A series of alpha,alpha-disubstituted aziridinemethanols have been designed and synthesized as chiral auxiliaries for the enantioselective reduction of acetophenone. Some of them catalyzed the reduction with excellent ee (up to 97%) under more facile reaction conditions. Furthermore. the results showed that a,a-disubstituted aziridinemethanols with electron-withdrawing groups led to much higher enantioselectivity than those with electron-donating groups, which allowed the rational modification of catalyst structure to achieve optimal enantioselectivity. (C) 2008 Elsevier B.V. All rights reserved.