Cu/Pd-Catalyzed Ligand-Controlled Regiodivergent Hydroarylation of Allenes Using Diisobutylaluminum Hydride

We report a ligand-controlled, regiodivergent Cu/Pd-catalyzed hydroarylation of unactivated allenes. The reaction proceeds via Cu-catalyzed hydroalumination with DIBAL-H and subsequent additive-free Pd-catalyzed cross-coupling with aryl bromides. The key feature of this work is the discovery that modulation of the palladium ligand decisively enables complete regiodivergence. Bulky monodentate Xphos ligands promote exclusive γ-selective arylation, while bidentate Josiphos-type ligands switch the pathway to afford α-selective arylation. The method features mild conditions, scalability, and broad utility for synthesizing polysubstituted aromatic compounds.