Synthesis of Pyrrole-Annulated Heterocycles through Copper-Catalyzed Site-Selective Dehydrogenative Cross-Coupling

A method for the Cu-catalyzed, intramolecular dehydrogenative cross-coupling of 3-substituted and 3,4-disubstituted pyrrole-azole systems was developed. The C-H bond in the C2 position was site-selectively activated over the C-H bond in the C5 position of unsymmetrically substituted pyrroles, and the six- and seven-membered annulated pyrrole products were directly accessed in moderate to good yields.