16results about How to "High ee value" patented technology

The invention belongs to the technical field of biology, and discloses a halohydrin dehalogenase mutant, a coding gene, a recombinant vector, a recombinant strain, an enzyme preparation and application of the halohydrin dehalogenase mutant, the coding gene, the recombinant vector, the recombinant strain and the enzyme preparation in synthesis of chiral (S)-5-phenoxymethyl-2-oxazolidinone compounds. The halohydrin dehalogenase mutant is obtained by performing combined mutation on an enzyme with an amino acid sequence as shown in SEQ ID NO.1 at the 15th site, the 137th site and the 179th site. The mutant can obviously improve the ee value of a chiral (S)-5-phenoxymethyl-2-oxazolidinone compound synthesized by catalyzing phenyl glycidyl ether, the purity of catalytic synthesis and resolution is higher, and industrial production is facilitated.

The invention provides a method for constructing planar chiral [2, 2] paracyclophane by cobalt-catalyzed asymmetric carbon-hydrogen bond activation-kinetic resolution, which comprises the following steps: by using a cobalt catalyst, a chiral ligand and an additive, taking a graphite felt electrode as an anode and taking a platinum sheet electrode as a cathode, carrying out racemization on [2, 2] paracyclophane under the condition of direct-current electrolysis, so as to obtain the planar chiral paracyclophane. The preparation method comprises the following steps: carrying out asymmetric carbon-hydrogen bond dehydrogenation coupling / kinetic resolution on 2, 2] paracyclophane formamide and aryl acid, and after the reaction is finished, carrying out corresponding post-treatment to obtain planar chiral [2, 2] paracyclophane formamide and planar chiral oxopara-[2, 2] paracyclophane; according to the method, electrochemical synthesis of planar chiral oxara-[2, 2] paracyclophane is realized through a method for catalyzing asymmetric carbon-hydrogen bond activation by virtue of a crustal high-yield transition metal, a reaction substrate is wide in universality and excellent in stereoselectivity, and a product and a split and recycled raw material can have an excellent ee value (up to gt; 99% ee) and a splitting factor (up to 1057).

The application relates to a method for asymmetric alkylation reaction of a chain racemic allyl ether, which comprises the following steps: uniformly mixing a chain racemic allyl ether, a Grignard reagent, a phosphoramidite ligand, a catalyst, boron trifluoride ether and a solvent, and carrying out asymmetric allyl alkylation reaction to prepare an asymmetric allyl alkyl compound; the asymmetric allyl alkyl compound has the following structural formula: wherein, R 1 is a primary alkyl or secondary alkyl, R 2 is a primary alkyl, and the asymmetric allyl alkyl compound is a mixture containing Z configuration and E configuration. The application utilizes the chain racemic allyl methyl ether as a substrate to carry out asymmetric allyl alkylation reaction, and constructs a chain olefin with optical activity. The chain racemic allyl methyl ether as a raw material has excellent reaction activity and enantioselectivity, is high in stability, is not prone to deterioration, and is easy to store.

The present invention relates to a ketoreductase mutant and its application. The ketoreductase mutant is obtained by mutation of the amino acid sequence shown in SEQ ID NO: 1, wherein the mutation includes at least one of the following mutation sites: the 113th position is mutated from N to R or K, the 141st position is mutated from S to A, D, E, G or V, the 149th position is mutated from D to A or F, the 152nd position is mutated from W to H, L, M or Y, the 197th position is mutated from A to M or F, and the 207th position is mutated from S to A or T. The ketoreductase mutant can be applied to the green chemical synthesis of chiral alcohol compounds, has high catalytic activity and good stability. Compared with the chemical synthesis method, the reaction catalyzed by the ketoreductase mutant is simple and mild, has high reaction selectivity, low preparation cost, and has good application prospects.

The application discloses a kind of photocontrol chiral ligand based on diarylethene, structural general formula is as shown in following formula:After the photocontrol chiral ligand based on diarylethene synthesized in the application and rhodium catalyst coordination, when catalyzing asymmetric carbon hydrogen amidation at room temperature, higher reaction yield and higher ee value can be obtained by using ligand in open loop state to catalyze, and lower reaction yield and lower ee value can be obtained by using ligand in light stable state to catalyze.The application makes up the deficiency that there is currently lack of photo-thermal bistable photocontrol catalyst in the field of photocontrol asymmetric catalysis, and widens the application of diarylethene in photocontrol asymmetric catalysis.

