Mechanistic Aspects of Hydrosilane/Potassium tert-Butoxide (HSiR3/KO tBu)-Mediated Reactions

Abstract

The hydrosilane/potassium tert-butoxide reagent system has attracted significant attention over the last 5 years since the discovery of its ability to silylate heteroarene C-H bonds. Numerous useful HSiR3/KOtBu-mediated transformations are now known, including silylation of sp, sp2, and sp3 C-H bonds, reductive cleavage of C-O, C-S, and C-N bonds, reduction of polycyclic arenes, and hydrosilylation and polymerization of styrenes. This mini-review surveys the rich diversity of reaction mechanisms, both ionic and free radical and including hydride transfer, H atom transfer, and electron transfer, that have been uncovered during recent studies on the HSiR3/KOtBu reagent system. Several mechanistic phenomena that remain to be explained are also highlighted.