An efficient method for the asymmetric synthesis of 4-imidazolidinones via an iodine-catalyzed intramolecular N–H/C­(sp3)–H activation of readily available and abundant feedstocks, amino acids, and amines is described. The reaction proceeded under visible light irradiation to afford a variety of 4-imidazolidinone derivatives under mild conditions in moderate to excellent yields. Secondary and tertiary C­(sp3)–H bonds were aminated, and various functional groups were tolerated.

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.