This invention discloses a nitrile hydrolase mutant, an engineered bacterium, and its application in the synthesis of (R)-3-cyanohexanoic acid. The nitrile hydrolase mutant is obtained by single or multiple mutations at positions 135, 199, and 59 of the amino acid sequence shown in SEQ ID NO.2. This invention utilizes directed evolution technology to enhance the activity and stereoselectivity of the nitrile hydrolase by constructing a nitrile hydrolase mutant. Compared to the parental nitrile hydrolase PgNITmut, the enantiomeric selectivity (E value) of the mutant PgNITmut / F135L for the substrate 3-cyanohexanonilonitrile is increased from 332 to 419; the activity of the mutant PgNITmut / F135L / R199W is increased by 1.36 times, and the E value is increased to 461; the activity of the mutant PgNITmut / F135L / R199W / T59D is increased by 2.05 times, and the E value is increased to 569. The nitrile hydrolase mutant of this invention has high activity and stereoselectivity. It can be used to synthesize the chiral intermediate (R)-3-cyanohexanoic acid of buvasidan by a highly efficient nitrile hydrolase method, which greatly reduces the cost of industrial production and has good application prospects in the industrial production of buvasidan.

This invention discloses a reductase mutant and its application in the preparation of S-Bosein. The reductase mutant differs from the amino acid sequence shown in SEQ ID NO:3 in containing one or more amino acid residues at sites Q95, L96, and G190. The reductase mutant of this invention exhibits high substrate conversion and high ee value of S-Bosein when using β-pyruvate as a substrate, making it suitable for industrial production.

The invention provides a macrocyclic ketone compound and a preparation method thereof, and belongs to the technical field of organic synthesis. (E)-3-methylcyclopentadecanone is subjected to an asymmetric catalytic hydrogenation reaction under the action of a catalyst to obtain a product (-)-(R)-3-methylcyclopentadecanone. The invention prepares an efficient chiral catalyst, which can selectively catalyze the hydrogenation reaction of (E)-3-methylcyclopentadecanone, prepare (-)-(R)-3-methylcyclopentadecanone with high yield and high selectivity, and the reaction conditions are mild and easy to realize industrial application.

The invention relates to a method for preparing (R)-salbutamol. Specifically, L-threonine and a compound 1 are taken as raw materials, a compound 2 is formed under the catalysis of L-threonine transaldolase, the compound 2 is formed into a compound 3 under the catalysis of decarboxylase, on the basis, the compound 3 is taken as a substrate, and the (R)-salbutamol is further synthesized. And the method has the characteristics of low cost of raw materials and auxiliary materials, short process steps, simplicity and convenience in operation, mild reaction conditions and environmental friendliness.

The invention discloses a preparation method and an intermediate of a sulfonamide compound, and belongs to the field of organic synthesis. The method comprises the following specific steps: in the presence of an alkali reagent and a second solvent, reacting a compound shown as a formula II with p-toluene sulfonamide to generate a compound shown as a formula III; the preparation method of the compound as shown in the formula II comprises the following step: in the presence of an acid-binding agent and a first solvent, reacting a compound as shown in the formula I with a sulfonylation reagent to generate the compound as shown in the formula II. Alcohol is adopted as an initial raw material, sulfonylation is performed firstly, and then the alcohol reacts with sulfonamide under the alkaline condition, so that the synthesis steps are effectively shortened, dangerous intermediates are not needed, and the whole production process is safer; and the total yield of the two steps is high. # imgabs0 #

The invention relates to a luminescent liquid crystal raceme, a chiral luminescent molecule and a preparation method thereof. The structural formula of the raceme of the light-emitting liquid crystal is shown as a formula (rac)-IV: # imgabs0 #, wherein R1 and R2 are independently selected from substituted or non-substituted alkyl. The luminescent liquid crystal raceme with the structural formula shown as the formula (rac)-IV has the nematic phase liquid crystal property at the room temperature. A small amount of single chiral isomer is added into a raceme of the luminescent liquid crystal with the nematic liquid crystal property at the room temperature, and the ee value of the raceme is slightly increased, so that the chiral luminescent liquid crystal with the chiral nematic liquid crystal property at the room temperature can be obtained. The use amount of the single chiral isomer is greatly reduced, so that the cost of forming the chiral liquid crystal is greatly reduced. The blue fluorescence emitted by the chiral light-emitting liquid crystal and the red fluorescence emitted by the doping system provided by the invention are circularly polarized light, and the circularly polarized light-emitting asymmetric factor of the doped red light can be up to 0.13.

