Cycloelimination of β-silylethyl sulphoxides: alkene, alkyne, and vinyl-silane-forming reactions

Abstract

The cycloelimination (1)→(3) of trimethylsilyl sulphenate from a β-silylethyl sulphoxide is slightly faster than the corresponding cycloelimination (2)→(3) of sulphenic acid itself. The former type of reaction can be used to form acetylenes [e.g.(24)→(25)]. However, this pathway is only followed when there is no hydrogen on the β-carbon; when there is such a hydrogen, the elimination of sulphenic acid (8)→(10) takes place, because the silyl group substantially speeds up the abstraction of the hydrogen atom adjacent to it.