Persistent Dialkylsilanone Generated by Dehydrobromination of Dialkylbromosilanol

摘要

A persistent dialkylsilanone was synthesized by the dehydrobromination of a dialkylbromosilanol with tris(trimethylsilyl)silyl potassium in solution at -80 degrees C: It was characterized by NMR and IR spectroscopy, and was tested in several reactions. In Si-29 NMR spectrum in [D-8]toluene, the signal due to the unsaturated silicon nuclei was observed at 128.7ppm. Reactions of the dialkylsilanone with water and mesitonitrile oxide gave a silanediol and a [2+3] cycloadduct, respectively. The silanone remains intact in [D-8]toluene below -80 degrees C for at least two days, while it undergoes unprecedented isomerization to give a siloxysilene by means of 1,3-silyl migration at higher temperatures.