A diastereomerically enriched, dimeric organolithium compound and the stereochemical course of its transformations.

A dimeric α-silylated ethyllithium compound is presented featuring stereogenic metalated carbon centres with defined configurations. It can be generated by diastereoselective deprotonation of the corresponding ethylsilane. Reaction with Me(3)SnCl proceeds under inversion and the transfer of the stereoinformation is possible with dr's of up to 97:3.

A monolithiated and its related 1,3-dilithiated allylsilane: syntheses, crystal structures, and reactivity.

Treatment of Me2Si(CH2CH=CH2)(CH2NC5H10) with 1 or 2 equiv of t-BuLi afforded the mono- or dilithiated allylsilanes, which crystallize as a tetramer and a hexamer from pentane. The product selectivity in trapping reactions is influenced by the ability of both the solvent and the electrophile to coordinate the lithium center.