Cyclic amino(carboranyl) silylene: synthesis, structure and reactivity

A carbene-stabilized cyclic amino(carboranyl) silylene has been prepared from the reaction of cyclic amino(carboranyl) chlorosilane with N-heterocyclic carbene via HCl elimination. Its structure has been characterized by single-crystal X-ray analysis and DFT calculations. It is a very strong σ donor and relatively poor π acceptor. It can form a Lewis acid–base adduct with borane and undergo cycloaddition reactions with unsaturated molecules such as diphenylacetylene and benzophenone.