Manifestation of the β-Silicon Effect in the Reactions of Unsaturated Systems Involving a 1,2-Silyl Shift

Abstract

Many chemical transformations of organosilicon compounds proceed due to the capability of silyl substituents to stabilize a positive charge in its β-position. This short review provides an overview of the present understanding of the β-silicon effect and focusses on the synthetic applications of 1,2-silyl shifts resulting from non-vertical stabilization of alkylcarbenium ions and vinyl cations. The reactions of silicon containing unsaturated starting materials, alkenes, allenes, and alkynes, involving β-silyl group stabilized cationic intermediates, transition metal carbenes, or vinylidene complexes will be discussed.1 Introduction2 Origins of the β-Silicon Effect3 Reactions of Allenylsilanes4 Reactions of Alkynes4.1 Propargylsilanes4.2 Alkynylsilanes5 Reactions of Alkenes5.1 Allylsilanes5.2 Vinylsilanes6 Conclusions