Expanding the Synthetic Potential of Asymmetric Deprotonation:Arylation of Carbanions

摘要

For over 15 years,synthetic organic chemists have had access to enantioenriched carbanions derived from N-Boc pyrrolidine 1 (Boc = tert-butoxycarbonyl) and O-alkyl carbamates 2 upon treatment with a chiral base comprising sBuLi and (-)-sparteine (Scheme 1).This asymmetric deprotonation methodology was pioneered by the groups of Hoppe and Beak,and has been supplemented by work in which a readily accessible (+)-sparteine surrogate (Scheme 1) was developed.