The reactions of hydrosilanes with the methoxycarbonyl complexes Cp(L)(CO)MCO2Me(MFe, Ru; LCO,PPh3) and (L)(CO)xMCO2Me(MCo, Mn; LCO, PPh3; x = 3,4, with and without catalysis
| Autor: | Alan R. Cutler, R.J Chiulli, Brian T. Gregg, M DiBiase Cavanaugh |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
Silylation
Chemistry Methyl formate Ligand Organic Chemistry chemistry.chemical_element Manganese Biochemistry Medicinal chemistry Catalysis Inorganic Chemistry Metal chemistry.chemical_compound visual_art Materials Chemistry visual_art.visual_art_medium Organic chemistry Reactivity (chemistry) Physical and Theoretical Chemistry Cobalt |
| Zdroj: | Journal of Organometallic Chemistry. 547:173-182 |
| ISSN: | 0022-328X |
| DOI: | 10.1016/s0022-328x(97)00274-x |
| Popis: | The reactivity of selected organotransition metal methoxycarbonyl complexes towards hydrosilanes differs significantly from their acetyl analogs in that hydrosilation does not occur across the methoxycarbonyl ligand. Only hydrosilane/manganese carbonyl precatalyst systems that had proved to be more active towards the acetyl ligand on Cp(L)(CO)MC(O)CH3 (MFe, Ru; LCO,PPh3, PPh3) reacted with the methoxycarbonyl complexes Cp(CO)2MCO2CH3 (1, MFe; 2, MRu). These reactions involving PhSiH3/2–3% (PPh3)(CO)4MnC(O)CH3 for 1 and 2, or PhMe2SiH/2–3% (CO)5MnCH3 for 1 afforded their η4-cyclopentadiene compounds (η4-C5H6)M(CO)3 (MFe,Ru) plus methoxysilanes. Results with PhMe2SiD/3% (CO)5MnCH3 support exo deuteride transfer to the Cp ligand; a mechanism is proposed. The low reactivity of methoxycarbonyl complexes under hydrosilation catalysis conditions also is consistent with the inactivity of PhSiH3 or Ph2SiH2/Rh(PPh3)3Cl towards 1 or 2 and with the inertness of Cp(PPh3)(CO)FeCO2CH3 and Cp∗(CO)2FeCO2CH3 under all attempted hydrosilation conditions. This diminution of hydrosilane reactivity extends to cobalt and manganese carbonyl methoxycarbonyl complexes (L)(CO)xMCO2CH3 (3, MMn, x = 4, LCO; 4, MCo, x = 3, LPPh3; 5, MCo, x = 3, LCO). Although their acetyl analogs (L)(CO)xMC(O)CH3 are sensitive to hydrosilanes, both 3 and 4 are inert towards PhMe2SiH or Ph2SiH2. Treatment of 5 with PhMe2SiH released methyl formate and left the silyl complex (CO)4CoSiMe2Ph, a result that resembles the hydrogenation chemistry of 5. |
| Databáze: | OpenAIRE |
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