Christian Mechtler

POLYSILYLDIANIONS : SYNTHESIS AND REACTIVITY

Abstract Reaction of α,ω-bis[tris(trimethylsilyl)silyl]alkanes with one equivalent of potassium tert -butoxide resulted in clean formation of mono-potassium silyl anions. Addition of another equivalent of the transmetallating agent led to the formation of the di-potassium compounds. Partial hydrolysis of the di-potassium compounds induced an intramolecular reaction yielding a cyclic silyl potassium compound.

On some reactions of undecamethylcyclohexasilanyl-substituted silanes

Abstract A number of undecamethylcyclohexasilanyl-substituted silanes have been prepared employing a salt elimination reaction between undecamethylcyclohexasilanyl potassium and several silyl halides or triflates. This method provides access to compounds with one or two undecamethylcyclohexasilanyl units attached to one silicon atom. Several attempts to introduce a third ring failed, resulting in formation of bis(undecamethylcyclohexasilanyl). An alternative approach to the substance class using silyl anions and undecamethylcyclohexasilanyl bromide was also developed. The molecular structure of bis(undecamethylcyclohexasilanyl)methylsilane was determined by X-ray crystallography.

Cyclosilylanions from Dianionic Precursors

Oligosilylanions can easily be prepared by cleavage of a Si-SiMe3 bond with tBuOK in THF, if the central silicon is stabilized by at least two -SiR3 or phenyl substituents [1]. Use of α,ω-alkylidene bridged oligosilanes leads to formation of silyldianions [2]. Reaction of the dipotassium compounds with equimolar amounts of water results in loss of trimethylsilane accompanied by formation of cyclic silylanions.