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.