191718-66-8Relevant academic research and scientific papers
Mononuclear ruthenium complexes containing two different phosphines in trans position: II. Catalytic hydrogenation of C{double bond, long}C and C{double bond, long}O bonds
Salvi, Luca,Salvini, Antonella,Micoli, Francesca,Bianchini, Claudio,Oberhauser, Werner
, p. 1442 - 1450 (2007/10/03)
Bis(acetate) ruthenium(II) complexes of the general formula Ru(CO)2(OAc)2(PnBu3) [P(p-XC6H4)3] (OAc = acetate, X = CH3O, CH3, H, F or Cl), containing different phosphine ligands trans to PnBu3, have been employed as catalyst precursors for the hydrogenation of 1-hexene, acetophenone, 2-butanone and benzylideneacetone. For comparative purposes, analogous reactions have been performed using the homodiphosphine precursors Ru(CO)2(OAc)2(PnBu3)2 and Ru(CO)2(OAc)2(PPh3)2. The catalytic activity of the heterodiphosphine complexes depends on the basicity of the triarylphosphine trans to PnBu3 as this factor controls, inter alia, the rate of formation of hydride(acetate), Ru(CO)2(H)(OAc)(PnBu3)[P(p-XC6 H4)3], or dihydride, Ru(CO)2(H)2(PnBu3)[(p-XC 6H4)3], complexes, by hydrogenation of the bis(OAc) precursors. The catalytic hydrogenation of the C{double bond, long}C double bond is best accomplished by homodiphosphine dihydride catalysts, while heterodiphosphine monohydrides are more efficient catalysts than the homo- and heterodiphosphine dihydrides for the reduction of the keto C{double bond, long}O bond.
The reaction of Ru(CO)2(MeCO2)2(PR3)2 or Ru2(CO)4(MeCO2)2(PR 3)2 [R = Bu, Ph] with H2 in the presence of Na2CO3: A stoichiometric carbon dioxide activation
Frediani, Piero,Faggi, Cristina,Salvini, Antonella,Bianchi, Mario,Piacenti, Franco
, p. 141 - 149 (2008/10/08)
The hydrogenolysis of the acetato group by molecular hydrogen in phosphine-substituted ruthenium(I) and (II) carbonyl carboxylates has been reinvestigated in the presence of Na2CO3 at various temperatures. From mononuclear complexes such as Ru(CO)2(MeCO2)2(PR3)2, the intermediate hydrido-acetato complex HRu(CO)2(MeCO2)(PRO3)2 has been identified among the products formed working at low temperature. In the case of the binuclear complexes Ru2(CO)4(MeCO2)2(PR2)2 the products obtained at the lowest reaction temperature are H4Ru4(CO)9(PR3)3, H4Ru4(CO)8(PR3)4 and H2Ru(CO)2(PR3)2. The complex H4Ru4(CO)9(PR3)3 is formed from H4Ru4(CO)8(PR3)4 and CO produced from carbon dioxide by the reverse water gas shift reaction catalysed by ruthenium complexes: |Ru| CO2 + H2 ? CO + H2O Carbon dioxide arises from the reaction between Na2CO3 and acetic acid. Several tests support the involvement of the ruthenium-catalysed reverse water gas shift reaction. At higher temperatures phosphido ruthenium complexes are formed. The same products are obtained in the absence of carbon dioxide.
