Photoinduced Radical Cyclization of 1,6‐Diynes: Rapid Access to Highly Substituted Carbocyclic and Heterocyclic Compounds

Abstract We have developed photoinduced sulfonyl radical‐triggered cyclization of 1,6‐dynes without metals, oxidants, or additives. During the reaction, three new bonds are formed (−SO 2 −C, C−C, and C−I/C−Se−) under mild conditions, with excellent selectivity. The conversion is temporally and atomically economical and is easy to handle even on a gram scale. Detailed mechanistic studies showed that the reaction proceeds via a radical pathway. Subsequent synthetic transformations of the new products produced various substituted compounds. Importantly, we observed an unprecedented and selective C−C single bond cleavage with boronic acid insertion under Suzuki reaction conditions. magnified image