Enantiodivergent deprotonation/acylation of α-amino nitriles

Abstract

Back to 'base'ics: The title reaction of enantioenriched α-ureidonitriles was found to proceed in a highly enantiodivergent manner despite the intermediacy of stereolabile α-nitrile metallocarbanions. Enantiodivergence is dependent upon the base used. For the less basic hexamethyldisilazides (HMDS), deprotonation in which a metal (M) cation is precomplexed with an electrophile is proposed. LDA=lithium diisopropylamide.

Keywords: asymmetric synthesis; carbanions; cyanides; lithium; metalation.