Nickel-Catalyzed 8-Aminoimidazo[1,2-a]pyridine-Assisted C(sp2)–H Alkynylation of (Hetero)arenes via an Inverse Sonogashira Strategy Suitable for Late-Stage Modification

Abstract An efficient and convenient approach for the Ni(II)-catalyzed ortho-C(sp2)–H alkynylation, using 8-aminoimidazo[1,2-a]pyridine (8-AIP) as a directing group in the absence of any ligand and oxidant, is described here. The developed protocol represents an Ni(II)-catalyzed route to a broad spectrum of alkynylbenzamides, ensuring site selectivity and diverse functional group compatibility. Various control experiments were performed to underpin the mechanistic pathway. Moreover, late-stage modifications of the synthesized derivatives are demonstrated to reveal the efficacy of 8-AIP as a useful directing group.