Asymmetric conjugate addition of thiols to (E)-3-crotonoyloxazolidin-2-one by iron or cobalt/pybox catalyst

The enantioselective conjugate addition of thiols to (E)-3-crotonoyloxazolidin-2-one was effectively catalyzed by the Fe(BF4)(2)center dot 6H(2)O/(S,S)-ip-pybox catalyst. and the addition product was obtained with up to a 95% ee. Furthermore, the CO(ClO4)(2)center dot 6H(2)O/(S,S)-ip-pybox catalyst also catalyzed the same reaction with a high enantioselectivity. (c) 2008 Elsevier Ltd. All rights reserved.