Skeletal Rearrangements Involving Cyclopropyl- and Alkene-Stabilized Silylium Ions

Abstract

This Account summarizes the fascinating chemistry of cyclopropyl-stabilized silylium ions which are readily available from vinylcyclopropanes (VCPs). Depending on the nucleophilic partner, these reactive intermediates undergo either direct ring opening or ring expansion to nonclassical alkene-stabilized silylium ions. The latter can also be accessed by gold- as well as proton electrophiles from silicon compounds containing unsaturated C–C bonds. All of these reaction cascades can be terminated by C–H or C–C as well as Si–O bond formation. From this, a clearer picture of the versatility of these rather complex chemistry emerges.