Dual-Co/Ni-Catalyzed Radical Hydroarylation of 1,3-Enynes: Selective Access to Tetrasubstituted Allenes

Metal hydride hydrogen atom transfer (MHAT) has emerged as a powerful strategy for alkene hydrofunctionalization, offering exceptional control over regio- and chemoselectivity. However, conventional MHAT reactions with 1,3-enynes remain limited to the 1,2-addition pathway. Herein, we report a regioselective 1,4-hydroarylation of 1,3-enynes with various aryl halides enabled by dual cobalt and nickel catalysis. This transformation proceeds through cobalt(III)-H-mediated HAT to the 1,3-enynes, followed by nickel-catalyzed cross-coupling with aryl halides, delivering a wide range of tetrasubstituted allenes in good to excellent yields. This work expands the scope of Co(III)H-mediated radical hydrofunctionalization reactions and offers a modular strategy for constructing valuable, highly substituted allene building blocks.