Abstract: A process for producing enantiomerically enriched (S)-?-(2-chlorophenyl)-6,7-dihydrothieno[3,2-c]pyridine-5 (4H)-acetic acid hydrocarbyl ester, represented by the formula: Is provided, wherein R1 and R2 are hydrogens and R3 is methyl (i.e., (S)-Clopidogrel).

Abstract: A process for producing enantiomerically enriched (S)-?-(2-chlorophenyl)-6,7-dihydrothieno[3,2-c]pyridine-5 (4H)-acetic acid hydrocarbyl ester, represented by the formula: Is provided, wherein R1 and R2 are hydrogens and R3 is methyl (i.e., (S)-Clopidogrel).

Abstract: A method for making a chiral transition metal-ligand catalyst complex that is active in catalyzing stereoselective ring opening reactions includes contacting an asymmetric tetradentate ligand, in an excess of a Brønsted acid, with a salt of a first row transition metal, wherein the acidity of the conjugate acid of the salt is the same as or less than the acidity of the Brønsted acid, under conditions effective to allow formation of the active chiral transition metal-ligand catalyst complex, and forming a solution of the complex in a water-miscible, protic solvent from which the active complex can be precipitated by the addition of water and adding water to the solution to precipitate at least a portion of the complex.

Abstract: A method for stereoselective chemical synthesis, includes the steps of: (A) reacting a nucleophile and chiral or prochiral cyclic subtrate, said substrate comprising a carbocycle or a heterocycle having a reactive center susceptible to nucleophilic attack by the nucleophile, in the presence of a chiral non-racemic catalyst to produce a product mixture comprising a stereomerically 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 electochemically changing the oxidation state of the catalyst residue from 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.