Metal-Free Hydrogenation of Imines Catalyzed by B(C₆F₅)₃

Stephan et al. have reported the metal-free hydrogenation of imines catalyzed by B(C₆F₅)₃. According to their results, catalytic transfer hydrogenation of imines, enamines, and N-heterocycles is demonstrated by exploiting the activation of amines by the Lewis acid B(C₆F₅)₃. This method has attracted much attention because it represents a rare example of metal-free transfer hydrogenation and can employ the readily accessible diisopropylamine as the source of hydrogen.