Kinetics and mechanisms of homogeneous catalytic reactions. Part 4. Hydrogenation of cyclohexanone and 2-cyclohexen-1-one catalysed by the complexes [MH(CO)(NCMe)2(PPh3)2]BF4(M = Ru, Os)
| Autor: | Milagros Mora, Angel González, Merlin Rosales, Navarro J, Ligbel Sánchez, Humberto Soscún, Nidal Nader |
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| Rok vydání: | 2004 |
| Předmět: |
chemistry.chemical_classification
Ketone Metals and Alloys Cyclohexanone chemistry.chemical_element Medicinal chemistry Oxidative addition Ruthenium Catalysis Inorganic Chemistry chemistry.chemical_compound chemistry Catalytic cycle Materials Chemistry Organic chemistry Selective reduction Organometallic chemistry |
| Zdroj: | Transition Metal Chemistry. 29:205-211 |
| ISSN: | 0340-4285 |
| Popis: | Kinetic and mechanistic studies of the homogeneous hydrogenation of cyclohexanone were carried out using the cationic complexes [MH(CO)(NCMe)2(PPh3)2]BF4 (M = Ru, Os) as the catalyst precursors, which were very efficient under mild reaction conditions in 2-methoxyethanol solution. For both complexes, the catalytic hydrogenation of cyclohexanone proceeds according to the rate law r = k[M][H2]. The activation parameters were also calculated, the activation energy for the osmium catalyst being higher than for the ruthenium(I). All experimental data are consistent with a mechanism involving the oxidative addition of hydrogen as the rate-determining step of the catalytic cycle. Finally, the [MH(CO)(NCMe)2(PPh3)2]BF4 complexes were efficient precatalysts for the selective reduction of 2-cyclohexen-1-one to cyclohexanone; the reduction of the CO group of cyclohexanone only begins to take place when the α,β-unsaturated ketone has been consumed. |
| Databáze: | OpenAIRE |
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