Nickel-Catalyzed Intermolecular Reductive Coupling of Styrene and Its Derivatives with Imines Using Methanol as a Reductant

Catalytic reductive coupling of alkenes with imines has emerged as a powerful tool for amine synthesis via C–C bond formation with the aid of a reductant. However, many of these processes require the use of activated alkenes or hydrosilanes as reductants. Here, we report a nickel-catalyzed intermolecular reductive coupling of styrenes with imines utilizing methanol as a reductant. The key to the success of the reaction is the introduction of MeOLi as an additive, which promotes the ring opening of the aza-nickelacycle intermediate and facilitates hydride transfer from the methoxy group to nickel. This pathway, which involves the reductive transformation of saturated aza-nickelcycles, enables highly linear-selective reductive coupling of alkenes with imines.