Rh-Catalyzed Twofold Conjugate Addition of 2-Arylimidazo[1,2- a ]pyridines to p -Quinols To Access Bridged Scaffolds with Three Contiguous Stereocenters.

A Rh(III)-catalyzed annulation of 2-arylimidazo[1,2- a ]pyridines with p -quinols has been realized, leading to bridged heterocycles with three contiguous stereocenters via a twofold conjugate addition. The cascade reaction is diastereoselective and proceeds through a sequential Rh-catalyzed ortho C(sp 2 )-H functionalization of the aryl group of imidazo[1,2- a ]pyridine with p -quinol followed by an intramolecular conjugate addition to provide a series of diverse, novel bridged heterocycles.