Mechanistic studies of fluoride-promoted silicon elimination in β-benzotriazolyl-β-aryl-γ-ketosilanes

Abstract

Vicinal elimination of trimethylsilyl and benzotriazolyl groups from 2-benzotriazolyl-2-aryl-3-ketopropylsilanes forms, along with the expected 1,1-disubstituted ethylenes, significant amounts of the corresponding chalcones. A study of this transformation by carbon labeling suggests the intermediate formation of cyclopropanes. Stabilizing/destabilizing (electron-donor/acceptor) para-substituents on the aryl group affect the product distribution of the elimination in a manner consistent with the proposed mechanism.