Metal‐Free Aminoiodination of Alkynes Under Visible Light Irradiation for the Construction of a Nitrogen‐Containing Eight‐Membered Ring System

A method for the synthesis of dihydrodibenzo[c,e]azocine derivatives via a regioselective intramolecular aminoiodination of alkynes under visible light irradiation has been developed. This protocol uses a combination of iodine and hypervalent iodine to realize a sulfonamidyl radical, followed by intramolecular addition to alkyne to form a vinyl radical. Subsequent trapping of iodine radical affords an 8‐membered heterocycle. Applications of the obtained iodinated 8‐membered heterocycles in the Suzuki‐Miyaura coupling and deiodination are also demonstrated.