Transition metal-free photocatalytic radical annulation of 2-cyanoaryl acrylamides with difluoromethyl radicals to assemble 4-amino-quinolinone derivatives

Abstract

The transformation of an iminyl radical into a primary amine is a challenging task. A practical and green catalytic system to trigger difluoromethyl radicals is highly desired. Herein, we developed a metal-free photocatalytic radical annulation of 2-cyanoaryl acrylamides with [CF₂HPPh₃]⁺Br⁻ to provide 4-amino-quinolinones in moderate to good yields. This protocol utilized an easily obtained and cheap organophotocatalyst and green solvent acetone/H₂O, and had the advantages of simple operation and broad substrate scope.