Synthesis and Reactivity of Carboranylsilylene Stabilized Boranes: Construction of Carborane-Fused Silaboracycles

This work describes that a sterically bulky o-carboranylsilylene can significantly enhance the stability of the resultant carboranylsilylene-borane adducts. Removal of one halide from the boron center via salt metathesis reaction initiates immediately the halide migration from the boron to silicon and subsequent aminidate ligand rearrangement from the silicon to boron, resulting in the formation of a new class of o-carborane-fused silaboracycles in very good yields. The associated reaction mechanism is also discussed.