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.