Double HydrideTransfer Enabled Substitution of AllHydrogens at α,β-Positions of Cyclic Amines: Access toα,β-Unsaturated Lactams

A one-shot substitution of all hydrogens at the α,β-positions of saturated cyclic amines was achieved. The key feature of this reaction is the sequential involvement of intra- and intermolecular redox processes. When <i>N</i>,<i>O</i>-acetals obtained through an internal redox process were treated with a catalytic amount of Zn(OTf)₂ and an excess amount of benzylidene barbiturates, three key transformations involving intermolecular redox process occurred successively to afford α,β-unsaturated lactams in moderate to good chemical yields.