437 results about "Regioselectivity" patented technology

The invention discloses a streptomyces-derived cytochrome P450 enzyme mutant and an application of the streptomyces-derived cytochrome P450 enzyme mutant in synthesis of ursodesoxycholic acid. The cytochrome P450 enzyme mutant is obtained by carrying out single mutation or multiple mutation on the 181st site, the 192nd site, the 249th site or the 288th site of an amino acid sequence shown in SEQ ID NO.2. The cytochrome P450 enzyme mutant has high activity and regioselectivity, low-cost lithocholic acid is used as a substrate, efficient cytochrome P450 enzyme is used for hydroxylating the 7beta site of the lithocholic acid, ursodesoxycholic acid is synthesized in one step, the industrial production cost is greatly reduced, and the cytochrome P450 enzyme mutant has good application prospects in industrial production of ursodesoxycholic acid.

The invention discloses a method for efficient conversion and utilization of mogroside. According to the method, mogroside V is converted through fermentation of candida parapsilosis L7, and siamenoside I is directionally synthesized. According to the invention, Candida parapsiloides L7 is utilized for fermentation conversion, and beta-1, 6-glucosidic bonds in glucose branched chains connected with C3-site hydroxyl of a mogroside V structure parent nucleus can be directionally hydrolyzed with high regioselectivity (the beta-1, 6-glucosidic bonds on glucose branched chains connected with C24-site hydroxyl are hardly hydrolyzed), so that one molecule of glucose is removed, and siamenoside I is obtained. The siamenoside I provided by the invention can be efficiently prepared, and the maximum molar yield of the siamenoside I can reach 87.40%. The siamenoside I has more obvious selective hydrolysis characteristic, higher space time yield of the siamenoside I, no cytotoxicity of the siamenoside I and better anti-inflammatory and antioxidant activity, provides a new drug choice for diseases such as inflammation and the like, and provides technical support for development of high-valued products of mogroside.

According to the invention, glycosyl transferase UGTBL1 derived from Bacillus licheniformis ZSP01 is taken as a research object, AlphaFold 2 is used for modeling, molecular docking, molecular dynamics simulation and other technologies, amino acid in an active pocket region of glycosyl transferase is analyzed, amino acid in a substrate channel is analyzed by software CAVER3.0, site-directed mutagenesis is carried out, and the glycosyl transferase UGTBL1 is obtained. The regioselectivity and the activity of the mutant for catalytically synthesizing the icariside D2 glycosyltransferase are improved.

The invention relates to a method for synthesizing tetrasubstituted ‑1,3‑enedicarboxylic acid, and discloses a method for synthesizing tetrasubstituted ‑1,3‑enedicarboxylic acid. The method comprises the following steps: using 1,3‑enyne and iodide as raw materials, potassium formate as a formate source, DABCO as a hydrogen transfer catalyst, Ir(bpy)2(dtbpy)PF6 as a photocatalyst, and cesium carbonate as a base, introducing CO2 under normal pressure, and obtaining an enedicarboxylic acid compound with an excellent to good yield under room temperature and visible light irradiation for 24 hours. The method has mild reaction conditions, good regioselectivity, and good functional group tolerance, and makes up for many deficiencies of the prior art.

The invention discloses a method for synthesizing degradable polyethylene through copolymerization of conjugated lactone and cycloolefin. The preparation method comprises the following steps: catalyzing ring-opening metathesis polymerization of alpha, beta-unsaturated lactone and a cycloolefin monomer by using a Grubbs catalyst, hydrogenating the obtained copolymer to prepare a series of polyethylene-like materials with different densities introduced into ester groups in a main chain, and simultaneously retaining the thermal and mechanical properties of high-density polyethylene; after the polyethylene material is degraded and recycled through alcoholysis, polyethylene-like with high molecular weight and excellent performance can be obtained again through a polycondensation method, and the problem that an existing polyethylene material is difficult to recycle is solved. The synthesis method is simple and convenient to operate, the polymer obtained by copolymerization of conjugated lactone and cyclooctene is high in molecular weight, and ester groups in a main chain are uniformly distributed. Regioselectivity of conjugated lactone polymerization is good, and an AB type monomer obtained after alcoholysis is beneficial to polycondensation to obtain a high-molecular-weight polymer. The hydrogenated product is pure white solid powder, has few metal catalyst residues, and is expected to replace a bulk polyethylene material.

