Kinetics resolution method

A chemical synthesis and catalyst technology, applied in organic chemistry methods, chemical instruments and methods, organic chemistry, etc., can solve the problems of high cost, low efficiency, reduced product yield, chiral purity and chemical purity, etc., to reduce consumption , the effect of cost reduction
CN1649861AInactive Publication Date: 2005-08-03SHASUN PHARMA SOLUTIONS LTD
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
SHASUN PHARMA SOLUTIONS LTD
Publication Date
2005-08-03
Estimated Expiration
Not applicable · inactive patent

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Abstract

A method for stereoselective chemical synthesis, includes the steps of: (A) reacting a nucleophile and a chiral or prochiral cyclic substrate, said substrate comprising a carbocycle or a heterocycle having a reactive center susceptiable to nucleophilic attack by the nucleophile, in the presence of a chiral non-racemic catalyst to produce a product mixture comprising a stereoisometrically enriched product wherein the product mixture further comprises a catalyst residue, at least a portion of the catalyst residue is in a first oxidation state, and the catalyst residue in the first oxidation state is active in catalyzing degradation of the stereoisomerically enriched product, and (B) chemically or electrochemically changing the oxidation state of the catalyst residue form the first oxidation state to a second oxidation state, wherein catalyst residue in the second oxidation state is less active in catalyzing degradation of the stereoisomerically enriched product than is catalyst residue in the first oxidation state. The method reduces erosion of the chiral purify of the stereoisomerically enriched product and reduces the chemical transformation to side products of the stereoisomerically enriched product and co-product(s).
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Description

field of invention

[0001] The present invention relates to stereoselective chemical synthesis methods, more particularly, the present invention relates to stereoselective chemical synthesis methods by kinetic resolution of racemic terminal epoxides. Background of the invention

[0002] Kinetic resolution of racemic terminal epoxides, more specifically hydrolytic kinetic resolution ("HKR"), is an efficient and practical industrial method for obtaining enantiomerically enriched epoxides and 1,2-diol. The HKR method is catalyzed by cobalt(III) complexes of chiral salen ligands, which can be prepared from the corresponding Co(II) complexes or from salen ligands and Co(II) salts under air or oxygen Direct reaction preparations, see, for example, U.S. Patent 6,262,278B1 "STEREOSELECTIVE RING OPENING REACTIONS" issued July 17, 2001 to Eric N. Jacobsen et al. and Ready, J.M., Jacobsen, E.N., "Highly Active Oligomeric (salen) CoCatalysts for Asymmetric Epoxide Ring Opening Reaction...

Claims

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