75results about How to "High enantiomeric excess" patented technology

The invention relates to a bimetallic catalyst for synthetizing vertical structure regular makrolon through catalyzing and activating carbon dioxide to be copolymerized with internal compensation alkyleneoxide. The catalyst is a dual four-tooth or dual three-tooth Schiff alkali complex, of which two metal centers are connected through a biphenyl skeleton. Under the action of single or nucleophilicity co-catalyst, the catalyst can be used for catalyzing the carbon dioxide efficiently to be copolymerized with the internal compensation alkyleneoxide under mild condition and lower concentration of the catalyst to prepare the makrolon, the makrolon can be regulated when the catalyst efficiency is 104-106g polymer/mole catalyst and the polymer molecular weight is between 103 and 105, the makrolon can be regulated when the molecular weight distribution is less than 2 and the vertical structure regularity is between 60-100%, an alternate structure exceeds 98% and the makrolon can be degraded into a small molecular compound. The product selectivity and structure selectivity of the polymer compounds of the catalyst system using a chiral ligand are all above 98%, the enantiomer excess value of the mellow obtained by degradation reaches as high as 99%, so that the bimetallic catalyst provides a broad prospect for industrial application.

The invention discloses a synthesis process of chiral pyrrolidine and intermediates. The synthesis process adopts 2, 5-difluorohalobenze or 5-fluoro-3 halogenated pyridine as the raw material substrate, and employs a chiral catalyst to induce chiral reaction so as to reduce a ketone compound into a corresponding chiral alcohol compound, and then carries out substitution reaction to introduce an easily leavable group to an alcoholic hydroxyl group so as to facilitate ring formation reaction (or carry out ring formation reaction directly). The process provided by the invention has the advantagesof significant increase of product yield and reduction of cost, also the reaction temperature is mild, and the process is easy to control and industrialize.

The iridium catalyzed enantiotropic hydrosubstituting process of aromatic pyridine ring and pyrazine ring uses catalyst system comprising chiral coordination compound of iridium and additive compound. The reaction conditions includes temperature of 0-80 deg.c; solvent of dichloromethane, toluene, tetrahydrofuaran, 1, 2-dichloro ethane, isopropanol, etc.; additive compound of tetrabutyl ammonium iodide, iodine, amine, etc.; pressure of 1-100 atm; substrate/catalyst ratio up to 5000; and chiral coordination compound of diphosphine, N-P compound, S-P compound, etc. The catalyst system is prepared through reaction of iridium precursor and chiral compound in the said solvent and the addition of the additive compound while stirring; and can produce asymmetrical induction up to 96 %. The process of the present invention is environment friendly.

The invention relates to a synthesis method for stereoregularity polyester and a bi-metallic catalyst. The catalyst is a bi-nuclear metal complex formed by connecting two metal centers through a biphenyl or dinaphthalene framework. The catalyst can efficiently catalyze a cyclic anhydride and internal compensation epoxyalkane polymerization reaction under the mild condition and low catalyst concentration to prepare polyester under the effect of a nucleophilic co-catalyst, the catalysis efficiency is 103-106 g of a polymer per mole of the catalyst, the molecular weight of the polymer can be adjusted within the range of 103-105, the molecular weight distribution is smaller than 2, stereoregularity can be adjusted within the range of 60-100%, the alternative structure exceeds 98%, and polyester can be degraded into a small molecular compound under a certain condition. A chiral ligand catalytic system is used, the product selectivity and alternative structure selectivity of the polymer are both higher than 98%, the excess value of enantiomer of diol obtained after degradation is higher than 70%, and wide prospects are provided for industrial application.

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 optionally

b) isolating the obtained sulphoxide of formula (I).

• • wherein n, Y, R₁, R_1a, R₂ and R_2a are as defined in claim 1.

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 C_1-4 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)).].

A process for preparing an optically active cyclic sulfoxide, by reacting a cyclic thioether with cumene hydroperoxide or isopropylcumyl hydroperoxide in the presence of alcohol, water or a mixture of water and alcohol and in the presence of a complex of an optically active tartaric acid diester and a titanium (IV) alkoxide in an inert solvent.

To provide a producing method of an optically active β-amino acid useful as intermediate for the production of medicines, agricultural chemicals and physiologically active substances, by means of a catalytic and asymmetric synthesis method of high performance and a high enantiomeric excess, without requiring additional procedures such as introduction and removal of protecting group and so on.

A producing method of an optically active β-amino acids which comprises subjecting an enamine to an asymmetric hydrogenation.