The invention relates to a synthesis method of a diunsaturated ester compound catalyzed by N-heterocyclic carbene, and belongs to the field of organic synthesis. According to the preparation method, the synergistic effect of N-heterocyclic carbene and light is utilized, gamma-oxo unsaturated aldehyde and Katritzky salt are taken as starting raw materials, the Katritzky salt generates alpha-ester free radicals through a single electron transfer process under the illumination condition, the free radicals react with a nucleophilic trienol intermediate generated through catalysis of the N-heterocyclic carbene, and the alpha-ester free radicals react with the nucleophilic trienol intermediate to generate the gamma-oxo unsaturated aldehyde. Target products are obtained with good yield and high regioselectivity, so that a series of epsilon-alkylated diunsaturated ester compounds are efficiently synthesized. The method is simple and convenient to operate, green and efficient, has the advantages of no transition metal participation, wide substrate applicability and the like, provides a new way for synthesis of the diunsaturated ester compound, and has a wide application prospect.

The invention discloses a method for electrochemical C-H deuterization of pyridine derivatives and D2O and a deuterated compound prepared by the method. The method provided by the invention comprises the following steps: under a power-on condition, a pyridine derivative, an electrolyte and D2O are subjected to an electrochemical reaction in a solvent, so that a C-H bond in the pyridine derivative is converted into a C-D bond. The invention provides a method for carrying out C4 selective C-H deuterization reaction on a simple, metal-free and acid / alkali-free pyridine derivative by using economic and convenient D2O at room temperature. The strategy has the characteristics of high efficiency and environmental friendliness, has high chemical and regioselectivity, and can provide a wide range of D compounds, such as pyridine, quinolones, N ligands and biological related compounds.

The invention relates to the technical field of polypeptide biosynthesis, in particular to a method for biosynthesizing acetyl tetrapeptide-5, a composition containing the acetyl tetrapeptide-5 and application of the composition. According to the method, low-cost natural amino acid is used as a substrate, specific aminopeptidase or a mutant thereof is used as a biocatalyst, amino acid ligase and polyphosphatase are combined, and acetyl tetrapeptide-5 can be efficiently synthesized through a one-step enzymatic reaction. Compared with a traditional chemical synthesis method, the method has the advantages of low raw material cost, no use of an organic solvent, mild reaction conditions, high regioselectivity, environmental friendliness, low production cost and the like. The invention also provides a composition containing acetyl tetrapeptide-5 and dipeptide-15, the inhibition effect of the composition on grease secretion is obviously better than that of a single component, and the composition has a synergistic oil control effect under a specific ratio.

The invention relates to the technical field of organic silicon catalysis, and discloses a hydrosilylation reaction catalyst and a preparation method thereof, the catalyst is prepared from a platinum complex catalyst solution, maleic anhydride, triphenyl borate, tetraethoxysilane, propylene carbonate and diethylene glycol dibutyl ether; the preparation method comprises the steps of solvent water removal, electronic relay adduct preassembly, active metal introduction, thermal induction aging and the like. An electron-deficient coordination center is constructed through a step-by-step process, the electron cloud density of the platinum center is reduced by utilizing the Lewis acid characteristic of triphenyl borate, and the solvent cage effect of propylene carbonate is matched, so that the high-temperature tolerance of the catalyst is improved, and the generation of platinum black is effectively inhibited; meanwhile, the solubilizing and bridging effects of diethylene glycol dibutyl ether are utilized, the compatibility problem of a high-polarity component and a non-polar silicone oil matrix is solved, and the obtained catalyst has high activity, high regioselectivity and excellent long-term storage stability.

