Metal Additive-Free Iodine-Promoted Reorganization of Ynamide-Ynes and Stereoselective 1,2-Diiodination

We report a metal additive-free iodine-promoted one-step structural reorganization of ynamide-ynes and simultaneous stereoselective 1,2-diiodination of the migrated alkyne to form stereospecific tetrasubstituted alkenyl diiodo-tethered indoles (E-isomer). Molecular iodine is cost effective, user friendly, less toxic, commercially available, and easy to handle. The key features of the reaction include metal-and additive-free environment, selectivity, structural reorganization, mild reaction conditions, simple workup, and gram-scale synthesis. This transformation generates multiple bonds [nitrogen (N)-carbon (C)sp2, Csp2-Csp2, 2 Csp2-iodine (I)] via N-Csp bond cleavage in ynamide-ynes.