| abstract |
A one step catalytic asymmetric process for the synthesis of an optically active compound of formula la or lb wherein R is selected from C1-7 alkyl, C1-7 haloalkyl, C1-7 alkoxy, C1-7 haloalkoxy, halogen and hydroxy; R3 is H or C1-4 alkyl; R4 is selected from H, C1-7 alkyl, C1-7 haloalkyl, C1-7 alkoxy, COOH, CO-C1-7 alkoxy and an optionally substituted aryl or heterocycle; AR represents C1-7 alkyl, optionally substituted aryl, an optionally substituted heterocycle or AR and R4 may be bridged together forming part of a ring system; X is O or S; m is a number between 0-4; comprising the step of reacting a compound of the formula 2 with a compound of formula 3 in the presence of a catalytic amount of a chiral nitrogen containing organic compound. |