Halogen-Bond-Promoted Double Radical Isocyanide Insertion under Visible-Light Irradiation: Synthesis of 2-Fluoroalkylated Quinoxalines.

A halogen-bond-promoted double radical isocyanide insertion with perfluoroalkyl iodides is reported. With perfluoroalkyl iodides as halogen-bond donors and organic bases as halogen-bond acceptors, fluoroalkyl radicals can be generated by a visible-light-induced single electron transfer (SET) process. The fluoroalkyl radicals are trapped by o-diisocyanoarenes to give quinoxaline derivatives. This mechanistically novel strategy allows the construction of 2-fluoroalkylated 3-iodoquinoxalines in high yields under visible-light irradiation at room temperature.