Palladium-Catalyzed Multi-Component Reactions of N-Tosylhydrazones, 2-Iodoanilines and CO2 towards 4-Aryl-2-Quinolinones

A palladium-catalyzed three-component reaction between N-tosylhydrazones, 2-iodoanilines and atmospheric pressure CO2 was developed whereby a tandem carbene migration insertion/lactamization strategy afforded 4-aryl-2-quinolinones in moderate to good yields. Notably, a wide range of functional groups were tolerated in this procedure. This protocol features the simultaneous formation of four novel bonds; two C-C, one C=C and one C-N (amide), representing an efficient methodology for incorporation of CO2 into heterocycles.