Some ruthenium complexes derived from 1,4-diethynylbenzene: molecular structure of Ru{eta(3)-C[=C(CN)(2)]C(C6H4C equivalent to CH-4)=C(CN)(2)}(PPh3)Cp

Reactions of Ru(C=CC6H4C=CR-4)(PPh3)(2)Cp [R = SiMe3 (1), H (3)] are descri bed. With Co-2(CO)(8) reactions occur at the C=C triple bond furthest from the ruthenium centre; in contrast, tetracyanoethene gave Ru{eta(3)-C[=C(CN) (2)]C(C6H4C=CR-4)=C(CN)(2)}(PPh3)Cp (R = SiMe3, H), the molecular structure of the latter being determined. Protonation or methylation of 3 occurs at Cg to give the expected vinylidene complexes. With 3, metallation (LiBu), S onogashira and oxidative coupling reactions were demonstrated. Coupling wit h appropriate metal substrates gave a variety of complexes containing RuC=C C6H4C=CM (M = W, Rh, Ir, Pt, Au, Hg) moieties. (C) 1999 Elsevier Science S. A. All rights reserved.