Transition Metal Mimetic π-Activation by Cationic Bismuth(III) Catalysts for Allylic C–H Functionalization of Olefins Using C═O and C═N Electrophiles

Abstract

The discovery and utilization of main-group element catalysts that behave similarly to transition metal (TM) complexes have become increasingly active areas of investigation in recent years. Here, we report a series of Lewis acidic bismuth(III) complexes that allow for the catalytic allylic C(sp 3 )−H functionalization of olefins via an organometallic complexationassisted deprotonation mechanism to generate products containing new C−C bonds. This heretofore unexplored mode of maingroup reactivity was applied to the regioselective functionalization of 1,4-dienes and allylbenzene substrates. Experimental and computational mechanistic studies support the key steps of the proposed catalytic cycle, including the intermediacy of elusive Bi− olefin complexes and allylbismuth species.