230 results about "Kinetic resolution" patented technology

The invention discloses a method for catalyzing dynamic kinetic resolution of arylamine via a racemization catalyst, comprising the following steps of: 1) adding p-chlorophenol, n-pentanoic acid, dicyclohexylcarbodiimide and 4-dimethylamino-pyridine, and carrying out mixing, filtration, drying, concentration and column chromatography to obtain a pentanoic acid p-chlorophenyl ester acyl donor; 2) carrying out coprecipitation on magnesium chloride solution and aluminum chloride solution and carrying out water-heat treatment to obtain chloridion intercalated hydrotalcite, adding the chloridion intercalated hydrotalcite in lauryl sodium sulfate aqueous solution, and carrying out backflow, cooling, centrifugation, water washing, acetone washing and drying to obtain a carrier; 3) adding palladium salt and the carrier, and carrying out heating, ascorbic acid addition, centrifugation, water washing, acetone washing and freeze-drying to obtain the racemization catalyst; and 4) adding arylamine, the acyl donor, lipase and the racemization catalyst in toluene and placing in a stainless steel reactor to add hydrogen so as to obtain amide. The method provided by the invention is used for catalyzing the dynamic kinetic resolution of arylamine, has rapid reaction rate, low temperature, high conversion rate and high product optical purity, and has great application value.

The invention provides a preparation method of trans-(1R, 2S)-2-(3, 4-difluoro phenyl) cyclopropylamine. The preparation method comprises the following steps: enabling racemic chloro phenethyl alcohol (I) and N-protection proline to undergo a reaction under the effects of a condensing agent A1 and a catalyst C1, and obtaining chiral chlorohydrin (II); enabling the chiral chlorohydrin (II) to generate an epoxy compound (III) under the conditions of alkalinity; enabling the epoxy compound (III) and TEPA to react and generate cyclopropyl ethyl formate (IV) under the conditions of alkalinity; removing ester from cyclopropyl ethyl formate (IV) under the conditions of alkalinity, and generating cyclopropanecarboxylic acid (V); and enabling cyclopropanecarboxylic acid (V) and azide to generate a target compound (3) by Curtius rearrangement. The preparation method has the advantages that the steps of a used synthetic process route are few, the operation is simple, and industrial production is achieved easily; a kinetic resolution method is utilized to synthesize chiral chlorohydrin (II) and is simple in reaction conditions and easy to operate; and a TEPA method is utilized synthesize the cyclopropyl ethyl formate, the product yield is high, cis-trans selectivity is good, and the purity is over 99%.

The invention discloses a preparation method of R-3, 5-bis (trifluoromethyl) phenyl ethanol. According to the preparation method disclosed by the invention, 3, 5-bis (trifluoromethyl) phenyl ethanol is taken as a raw material, chlorophenol acetate is taken as an acyl donor, Novozym435 is taken as a resolution catalyst, acidic resin is taken as a racemic catalyst, and then dynamic kinetic resolution is performed to obtain R-3, 5-bis (trifluoromethyl) phenyl ethanol acetate. Then, ester is hydrolyzed to obtain R-3, 5-bis (trifluoromethyl) phenyl ethanol, the final product yield can be more than 90%, and the ee value of the product is more than 99%. The method is simple to operate, the used racemic catalyst has the characteristics of low price, easiness in obtainment, reusability, high product yield, good optical purity and the like, and the method further has great guide and application values in production and preparation processes of R-3, 5-bis (trifluoromethyl) phenyl ethanol.

Chiral ligands and metal complexes based on such chiral ligands useful in asymmetric catalysis are disclosed. The metal complexes according to the present invention are useful as catalysts in asymmetric reactions, such as, hydrogenation, hydride transfer, allylic alkylation, hydrosilylation, hydroboration, hydrovinylation, hydroformylation, olefin metathesis, hydrocarboxylation, isomerization, cyclopropanation, Diels-Alder reaction, Heck reaction, isomerization, Aldol reaction, Michael addition; epoxidation, kinetic resolution and [m+n] cycloaddition. Processes for the preparation of the ligands are also described.

Materials and methods for preparing (S)-(+)-3-aminomethyl-5-methyl-hexanoic acid and structurally related compounds via enzymatic kinetic resolution are disclosed.

The present invention describes a method for lipase kinetic resolution of 2-(3-chlorophenyl)propionic acid enantiomers. By use of efficient selective lipase, racemic 2-(3-chlorophenyl)propionate is catalytically hydrolyzed in an aqueous medium to resolve 2-(3-chlorophenyl)propionic acid. Through addition of surfactant PEG400 to the reaction system, the substrate conversion rate is greatly increased. The optical purity of the product is >=97%, and the conversion rate is >=40%. Compared with other resolution technologies, the method has mild reaction conditions, simple operation and low environmental pollution, and provides a feasible method for the production of (S)-Pirprofen in the pharmaceutical industry.

The present invention relates to a process for stereoselective or regioselective chemical synthesis which generally comprises reacting a nucleophile and a chiral or prochiral cyclic substrate in the presence of a non-racemic, chiral catalyst to produce a stereoisomerically- and / or regioisomerically-enriched product. The present invention also relates to hydrolytic kinetic resolutions of racemic and diastereomeric mixtures of epoxides.

The invention relates to a 4-(N,N-dimethyl) aminopyridine derivate and a synthesis method thereof. The derivate has a structural formula shown in the specification of the invention, wherein R is -PH and -CN. Under the more common condition or microwave condition, the invention synthesizes 11 4-(N,N-dimethyl) aminopyridine derivates with higher yields. A chiral N,N dimethyl aminopyridine analogue is applied to asymmetric kinetic resolution of secondary alcohol 1-phenylethanol to obtain a medium value of ee percent.

One aspect of the present invention relates to quinine-based and quinidine-based catalysts. In certain embodiments, the quinine-based and quinidine-based catalysts contain a hydroxy group at the 6′ position. In certain embodiments, the quinine-based and quinidine-based catalysts contain an O-aryl group or an O-aroyl group at the C9 position. In certain embodiments, the quinine-based and quinidine-based catalysts contain an optionally substituted O-diazene group or an optionally substituted O-benzoyl group at the C9 position. In certain embodiments, the quinine-based and quinidine-based catalysts contain a thiourea at the C9 position. In certain embodiments, the quinine-based and quinidine-based catalysts contain an NH(═S)NH-aryl group at the C9 position. Another aspect of the present invention relates to a method of preparing a chiral, non-racemic compound from a prochiral electron-deficient alkene or prochiral imine, comprising the step of: reacting a prochiral alkene or imine with a nucleophile in the presence of a catalyst; thereby producing a chiral, non-racemic compound; wherein said catalyst is a derivatized quinine or quinidine. In certain embodiments, the nucleophile is a malonate or β-ketoester. In certain embodiments the nucleophile is an alkyl or aryl or aralkyl 2-cyano-2-alkylacetate. In certain embodiments the nucleophile is an alkyl or aryl or aralkyl 2-cyano-2-alkylacetate.Another aspect of the present invention relates to a method of kinetic resolution, comprising the step of: reacting a racemic aldehyde or racemic ketone with a nucleophile in the presence of a derivatized quinine or quinidine, thereby producing a non-racemic, chiral compound. In certain embodiments, the kinetic resolution is dynamic.