Reactions of Alkynyl-Ruthenium Complexes with the Ketene Dithioacetal, (MeS)₂C=C(CN)₂

Reactions of several alkynyl-ruthenium complexes with the ketene dithioacetal (MeS)(2)C=C(CN)(2) (2) are described. The first examples of metalated 6-alkylthio-6-azafulvenes, Ru{C=CRC-(SMe)=QCN)C=N(SMe)} PPh3)CP [R = Ph (5a), Fc (5b)], were obtained from Ru(C=CR)(PPh3)(2)CP, while Ru(C=CPh)(CO)(PPh3)CP gave dienyl complexes Ru{C(SMe)=CPhC(SMe)=C(CN)(2)}(CO)(PPh3)nCP [n = 1 (8), 0 (9)]. Yields of the azafulvenes were increased under conditions conducive to radical formation. The reaction between 5 and Ru(C=CC=CPh)(PPh3)(2)Cp afforded the alkynyl - dienyl Ru{C(SMe)=C(C CPh)C(SMe)=C(CN)(2)}(PPh3)CP (11) and the dienynyl Ru{C CC(SMe)=CPhC(SMe)=C(CN)(2)}(PPh3)(2)CP (12), formed by formal insertion of either C C triple bond into one C-S bond. The reaction of Ru(C CPh)(PPh3)(2)Cp with dimethyl 2,3-dicyanofumarate (3) afforded diastereomers of the eta(3)-dienyl complex Rut 7{eta(3)-C(CN)(CO2Me)CPhC=C(CN)(CO2Me)}(PPh3)CP (13). XRD structural determinations of 5a, 8, 9, 11, and one diastereomer of 13 are reported.