are short, the cost is low, and the product is high in chiral purity and high in total yield. Furthermore, in the subsequent product salifying and refining step, carboxylic acid with a chiral structure does not need to be used for salifying, and common achiral carboxylic acid can be used for refining, so the product purity is further improved.

The invention relates to a single chiral center catalyst, a preparation method thereof and a method for catalytically synthesizing chiral alcohol compounds and chiral alpha-allyl alcohol. The single chiral center catalyst has a structure as shown in the following general formula shown in the description, wherein in the formula, Z is -S-, -N = CH- or -CH = CH-. According to the catalyst, the achiral diphosphorus ligand is adopted, and chiral elements of the diamine ligand are reserved and adjusted at the same time, so the chirality of catalyzing asymmetric reaction can be independently controlled, and the synthesis difficulty and cost of the chiral catalyst are greatly reduced; the catalyst can be used for catalyzing asymmetric transfer hydrogenation of aryl-aryl substituted ketone compounds, heterocyclic aromatic-aryl substituted ketone compounds and heterocyclic aromatic-heterocyclic aryl substituted ketone compounds, preparing chiral secondary alcohol compounds and achieving kinetic resolution of racemic alpha-allyl alcohol compounds.

The invention discloses an achiral SCS type pincer-like compound and a palladium complex thereof. Chemical formulas of the achiral SCS type pincer-like compound (II) and the palladium complex (I) of the achiral SCS type pincer-like compound (II) are respectively shown in the following general formulas (II) and (I). The palladium complex (I) (wherein X represents -Cl, and R and R1 represent a hydrogen atom or an alkyl group having 1-4 carbon atoms) is synthesized by a coordination reaction between the compound (II) and a divalent palladium salt. The palladium complex (I) (wherein X is a group selected from -Br, -I,- OAc, -OTf, -BF4 and -SbF6) is synthesized by an anion exchange reaction of the palladium complex (I) in which X represents -Cl. The palladium complex (I) can be used as a catalyst to be applied to a transfer hydrogenation reaction, a used solvent does not need to be treated, the reaction undergoes in air, and the catalytic effect is good.

The invention discloses a preparation method of a chiral 4-alkyl-pyrrole-3-formic acid compound, which utilizes the spatial effect of an Evans chiral prothetic group to realize asymmetric hydrogenation reduction through metal catalytic hydrogenation to obtain a chiral target compound. Compared with the prior art, the method has the advantages that the achiral pyrrolidine-3-formic acid with low price can be used as a starting material, so that the production cost is reduced. The use of dangerous reagents such as nitromethane and sodium borohydride is avoided, and the safety of the production process is improved.

The invention provides a preparation method of chiral polydiacetylene. According to the preparation method, cysteine modified metal nanometer particles are added onto the surface of a diacetylene molecular film drop by drop, and then achiral ultraviolet irradiation is carried out so as to obtain chiral polydiacetylene. It is found in results that in polymerization process, diyne molecules possess adsorption difference on left-hand circularly polarized light and right-hand circularly polarized light, dropwise adding of the cysteine modified metal nanometer particles is capable of converting achiral ultraviolet light into a chiral light source, and inducing monomer polymerization, so that helical structures of polydiacetylene are formed. It is found through study on the influences of two single wavelength achiral ultraviolet lights at 254 and 313nm on polydiacetylene optical activity that, in CD signals, the directions of continuous double peaks are completely opposite. The preparation method can be combined with conventional ink-jet printing technology and lithography technology to realize construction of chiral patterns, realize control on difference micro-area chirality; and at the same time, the chirality of the obtained polydiacetylene is high, and the polydiacetylene can be used in identification of chiral small molecule configurations.