Transition-Metal-Catalyzed Cyanochalcogenation of Alkynes with Chalcogenocyanates

Tetrakis(triphenylphosphine)palladium(0) catalyzes the highly regioselective addition of phenyl thiocyanate to terminal alkynes, which attains the simultaneous introduction of thio and cyano groups into the internal and terminal positions of alkynes, respectively. In addition, dicobalt octacarbonyl indicates moderate catalytic activity toward the same cyanothiolation of alkynes with excellent regioselectivity. By using [Co2(CO)8] as the catalyst, novel cyanoselenation of alkynes with phenyl selenocyanate has also been attained in moderate yield with excellent regioselectivity.