The invention relates to a synthesis method of a branched chain type allyl alcohol compound, which comprises the following steps: under the protection of nitrogen, taking different substituted terminal alkyne and formalin as raw materials, taking metal cobalt salt and an organic ligand as catalysts, taking Hanus ester as a reducing agent, and carrying out a reaction in the presence of an organic solvent and a photosensitizer to obtain the branched chain type allyl alcohol compound. And carrying out illumination reaction to obtain the branched chain type allyl alcohol compound. According to the method, reaction raw materials and reagents are simple and easy to obtain, conditions are mild and easy to control, atom economy is high, precious metal catalysis is not needed, the substrate application range is wide, regioselectivity is high, and wide application prospects are achieved.

The invention discloses an initiation type molecular layer deposition method and a regioselective deposition regulation and control method. The initiation type molecular layer deposition method comprises the following steps: surface activation: placing a substrate in a reaction cavity, and forming a reaction site on the surface of the substrate by using plasma; a monomer is introduced into the reaction cavity, and the monomer acts on the reaction sites and deposits on the surface of the substrate to form a film layer; wherein the monomers comprise a first type of monomers and a second type of monomers, an active group of the first type of monomers comprises at least one double bond, and the second type of monomers comprise siloxane monomers without vinyl and silazane monomers without vinyl; and repeating the steps of surface activation and deposition in sequence until a film with a target thickness is obtained. According to the initiation type molecular layer deposition method, the film layer is prepared for multiple times, high-precision control over the thickness of the thin film is achieved, and the method is suitable for multiple monomers, simple in process and high in compatibility.

The invention discloses a preparation method of an indole-3-yl alkyl malonate compound and a preparation method of the indole-3-yl alkyl malonate compound. According to the method, reaction raw materials which are economical, cheap and easy to obtain are subjected to a three-component C (sp3)-H / C (sp2)-H functionalization reaction under a mild electrochemical condition, and the indole-3-alkyl malonate compound is obtained through one-step construction. According to the method, a C (sp3)-H / C (sp2)-H functionalization regioselective pathway is adopted, and H2 is a unique theoretical byproduct. Mechanism studies show that the reaction generates alkyl free radicals through C (sp3)-H bond oxidation, the free radicals are added to C = C bonds, and single electron oxidation and C (sp2)-H functionalization cascade reaction are carried out. Compared with an existing method, the preparation method has the outstanding advantages that the raw materials are cheap and easy to obtain, the reaction substrate is wide in application range, the target product yield is high, and the atom economy of the reaction is good.

The invention discloses a method for synthesizing a benzodithiepinone derivative through metal-free catalysis, and belongs to the field of organic synthesis. According to the method, benzo disulfonylphenol ketone and alkyne are taken as raw materials, a dual-catalysis system composed of triethylene diamine and bis (diphenylphosphine) methane is adopted, a heating reaction is performed in a 1, 4-dioxane solvent, and the target seven-membered sulfur heterocycle (benzo [e] [1, 4] dithiepin-5-ketone compound) is obtained through separation and purification. According to the method, the problem of regioselective sulfuration of alkyne is effectively solved through a synergistic catalysis mechanism of organic amine and organic phosphine, and high-precision cyclization reaction of benzobissulfonylphenol ketone and alkyne is realized. The process is mild in reaction condition, free of inert gas protection, simple and convenient to operate and good in functional group tolerance, the atom economy can reach 100%, and an efficient and practical synthesis way is provided for construction of the benzo [e] [1, 4] dithiepin-5-ketone compound with a novel structure.

This invention discloses a ruthenium catalyst supported on a phosphine-containing porous organic polymer and its preparation method. The phosphine-containing porous organic polymer serves as both a support and a solid ligand. The phosphine-containing porous organic polymer ligand is a random copolymer, and its structure can be represented by general formula I. The ruthenium catalyst supported on the phosphine-containing porous organic polymer according to this invention has a large specific surface area and contains a hierarchical porous structure, enabling efficient direct preparation of alcohols from olefins via reductive hydroformylation, and is easily recyclable. It exhibits excellent activity and regioselectivity in the direct preparation of alcohols from olefins via reductive hydroformylation, with an alcohol selectivity of nearly 90% and a high ratio of straight-chain alcohols to branched-chain alcohols.

