A rhodium(III)-catalyzed tunable coupling reaction of indole derivatives with alkylidenecyclopropanes via C–H activation

We herein report a rhodium(III)-catalyzed cross coupling of indole derivatives with alkylidenecyclopropanes (ACPs) in the presence of KCl, affording the alkene products exclusively with E-selectivity via C–H bond activation. The beta-H elimination to afford the conjugated diene derivatives has been suppressed by the addition of KCl. A plausible reaction mechanism has been proposed along with derivatization of the obtained product to demonstrate the practical usefulness of this synthetic protocol.