Direct palladium-catalyzed C-3 alkynylation of indoles

The direct palladium-catalyzed coupling reaction of indoles with alkynyl bromides was described in this paper. In the presence of catalytic amount of PdCl2(PPh3)2 and 2.0 equiv. NaOAc, the coupling reaction of indoles with alkynyl bromides proceeded smoothly at 50 °C to give the corresponding 3-alkynylindoles with high regioselectivity in good to excellent yields.