The invention relates to the technical field of organic synthesis, in particular to a preparation method of a 9-aryl xanthene compound. The preparation method of the 9-aryl xanthene compound comprises the following steps: adding a xanthene compound, an aromatic amine compound and a nitrogen-doped carbon material into an organic solvent, and reacting in an oxygen atmosphere; the 9-aryl xanthene compound is novel in structure and can be applied to the fields of medicines, agricultural chemicals, material science and the like, and the preparation method has the advantages of mild reaction conditions, simplicity and safety in operation, high raw material economy, wide substrate applicability and functional group compatibility, good chemical and regioselectivity and the like; a new way is provided for the construction of a novel xanthene derivative.

The application discloses a kind of using cobalt catalyst by unreported double migration coupling strategy, realizes migration asymmetric nitrogen hetero Nozaki-Hiyama-Kishi (aza-NHK) reaction, and the selective preparation α-chiral (E)-allyl amine starting from simple and easy to obtain ortho halogen phenyl ethylene or corresponding E / Z-alkyl bromide or its mixture belongs to the field of organic chemistry and medicinal chemistry.The application under the action of metal cobalt source, ligand, organic additive, inorganic additive etc., makes cyclic sulfonamide and ortho alkenyl substituted aryl halide or alkenyl halide react in organic solvent, to obtain a series of polysubstituted olefins with excellent regioselectivity, stereoselectivity and good yield, which can be used as active drug molecules and important synthetic intermediates.The application uses cheap transition metal cobalt as catalyst, and uses ortho alkenyl substituted aryl iodine and cyclic sulfonamide as raw material, and the reaction condition is warm, simple operation, and good functional group compatibility.

The application discloses a method for synthesizing nitrogen-containing heteroarene carboxylic acid compounds based on nitrogen-containing heteroarene carbon-hydrogen bond carboxylation reaction and belongs to the technical field of organic synthesis, and specifically comprises the following steps: adding a reaction substrate, an organic catalyst, a base and an additive into a reaction container, then adding a solvent under a CO2 atmosphere, and stirring and reacting at room temperature or under heating in a light irradiation condition; and performing post-treatment on a reaction product, separating and purifying the reaction product, and obtaining nitrogen-containing heteroarene carboxylic acid compounds and derivatives thereof. The scheme has the characteristics of mild reaction condition, wide reaction substrate range, good yield and good regioselectivity, and cheap and easily-obtained raw materials, can efficiently realize nitrogen-containing heteroarene carbon-hydrogen bond carboxylation reaction, synthesize important nitrogen-containing heteroarene carboxylic acid compounds, and has a good application prospect.

The invention belongs to the technical field of biosynthesis, and particularly relates to a method for preparing chiral alcohol through asymmetric reduction of large steric hindrance rigid ketone based on aldehyde ketoreductase and a mutant thereof. Comprising the following steps: adding a recombinant Escherichia coli wet cell for expressing aldehyde ketoreductase, a recombinant Escherichia coli wet cell for expressing formate dehydrogenase, a buffer solution, a substrate, a cosolvent, ammonium formate and coenzyme into a reaction container, reacting at a certain temperature, and after the reaction is completed, extracting, separating and carrying out rotary evaporation to obtain a product alcohol. The biological catalysis method is mild in reaction condition, environmentally friendly and high in regioselectivity and stereoselectivity, chiral resolution and heavy metal residues in products are avoided, and the defects of a chemical method are exactly overcome.

The invention belongs to the technical field of preparation of four-membered ring derivatives, and particularly relates to a four-membered ring derivative and a preparation method thereof. The preparation method of the four-membered ring derivative comprises the following steps: (1) adding two substrates, a photocatalyst and a solvent into a quartz tube, and stirring; (2) putting the quartz tube under ultraviolet light to carry out photocatalytic reaction; and (3) evaporating the reaction liquid to dryness, and separating through column chromatography to obtain the target compound. According to the invention, cis-olefin is used as an initial raw material to carry out cycloaddition reaction, so that the method has high regioselectivity and diastereoselectivity; the homodimerization reaction of olefin is effectively inhibited through reversible cis-trans isomerization reaction, so that the four-membered ring derivative is efficiently obtained. The four-membered ring derivative prepared by the invention plays a basic role in drug design, and provides a solid structural support for medical molecules.

