Copper-Catalyzed Tandem Reaction of Isocyanides with N-(2-Haloaryl)propiolamides for the Synthesis of Pyrrolo[3,2-c]quinolin-4-ones

The copper-catalyzed tandem reaction of isocyanides with N-(2-haloaryl)propiolamides is very efficient for the synthesis of pyrrolo[3, 2-c]quinolin-4-ones. Highly reactive cyclic organocopper intermediates were proposed to be generated in the copper-catalyzed formal [3 + 2] cycloaddition reaction of isocyanides with triple bonds. Intramolecular trapping of the organocopper intermediates can lead to aryl C–C bond formation, which offered an efficient method for constructing fused pyrrole structures.