SYNTHESIS, REACTIVITY AND CATALYTIC ACTIVITY OF [RUH(ETA(1)-OCME(2))(CO)(2)(PPR3I)(2)]BF4

The solvento complex [RuH(eta(1)-OCMe(2))(CO)(2)(PPr3i)(2)]BF4 2, which is an active catalyst fdr the exclusive hydrogenation of phenylacetylene to styrene and the hydrosilylation of the same alkyne to cis-PhCH=CH(SiEt(3)), was prepared by reaction of [Ru(H)Cl(OC)(2)((Pr3P)-P-i)(2)] 1 with AgBF4 in acetone as solvent. The reactivity of 2 has been investigated. This compound reacts with Lewis bases (L) to give [RuH(CO)(2)L(PPr3i)(2)]BF4 [L = H2O 3, MeCN 4, CO 5 or pyrazole (Hpz) 6]. Complex 5 can be deprotonated by KOH to afford [Ru(OC)(3)((Pr3P)-P-i)(2)] 7, while the reaction of 6 with [{Rh(mu-OMe)(diolefin)}(2)] [diolefin = tetrafluorobenzobarrelene (tfbb) or cycloocta-1,5-diene, (cod)] led to heterobinuclear compounds of formula [(OC)(2)((Pr3P)-P-i)(2)Ru(mu-H)(mu-pz)Rh(diolefin)]BF4 (diolefin = tfbb 10 or cod 11), The molecular structure of 11 was determined by an X-ray investigation. Compound 11 crystallises in the orthorhombic space group Fdd2. with cell dimensions a = 28.290(2), b = 22.572(1), c = 23.126(1) Angstrom and Z = 16. The structure was refined to R and R' values of 0.0232 and 0.0258 for 6297 observed reflections. The cation in 11 can be described as a ruthenium-rhodium heterobinuclear species where the metals are connected through a bidentate pyrazolate group and a bridging hydride ligand. The metal-metal distance is 3.1323(3) Angstrom. Complex 2 reacts with HCl to give [RuCl2(CO)(2)(PPr3i)(2)] 12, which can be also prepared by reaction of [RuCl(eta(1)-OCMe(2))(CO)(2)-(PPr3i)(2)]BF4 13 with NaCl. This compound in the presence of Lewis bases affords [RuCl(CO)(2)L(PPr3i)(2)]BF4 (L = H2O 14, MeCN 15, CO 16 or Hpz 17). The reactions of 17 with [{Rh(mu-OMe)(diolefin)}(2)] lead to [(OC)(2)((Pr3P)-P-i)(2)Ru(mu-Cl)(mu-pz)Rh(diolefin)]BF4 (diolefin = tfbb 18 or cod 19). Carbon disulfide, SCNR (R = Me or Ph) and HC=CCO(2)Me, undergo insertion reactions into the Ru-H bond of 2 to give the corresponding insertion products, [Ru(eta(2)-S2CH)(CO)(2)(PPr3i)(2)]BF4 20, [Ru{eta(2)-SN(R)CH}(CO)(2)(PPr3i)(2)]BF4 (R = Me 21 or Ph 22) and [Ru{C[C(O)OMe]=CH2}(CO)(2)-(PPr3i)(2)]BF4 23.