Old Key Opens the Lock in Carborane: The in Situ NHC-Palladium Catalytic System for Selective Arylation of B(3,6)–H Bonds of o-Carboranes via B–H Activation

An efficient in situ Pd-NHC catalytic system for regioselective arylation of B(3,6)–H bonds of o-carborane has been developed for the first time. A series of symmetric and unsymmetric 3,6-diaryl-o-carboranes anchored with active groups have been synthesized with moderate to good yields under mild conditions. This work offers an efficient protocol for selective activation of B(3,6)–H bonds and has important value in design coupling reactions for selective functionalization of o-carboranes.