Platinum Iodide-Catalyzed Three-Component Cascade Cycloaddition Reactions between γ-Aminoalkynes and Electron-Deficient Alkynes.

Herein, we report a protocol for PtI-catalyzed three-component cascade cycloaddition reactions between γ-aminoalkynes and electron-deficient alkynes to afford highly substituted cyclohexadiene--pyrrolidines in good yields. On the basis of the results of the control experiments and density functional theory calculations, we present a plausible mechanism that proceeds via two key intermediates. The overall transformation involves the cleavage and formation of multiple C-C and C-N bonds and a previously unreported reaction mode of a seven-membered nitrogen heterocyclic intermediate.