Transsilylation of O-trimethylsilyl derivatives of α-dimethylaminoketones by chloro(chloromethyl)dimethylsilane

Abstract

Reaction of O-trimethylsilyl (O-TMS) derivatives of α-dimethylamino ketones with chloro(chloromethyl)dimethylsilane led to the formation of six-membered heterocyclic compounds with tetracoordinated silicon atom - 3,4-dihydro-2H-1,4,2-oxazasilin-4-ium chlorides. The exchange reactions of 2,2,4,4-tetramethyl-6-phenyl-3,4-dihydro-2H-1,4,2-oxazasilin-4-ium chloride were examined with Me3SiI and NaBPh4 and the corresponding iodide or tetraphenylborate of 2,2,4,4-tetramethyl-6-phenyl-3,4-dihydro-2H-1,4,2-oxazasilin-4-ium were isolated. 2,2,4,4-Tetramethyl-6-phenyl-3,4-dihydro-2H-1,4,2-oxazasilin-4-ium chloride easy reacts with MeOH to give N-((methoxydimethylsilyl)methyl)-N,N-dimethyl-2-oxo-2-phenylethanaminium chloride. The structure of synthesized compounds 10–15 was proved by multinuclear NMR spectroscopy, 11 was also characterised by X-ray crystallography.