Pure Appl. Chem., 2006, Vol. 78, No. 2, pp. 409-414
http://dx.doi.org/10.1351/pac200678020409
Dual Lewis acid - Lewis base activation in enantioselective additions to aldehydes
Abstract:
Reaction of benzaldehyde with ethyl cyanoformate in the presence of Lewis acidic Ti(IV) complexes of bispyridylamide or salen ligands and Lewis basic amines affords the O-alkoxycarbonylated cyanohydrin. In the presence of the salen-based catalytic system, acetyl cyanide can also be added to benzaldehyde, providing a highly enantioselective direct route to the O-acetylated cyanohydrin.