Tris(trimethylsilyl)methyl]lithium: An alkyllithium compound of unusual stability

Abstract

Tris(trimethylsilyl)methane readily undergoes metallation when treated with methyllithium in a mixture of tetrahydrofuran and diethyl ether, and the [tris(trimethylsilyl)methyllithium produced is remarkably stable in tetrahydrofuran. The ease of formation and the stability of the organolithium compound may be associated with stabilization of the carbanion (Me 3Si) 3C − by delocalization of the lone pair of electrons into the d-orbitals of the silicon atom. The organolithium compound can also be obtained by treatment of tris(trimethylsilyl)methyl chloride with lithium, methyllithium, or the n-butyllithium N,N,N′,N′-tetramethylethylenediamine complex. It couples normally with the halides MeI, Me 3SiCl, Me 2HSiCl, Me 3GeBr, and Me 3SnCl, and gives the new acid (Me 3Si) 3CCO 2H on carbonation.