The last impregnable fortress, amide fell

Amides are ubiquitous and abundant in nature and our society, but are very stable and reluctant to salt-free, catalytic chemical transformations. Through the activation of a “sterically confined bipyridine–ruthenium (Ru) framework (molecularly well-designed site to confine adsorbed H2 in)” of a precatalyst, catalytic hydrogenation of inactivated amides including formamides through polyamide is achieved. Both C=O bond and C–N bond cleavage of a lactam became also possible by diverse activation of a single Ru precatalyst. That is, catalyst diversity is induced by activation and stepwise multiple hydrogenation of a single precatalyst when the conditions are varied. The versatile catalysts have different structures and different resting states for multifaceted amide hydrogenation, but the common structure produced upon reaction with H2, which catalyzes hydrogenation, seems to be “H–Ru–N–H.” Hydrogenation of CO2 derivative, N,N-dimethylformamide (DMF), also proceeded far more smoothly than preceding methods, giving full conversion of DMF under mild reaction conditions. Since the chemical immobilization of CO2 as DMF has well been investigated, a combination of the previous and present methods could provide an alternative route that benefits the methanol economy.