Mn- and DMAP-Promoted Formal [3 + 2]-Cycloaddition of Cyanoacetates and Malonates with Vinyl Azides for the Synthesis of α-Quaternary Ene-γ-Lactams

A Mn- and DMAP-promoted [3 + 2]-cycloaddition of cyanoacetates and malonates with vinyl azides was presented, enabling the concise synthesis of α-quaternary ene-γ-lactam. The utility of the catalytic system was demonstrated by the concise synthesis of the natural product sargassumlactam.