Patent ID: 7368591

Claim:
A method for preparing a sulphoxide compound of formula (I) either as a single enantiomer or in an enantiomerically enriched form: wherein: Y is —C(═O)X wherein X is —OR 5 ; R1, R1 a , R2 and R2 a are each independently H, halo, (C1-C8)alkyl, (C2-C8)alkenyl, (C2-C8)alkynyl, (C 6 -C 10 )aryl, —CN, —CF 3 , —NO 2 , —OH, (C1-C8)alkoxy, —O(CH 2 ) m NR 6 R 7 , —OC(═O)R 8 , —C(═O)OR 8 , —C(═O)R 8 , —OC(═O)NR 6 R 7 , —O(CH 2 ) m OR 8 , —(CH 2 ) m OR 8 , —NR 6 R 7 , or —C(═O)NR 6 R 7 ; R5 is alkyl, cycloalkyl, aralkyl, alkaryl, or aryl; R6 and R7 are each independently H, (C1-C6) alkyl, or hydroxy(C1-C6)alkyl; R8 is H, alkyl, cycloalkyl, aralkyl, alkaryl, or aryl; n is 1, 2 or 3; and m is 1, 2, 3, or 4; comprising the steps of: a) contacting a pro-chiral sulphide of formula (II): wherein R1, R2, R1 a , R2 a , Y, and n are as defined above, with a metal chiral ligand complex, a base, and an oxidizing agent in an organic solvent, for a time and under conditions effective to produce the sulphoxide of formula I; and optionally b) isolating the sulphoxide of formula (I); wherein said metal chiral ligand complex is selected from the group consisting of C 2 -symmetric diol titanium (IV) complexes, C 3 -symmetric trialkanolamine titanium (IV) complexes, C 3 -symmetric trialkanolamine zirconium (IV) complexes, chiral (salen) manganese (III) complexes, and chiral (salen) vanadium (IV) complexes.