Synthesis of 10 H -indolo[1,2- a ]indol-10-ones via palladium-catalyzed C–H bond activation and difluorocarbene transfer

A Pd-catalyzed annulation between 1-(2-iodophenyl)-1 H -indoles and sodium difluorochloroacetate has been developed to synthesize 10 H -indolo[1,2- a ]indol-10-one derivatives via C–H bond activation and difluorocarbene transfer. Our route enables facile access to the targeted products with various substituents in moderate to high yields. This method features high reactivity, good functional group tolerance, a simple operation procedure, and mild reaction conditions. The reaction can be carried out on a gram scale.