Catalytic C−H Functionalization Driven by CO as a Stoichiometric Reductant:  Application to Carbazole Synthesis

[reaction: see text] A palladium-catalyzed regioselective C-H bond functionalization driven by CO as the stoichiometric reductant is described. Nitrogen heterocycles, e.g., carbazoles, are accessible in good to excellent yields with use of palladium acetate and 70 psig of carbon monoxide at 140 degrees C.