Sulfur-Directed C-Selective Alkenylation of Indoles under Rhodium Catalysis.

Regioselective direct functionalization of an indole benzenoid fragment has been a significant challenge because of its inherently lower reactivity. In this report, we introduce a Rh-catalyzed C-selective alkenylation of indole derivatives using a new sulfur directing group -SCy. A notable feature of this system is that the directing group is readily installed to the indoles and easily removed after the catalysis under mild conditions.