Download PDF
Synlett 1995; 1995(6): 579-586
DOI: 10.1055/s-1995-5008
account
© Georg Thieme Verlag, Rüdigerstr. 14, 70469 Stuttgart, Germany. All rights reserved. This journal, including all individual contributions and illustrations published therein, is legally protected by copyright for the duration of the copyright period. Any use, exploitation or commercialization outside the narrow limits set by copyright legislation, without the publisher's consent, is illegal and liable to criminal prosecution. This applies in particular to photostat reproduction, copying, cyclostyling, mimeographing or duplication of any kind, translating, preparation of microfilms, and electronic data processing and storage.

Carbonyl Metal Clusters as Homogeneous Catalysts: Hydrogenation of Alkynes Mediated by Hydridotriruthenium Clusters Containing Bridging N-Donor Ligands

Javier A. Cabeza* , José M. Fernández-Colinas, Angela Llamazares
  • *Instituto de Química Organometálica ”Enrique-Moles”, Facultad de Química, Universidad de Oviedo-CSIC, E-33071 Oviedo, Spain
Further Information

Publication History

Publication Date:
31 December 2000 (online)

  PDF Download  Permissions and Reprints All articles of this category

The face-bridged cluster compounds [Ru3(μ-H)(μ3-ampy)(CO)9], [Ru3(μ3-ampy)(μ, η1:η2-PhC=CHPh)(CO)8], [Ru3(μ-H)(μ3-ampy)(PR3)(CO)8], and [Ru3(μ3-ampy)(μ, η1:η2-PhC=CHPh)(PPh3)2(CO)6] (Hampy = 2-amino-6-methylpyridine) are catalyst precursors for the homogeneous hydrogenation of diphenylacetylene. Stoichiometric reactions related to the catalytic processes, along with spectroscopic and kinetic studies, have demonstrated that these complexes maintain their trinuclear framework during the catalytic reactions. However, the edge-bridged cluster compound [Ru3(μ-H)(μ-dadmb)(CO)9] (Hdadmb = 1,2-diamino-4,5-dimethylbenzene), which is also an efficient promoter for the homogeneous hydrogenation of diphenylacetylene, undergoes fragmentation under the catalytic conditions to give mononuclear catalytic species. In all these cases, the hydrogenation products are cis- (kinetic product) and trans-stilbene (thermodynamic product) and the reactions proceed efficiently under very mild conditions (T ≤ 80 °C, P(H2) ≤ latm). In general, alkynes insert into the hydride-ruthenium bond of hydridotriruthenium carbonyl cluster complexes containing bridging N-donor ligands to give μ,η1:η2-alkenyl derivatives. Most of these alkenyl complexes have been shown to be intermediates or catalyst precursors in/for alkyne hydrogenation reactions under homogeneous conditions.

Cluster catalysis - homogeneous hydrogenation - alkyne hydrogenation - catalysis mechanisms