Visible Light-Induced Photolysis of Phosphonium Iodides for the Radical Arylthiodifluoromethylation of Isocyanides

A photo-induced charge transfer complexation strategy with phosphonium iodides has been developed to enable arylthiodifluoromethylation reactions of isocyanides. The transformation proceeds via addition of the arylthiodifluoromethyl radical which is generated by photolysis of the arylthiodifluoromethyl phosphonium iodide to the isonitrile group followed by intramolecular cyclization. This strategy provides a convenient, mild, and green approach for the synthesis of arylthiodifluoromethylated phenanthridines and isoquinolines.