The invention discloses a diketopiperazine heterodimer as well as a biosynthesis method and application thereof, and belongs to the technical field of bioengineering. The biosynthesis method of the diketopiperazine heterodimer comprises the following steps: S1, culturing a recombinant cell containing P450 dimerization enzyme or a mutant thereof, and performing induced expression to obtain a whole-cell culture; and S2, adding a cyclic dipeptide substrate containing tryptophan into the whole-cell culture, carrying out a catalytic reaction, and separating and purifying the obtained product to obtain the diketopiperazine heterodimer. According to the invention, the P450 dimerization enzyme or the mutant thereof is used for catalyzing the biosynthesis of the tryptophan-containing diketopiperazine into the diketopiperazine heterodimer with different regioselectivity / stereoselectivity, the biosynthesis method is green and environment-friendly, the efficiency is high, and the variety of the diketopiperazine heterodimer is greatly expanded.

The invention discloses a non-specific peroxidase HecUPO derived from Hypoxylon sp. (strain EC38), wherein the amino acid sequence of the non-specific peroxidase HecUPO is as shown in SEQ ID NO: 1. The enzyme can efficiently catalyze testosterone to generate 16 alpha-hydroxylation reaction to generate C16 alpha-hydroxytestosterone, the conversion rate reaches 70%, the separation yield reaches 82%, no by-product is generated, and the C16 alpha-hydroxytestosterone has excellent regioselectivity. The invention also discloses a gene for coding the HecUPO, a recombinant plasmid pPICZA-HecUPO containing the gene, a recombinant pichia pastoris engineering bacterium and an application of the recombinant pichia pastoris engineering bacterium in steroid hydroxylation. The non-specific peroxidase HecUPO disclosed by the invention has the advantages of being high in catalytic efficiency, specific in regioselectivity, simple in reaction system, green, environmentally friendly and the like, and a new enzymology resource is provided for fixed-point hydroxylation modification of steroid drugs.

Provided are a polyimide compound including a repeating unit having an aromatic diamine component having a specific structure in which a side-chain benzylic position is regioselectively brominated, a gas separation membrane having a gas separation layer containing the polyimide compound, and a gas separation module and a gas separation apparatus each having the gas separation membrane.

The problem addressed by the present invention is to provide a method for producing an O-substituted serine derivative, which makes it possible to produce an O-substituted serine derivative in fewer steps. The inventors have made a wide and in-depth study on the reductive hydrogenation of cyclic N, O-acetal. As a result, the present inventors have found a method for producing an O-substituted serine derivative in fewer steps, which has excellent regioselectivity and chemical yield while maintaining optical purity.

The invention provides a benzo-silicon hybrid eight-membered ring compound with a stereo axis, which is constructed based on palladium-catalyzed alkyne insertion / C-H activation / ring expansion. According to the method, aryl halide, alkyne and silacyclobutane which are simple and easy to obtain are used as initial raw materials and are stirred to react in an organic solvent at the temperature of 40-120 DEG C under the action of a palladium catalyst, a phosphine ligand and alkali, and the benzo-silicon hybrid eight-membered ring compound can be obtained. The method has the advantages of cheap and easily available raw materials, mild reaction conditions, simple preparation process, good regioselectivity, wide substrate application range, easy amplification and the like.

This invention discloses a migration C(sp²)-H / C(sp³)-H cross-coupling reaction achieved using metal / photoredox catalysis, belonging to the fields of organic chemistry and medicinal chemistry. Under the action of a nickel source, photocatalyst, ligands, base, and additives, this invention enables the reaction of alkanes with ortho-alkenyl-substituted aryl halides or ortho-pyridine-substituted aryl halides in an organic solvent under light irradiation, yielding a series of polysubstituted olefins or polysubstituted aromatic compounds with excellent regioselectivity, stereoselectivity, and good yields, which can serve as active pharmaceutical molecules. This invention uses inexpensive transition metal nickel as a catalyst, readily available alkanes and haloaromatics as raw materials, and features mild and simple conditions, good functional group compatibility, and easy operation.