The invention belongs to the technical field of chemical synthesis, and relates to a method for synthesizing a chiral alpha-non-natural aromatic amino acid derivative under visible light driving. The preparation method comprises the following steps: carrying out in-situ matching on a compound 1 and a ligand under the action of a catalyst, and then continuously carrying out photocatalytic coupling reaction on the compound 1 and a compound 2 under the action of an additive to obtain a compound 3, namely the chiral alpha-non-natural aromatic amino acid derivative. Rich types of natural carboxylic acids exist in the nature, redox active ester derived from aromatic acetic acid is adopted as an aryl donor, a guarantee is provided for structural diversity synthesis of chiral alpha-non-natural aromatic amino acid, a non-natural amino acid compound library can be enriched to a great extent, and assistance is provided for development of polypeptide innovative drugs.

The invention provides a method for synthesizing a rusotinib intermediate through asymmetric hydrogenation, which comprises the following specific steps: complexing a metal precursor and a ligand in a second solvent in an inert atmosphere to generate a catalyst; in a hydrogen atmosphere, in a first solvent, a compound shown as a formula (I) reacts under the catalysis of a catalyst to prepare a compound shown as a formula (II). The rusotinib is prepared through efficient asymmetric catalysis of an Rh reagent, the conversion rate reaches 99%, the ee value reaches 99% or above, the usage amount of the catalyst is small, the TON of the catalyst is high, high regioselectivity and high enantioselectivity are achieved, and reference is provided for industrialization of rusotinib bulk drugs. # imgabs0 #

The invention discloses a method for preparing a cyclic chiral nitrile compound and its application in preparing ramelteon, and the preparation steps are as follows: first, a chiral rhodium catalyst is prepared using a rhodium metal precursor and a chiral diphosphine ligand as raw materials; then, a chiral rhodium catalyst is used to catalyze an α, β-unsaturated nitrile outside the ring for asymmetric hydrogenation reaction, and a cyclic chiral nitrile compound is successfully prepared. Compared with the existing method for synthesizing cyclic chiral nitrile compounds, the method of the present invention is simple and practical to operate, has high atom economy, high catalytic efficiency, high yield and high ee value. The present invention also provides a reduction acylation reaction of 2-(1,2,6,7-tetrahydro-8H-indeno[5,4-b]furan-8-yl)acetonitrile with propionic anhydride and sodium borohydride under nickel catalysis, and ramelteon is successfully prepared. The method has the characteristics of simple operation and higher yield, which provides a more efficient, convenient and safe method for the synthesis of ramelteon.

The invention relates to a ligand, a catalyst, chiral alcohol and a synthesis method thereof, and belongs to the technical field of chemical synthesis. The ligand is shown as the result of the ligand A. The catalyst is formed by complexing the ligand A and a transition metal precursor. The catalyst is used for preparing chiral alcohol. The chiral alcohol prepared by catalysis of the catalyst has the advantages of high product yield, high ee value, low cost and the like. # imgabs0 #

The invention provides a BODIPYs compound with axial chirality or boron chirality and a preparation method and application thereof, the BODIPYs compound with the boron chirality has a structure as shown in a formula I or a formula II, and the BODIPYs compound with the axial chirality has a structure as shown in a formula III. The BODIPYs compound with axial chirality or boron chirality is constructed through diazo naphthoquinone or diazo indole and the achiral BODIPYs compound, raw materials are easy to obtain, operation is easy, the BODIPYs compound is suitable for large-scale production, the reaction rate is high, the catalytic efficiency is high, reaction conditions are mild, safety and high efficiency are achieved, and the ee value of the obtained chiral product is high.