76results about How to "High enantiomeric excess" patented technology

The invention relates to a method for preparing a sulphoxide compound of formula (I) either as a single enantiomer or in an enantiomerically enriched form, comprising the steps of:a) contacting a pro-chiral sulphide of formula (II) with a metal chiral complex, a base and an oxidizing agent in an organic solvent; and optionallyb) isolating the obtained sulphoxide of formula (I).wherein n, Y, R1, R1a, R2 and R2a are as defined in claim 1.

The present invention relates to a method for the deracemisation or chiral inversion of chiral amines by enzymatic treatment. The method employs a stereoselective enzymatic conversion and either a non-selective or partially selective chemical or enzymatic conversion, simultaneously or sequentially. The invention also provides a method for selecting a suitable enzyme, particularly a suitable amine oxidase, and for the generation of novel enzymes suitable for use in the deracemisation method.

A method for efficiently producing L-2-amino-4-(hydroxymethylphosphinyl)-butanoic acid, useful as a herbicide, by a catalytic asymmetric synthesis reaction with a high asymmetric yield. The method includes a step in which a compound represented by the below formula (1) and a benzylamine are reacted in the presence of dehydrating agent, then the resulting mass is reacted with hydrogen cyanide in the presence of an asymmetric catalyst, followed by acid hydrolysis, further followed by elimination of a protective group. [chemical formula 1] (1) (where, R1 represents a C1-4 alkyl group).

Disclosed is a method for efficiently and highly selectively producing L-2-amino-4-(hydroxymethylphosphinyl)-butanoic acid, which is useful as a herbicide, through a catalytic asymmetric synthesis reaction. Specifically disclosed is a method for producing L-2-amino-4-(hydroxymethylphosphinyl)-butanoic acid which is characterized in that a dehydroamino acid is subjected to an asymmetric hydrogenation by using a rhodium catalyst represented by the formula (2) below and having an optically active cyclic phosphine ligand, and then the resulting product is subjected to hydrolysis:[Rh(R4)(L)]X  (2)[where R4 represents 1,5-cyclooctadien or norbornadien; L represents a substance represented by the following formula (6):(wherein R5 and R8 respectively represent a C1-4 alkyl group; R6 and R7 respectively represent hydrogen atom or hydroxyl group; and Y represents a group selected from groups represented by the following formula (7):(where Me represents methyl group)).].

The invention discloses engineering bacteria for expressing L-lactate dehydrogenase subjected to orthogenetic evolution, which is engineering escherichia coli capable of heterologously expressing NAD (Nicotinamide Adenine Dinucleotide) independent L-lactate dehydrogenase subjected to orthogenetic evolution. The engineering bacteria can highly express corresponding mutant protein on the basis of commercial escherichia coli C43 (DE3) and through transporting an expression vector pETDuet-1-mlldD containing the mutant NAD independent L-lactate dehydrogenase, and has the S-mandelic acid degrading activity. The invention also discloses an application of the engineering bacteria in the resolution of racemic mandelic acid. The racemic mandelic acid is conducted through taking intact cells of the constructed engineering bacteria as a catalyst, and meanwhile, homochiral R-mandelic acid and benzoyl formic acid are produced. The engineering bacteria has the advantages of high substrate utilization rate, high product concentration, high optical purity, simplicity and convenience in future extraction, and the like.

The invention discloses a method for splitting (±)-methyl mandelate by esterase. It hydrolyzes (±)-methyl mandelate in the presence of esterase EST04211, and esterase EST04211 catalyzes S-methyl mandelate to generate S-mandelic acid, and then reacts R-methyl mandelate and S ‑Mandelic acid is separated, and the amino acid sequence of the esterase EST04211 is shown in SEQ ID NO.2. Compared with the traditional chemical resolution, the present invention has the advantages of mild reaction conditions, no pollution, and high enantiomeric excess value; compared with the currently reported enzymatic catalytic resolution, the esterase EST04211 used preferentially hydrolyzes the S-configuration Methyl mandelate yields optically pure R-mandelic acid methyl ester and S-mandelic acid with strong stereoselectivity. The obtained product can be used for the synthesis of corresponding drugs after simple purification.

The invention provides a method for preparing (S)-1-(3,5-bis (trifluoromethyl)) phenylethanol by microbial transformation. The (S)-1-(3,5-bis (trifluoromethyl)) phenylethanol is prepared according to The invention provides a method for preparing (S)-1-(3,5-bis (trifluoromethyl)) phenylethanol by microbial transformation. The (S)-1-(3,5-bis (trifluoromethyl)) phenylethanol is prepared according tothe following steps: 1-(3,5-bis (trifluoromethyl)) phenylethanol functioning as substrate is catalyzed by fermentation products of Candida tropicalis 104 functioning as enzyme source so as to be reducthe following steps: 1-(3,5-bis (trifluoromethyl)) phenylethanol functioning as substrate is catalyzed by fermentation products of Candida tropicalis 104 functioning as enzyme source so as to be reduced asymmetrically at 28-34 DEG C, and transformation solution is separated and purified after the asymmetric reduction reaction. The Candida tropicalis 104 is chosen to be used as enzyme-producing stred asymmetrically at 28-34 DEG C, and transformation solution is separated and purified after the asymmetric reduction reaction. The Candida tropicalis 104 is chosen to be used as enzyme-producing strain after optimum strain seeking, and 1-(3,5-bis (trifluoromethyl)) phenylethanol is catalyzed to be reduced asymmetrically in a single-phase aqueous system so as to generate (S)-1-(3,5-bis (trifluoroain after optimum strain seeking, and 1-(3,5-bis (trifluoromethyl)) phenylethanol is catalyzed to be reduced asymmetrically in a single-phase aqueous system so as to generate (S)-1-(3,5-bis (trifluoromethyl)) phenylethanol which has an enantiomeric excess value of over 99 percent and can be well applied.methyl)) phenylethanol which has an enantiomeric excess value of over 99 percent and can be well applied.

A process for producing an optically active amine compound, characterized by asymmetrically hydrogenating a prochiral carbon-nitrogen double bond in the presence of a ruthenium complex represented by general formula (1) or (2) (wherein P represents an optically active diphosphine, X represents an anionic group, and Ar represents an optionally substituted arylene group).

Provided is a process for the preparing 1-phenyl-3-dimethylaminopropane derivatives of formula I, (The formula should be inserted here) and its pharmaceutically acceptable salts thereof via novel intermediates.