Ligand-controlled NiH-catalyzed regiodivergent hydroalkylation of 2-alkenylazaarenes

A nickel-hydride (NiH)-catalyzed migratory and nonmigratory hydroalkylation reaction of 2-alkenyl azaarenes with alkyl iodines has been established through strategic modulation of N- or P-donor ligands. This method enables the synthesis of diverse β- or γ-branched aromatic N-heterocycles. The mild regiodivergent protocols exhibit wide substrate scope, excellent functional tolerance, and great reaction yield with remarkable regioselectivity. Importantly, deuterium labeling studies reveal NiH-catalyzed interrupted chain-walking mode as the mechanism behind remoted β-selective hydroalkylation reaction—an interesting phenomenon mediated through aromatic imine directing groups.