Chelation-assisted Rh(III)-catalyzed C2-selective oxidative C-H/C-H cross-coupling of indoles/pyrroles with heteroarenes

The chelation-assisted strategy has been endowed with some novel functions in the Rh(III)-catalyzed dehydrogenative coupling of indoles/pyrroles with heteroarenes. While the reaction conditions used are rather common, the strategy can close the homo-coupling pathway of each coupling partner, and dramatically extend substrate scope along with the exclusive indole or pyrrole C2-site selectivity. This is the first example describing that a catalytic system allows the oxidative C-H/C-H hetero-coupling not only between two electron-rich heteroarenes but also between electron-deficient and electron-rich heteroarenes, showing a further beneficial aspect of the Rh(III) catalysis.