TfOH‐Mediated Iodocarbocyclization of Alkenyl Sulfonamides with Iodoarenes

A triflic acid‐mediated iodocarbocyclization of allylic and homoallylic sulfonamides with iodoarenes has been developed for the synthesis of benzo‐fused saturated N‐heterocycles. The combination of iodoarenes and triflic acid provides an efficient electrophilic iodine species for the iodocarbocyclization under ambient reaction conditions. A variety of sulfonamides derived from benzylamines, phenethylamines, and anilines were successfully transformed into the corresponding iodine‐functionalized benzo‐fused N‐heterocycles in good to high yields.