The development of a new method for the assembly of unsymmetrical carbazoles is reported. The strategy involves the selective intramolecular functionalization of an arene C-H bond and the formation of a new arene C-N bond. The substitution pattern of the carbazole product can be controlled by the design of the biaryl amide substrate, and the method is compatible with it variety of functional groups. The utility of the new protocol was demonstrated by the concise synthesis of three natural products from commercially available materials.
“Palladium-Catalyzed Method for the Synthesis of Carbazoles via Tandem C−H Functionalization and C−N Bond Formation”, J. Org. Chem., 2008, 73(19), 7603-7610.