Formation and reactions of lithium ester silenolates: Silicon analogues of lithium ester enolates

Treatment of cyclohexyl, adamantyl, and benzyl tris(trimethylsilyl)silanecarboxylates with tris(trimethylsilyl)silyllithium afforded the corresponding lithium ester silenolates by Li-Me3Si exchange. The lithium ester silenolates thus prepared reacted readily with electrophiles including water, alkyl halides, and chlorosilanes to produce Si-substituted products. Oxidative coupling of the lithium ester silenolates with palladium dichloride gave polysilane-1,2-dicarboxylates. With mesitaldehyde, a lithium ester silenolate produced products arising from addition of the ester silenolate across the carbonyl bond of the aldehyde.