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.