The present invention belongs to the technical field of organic synthesis, and particularly relates to a method for photocatalytic preparation of N-dimercaptobenzamide and its derivatives. The method comprises the following steps: using a compound of formula 1 as a raw material and a compound of formula 2 as a disulfur source, and carrying out a reaction through a photocatalytic system to prepare a compound of formula 3, wherein R<supgt;1< / supgt> and R<supgt;2< / supgt> are each independently selected from an aryl group, an alkyl group or an electron-withdrawing group. The synthesis method of the present invention has simple operation, does not involve metals, has a wide range of applicable reaction substrates, good regioselectivity, high yield, and can greenly and efficiently synthesize a series of novel N-dimercaptobenzamide derivatives, and has broad application prospects in agrochemicals, drug preparation and fluorescent materials.

The invention relates to a cobalt-based catalyst for hydrogenation of a nitro aromatic compound and a preparation method and application thereof. The cobalt-based catalyst comprises a carrier and an active component loaded on the carrier, the carrier is nitrogen-doped carbon, and the active component is metal cobalt; the cobalt-based catalyst is prepared by taking cobalt nano colloid as a precursor and loading the precursor on the carrier; the cobalt nano colloid is obtained by interaction of cobalt salt and polyvinylpyrrolidone. Compared with the prior art, the cobalt nano colloid obtained through interaction of polyvinylpyrrolidone and metal cobalt is adopted as the precursor, the loading capacity of the metal cobalt is reduced, the dispersity and stability of the active component are improved, and the preparation process is simple and suitable for large-scale production. Under a mild condition, high-activity and regioselective hydro-conversion of the nitro aromatic compound into the aromatic amine is realized.

To provide excellent cellulose esters.SOLUTION: The present application discloses regioselectively substituted cellulose esters, films made from the regioselectively substituted cellulose esters and methods for making the same. The regioselectively substituted cellulose esters are synthesized using trifluoroacetic anhydride and cellulose with various acyl donors or acyl donor precursors.SELECTED DRAWING: None

The invention discloses a synthesis method of 2 '-O-methyladenosine, and belongs to the technical field of nucleoside synthesis and medicinal chemistry. According to the method, xylose which is rich in source is taken as an initial raw material, eight-step reaction including acetalation protection, acetylation, glycosylation, deacetylation, methylation, deacetalation protection, Mitsunobu reaction and secondary deacetylation is performed, reaction conditions of each step are accurately controlled, and finally, a target product is synthesized. The method has the advantages of high methylation reaction regioselectivity, mild reaction conditions, cheap and easily available raw materials and controllable cost, and overcomes the problems of poor methylation reaction regioselectivity, harsh reaction conditions and high cost in the existing synthesis method. The obtained product has important application value in the fields of research and development of antiviral drugs, design of nucleic acid probes and the like.

The present invention provides a method for preparing polysubstituted 1,2,3,4-tetrahydroquinoline, which relates to the technical field of the synthesis of chemical intermediates for medicines and natural compounds. In the present invention, o-N-acylphenyl MBH carbonate and an unsaturated olefin are used as raw materials, and under the action of a Lewis base catalyst, a [4+2] cycloaddition reaction occurs in an organic solvent to generate a polysubstituted 1,2,3,4-tetrahydroquinoline compound. The diastereoselectivity and regioselectivity of the product are high. Without the need for a metal catalyst, the reaction product can be obtained in one step. The reaction conditions are mild, and it only needs to be stirred at room temperature in an organic solvent. The raw materials are easily available, the cost is low, the process is stable and the yield is high. The operation and post-treatment are simple. Moreover, the product can be prepared in gram scale and further derivatized and transformed, providing a reference for drug research and development.