Oxidation of Alcohols to Carboxylates with N2O Catalyzed by Ruthenium(II)-CNC Complexes
Air-stable ruthenium(II) complexes based on a picolinederived CNC pincer ligand, [RuH(CNC)(CO)L]X (L = PPh3, X = Br; L = CO, X = BF4), were found to catalyze under basic conditions the oxidation with N2O of a series of alcohols to carboxylates. Both [RuH(CNC)(CO)L]X complexes react readily with stro...
| Authors: | , , , , |
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| Format: | article |
| Status: | Published version |
| Publication Date: | 2025 |
| Country: | España |
| Institution: | Universidad de Sevilla (US) |
| Repository: | idUS. Depósito de Investigación de la Universidad de Sevilla |
| OAI Identifier: | oai:idus.us.es:11441/178835 |
| Online Access: | https://hdl.handle.net/11441/178835 https://doi.org/10.1021/acscatal.5c02021 |
| Access Level: | Open access |
| Keyword: | Nitrous oxide Transfer hydrogenation Alcohols Carboxylates Ruthenium complexes |
| Summary: | Air-stable ruthenium(II) complexes based on a picolinederived CNC pincer ligand, [RuH(CNC)(CO)L]X (L = PPh3, X = Br; L = CO, X = BF4), were found to catalyze under basic conditions the oxidation with N2O of a series of alcohols to carboxylates. Both [RuH(CNC)(CO)L]X complexes react readily with strong bases (tBuOK or KHMDS), giving rise to a Ru(II) complex containing a deprotonated CNC* ligand (when L = PPh3) or a Ru(0)-CNC derivative (for L = CO). Furthermore, the mechanism of the catalytic reaction has been elucidated through density functional theory (DFT) calculations. The catalytic cycle has been shown to proceed through an outer-sphere mechanism comprising four key transformations, which involve Ru(II) intermediates based on the deprotonated CNC* ligand: (i) alkoxide dehydrogenation to yield a Ru(II) hydride complex and an aldehyde molecule, (ii) N2O insertion into the ruthenium− hydride bond to yield a hydroxy ruthenium species and N2, (iii) nucleophilic attack of the hydroxo ligand in the Ru−OH complex to the intermediate aldehyde, and (iv) dehydrogenation of the formed alcoholate to regenerate the catalytically active Ru(II) hydride and produce the carboxylate product. |
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