Cobalt(III)-Catalyzed Hydroarylation of Allenes via C–H Activation

The hydroarylation of allenes via C–H activation was achieved with a versatile cationic cobalt(III) catalyst. Step- and atom-economical access to alkenylated heteroarenes is thus provided in a highly chemo- and regioselective manner. Detailed mechanistic studies were conducted, including kinetic studies and Hammett analysis, suggesting the catalytic cycle being initiated with a reversible N-ligand dissociation followed by a kinetically relevant arene C–H activation.