Preparation and Detection of Enantiomerically Enriched and Configurationally Stable α-Thioalkyllithium Compounds

Sterically demanding and carbanion‐stabilizing substituents like SiMe3 raise the barrier to the configurational inversion of α‐thioalkyllithium compounds. With such substituents these compounds can undergo, for example, electrophilic substitution [Eq. (a)] without changes in configuation. Experiments with deuterated compounds proved that alkyllithium intermediates from primary S‐alkylthiocarbamates are typically not configurationally stable.