Cobaltaelectro-catalyzed oxidative allene annulation by electro-removable hydrazides

An efficient C–H/N–H functionalization with allenes was enabled via versatile electro-oxidative cobalt catalysis. Thus, electrochemical C–H activations were accomplished with high levels of chemoselectivity and regioselectivity in an operationally simple undivided cell setup. The user-friendly nature of this protocol was highlighted by excellent functional group tolerance, an electro-reductive removable hydrazide directing group and easy scalability. Experimental mechanistic studies were indicative of a facile BIES C–H cobaltation event.