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 Introduction
2 Origins of the β-Silicon Effect
3 Reactions of Allenylsilanes
4 Reactions of Alkynes
4.1 Propargylsilanes
4.2 Alkynylsilanes
5 Reactions of Alkenes
5.1 Allylsilanes
5.2 Vinylsilanes
6 Conclusions
Key words β-silicon effect - 1,2-silyl migration - carbocations - allenylsilanes - propargylsilanes
- allylsilanes - silylvinylidenes