Crystalline phosphino(silyl)carbenes that readily form transition metal complexes.

Phosphino(silyl)carbenes are known for their ineptitude to form transition metal complexes. We describe the synthesis of phosphino(silyl)carbenes bearing N-heterocyclic imine groups and show that these isolable, crystalline carbenes readily form stable copper(I) and gold(I) complexes. The solid-state structures of the free carbenes and their transition metal complexes are reported.