The invention provides compositions comprising an alkene epoxidase and a selective epoxide hydrolase, such as a recombinant microorganism comprising a first heterologous nucleic acid encoding an alkene epoxidase and a second heterologous nucleic acid encoding a selective epoxide hydrolase. Exemplary alkene epoxidases include StyAB, while exemplary selective epoxide hydrolases include epoxide hydrolases from Sphingomonas, Solanum tuberosum, or Aspergillus. The invention also provides non-toxic methods of making enantiomerically pure vicinal diols or enantiomerically pure alpha-hydroxy carboxylic acids using these compositions and microorganisms.

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 C_1-4 alkyl group.)

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.

The invention relates to a synthetic method of optical activity 2, 3-allenes disubstituted carbinol with high enantiomeric excess; optical activity propiolic alcohol reacts with n-butyllithium and chloromethyl ether to generate optical activity 4- hydroxyl-4- aryl-2- butynyl methyl ether which then reacts with grignard reagent (ethyl ether solution) under the catalysis of cuprous bromide, so that the optical activity 2, 3-allenes disubstituted carbinol with high enantiomeric excess can be synthesized. The operation of the method is simple, the raw materials and the reagents are easy to obtain, and the product has high enantioselectivity. The method can simultaneously introduce multiple substitutional groups which are easy to separate and purify, so as to be applicable to synthesizing various substitutional optical activity 2, 3-allenes disubstituted carbinols.

The present invention relates to a process for the asymmetric hydrogenation of imines with hydrogen under elevated pressure in the presence of a catalyst system. In particular the present invention relates to the use of the said catalytic system for the enantioselective hydrogenation of prochiral ketimines to asymmetric amines leading to the formation of herbicides.

The invention provides a method for preparing S-(+)-3-methyl hydroxybutyrate through microbial transformation, which comprises the following steps that: in phosphate buffer solution with the pH value being 5.0 to 8.0, methyl acetoacetate is used as substrates, enzyme-containing strains obtained through fermenting saccharomyces cerevisiae CGMCC No. 2266 are used as microbial catalysts, conversion region is carried out for 8 to 40h at 25 to 45 DEG C, after the reaction is completed, and conversion liquid is prepared into the S-(+)-3-methyl hydroxybutyrate through separation and purification. The method provided by the invention has the main beneficial effects that 1. produced strains are safe and innoxious and are easy to be cultured in a large scale; 2. a large number of biological catalysts can be obtained, and the cost is low; 3. the reaction conditions are mild, and the environmental-friendly effect is realized; 4. the operation is simple and convenient, and the addition of coenzymes with a high price is not needed in the reaction process; and 5. the large-scale industrialized production is easy to realize, and the mol conversion rate is high.

The present disclosure provides methods of preparing a compound of Formula (1): wherein R¹, R², and R³ are as defined as set forth in the application. In one embodiment, a compound of Formula (1) is prepared in >95% chemical purity and >95% enantiomeric excess.

The invention discloses a method for preparing R-mandelic acid by the aid of two-step microbial transformation processes. The method includes carrying out transformation reaction on ethyl benzoylformate, first thalli and buffer solution with a pH (potential of hydrogen) value of 6-8 under conditions of the temperature of 20-45 DEG C and the speed of 100-200 rpm to obtain R-ethyl mandelate; carrying out reaction on the R-ethyl mandelate, second thalli, organic solvents and buffer solution with a pH value of 7-9 under conditions of the temperature of 20-40 DEG C and the speed of 100-200 rpm to obtain the R-mandelic acid. The ethyl benzoylformate is used as a substrate during the transformation reaction, the first thalli are obtained by means of fermentation cultivation by the aid of saccharomyces cerevisiae and are used as catalysts during the transformation reaction, and the buffer solution with the pH value of 6-8 is used as a reaction medium during the transformation reaction. The R-ethyl mandelate is used as a substrate during the reaction, the second thalli are obtained by means of fermentation cultivation by the aid of bacillus cereus and are used as catalysts during the reaction, the organic solvents are used as complex solubilizers during the reaction, and the buffer solution with the pH value of 7-9 is used as a reaction medium during the reaction. The method has the advantages that the method is low in cost and is environmentally friendly, and the reaction conditions are mild; the R-mandelic acid is easy to industrially produce on a large scale; the method is easy and convenient to implement and high in molar transformation rate; the yield can be increased and can reach 99.8%, and the ee value can be increased and can reach 100%.