Selective Homogeneous Hydrogenation of Biogenic Carboxylic Acids with [Ru(TriPhos)H]: A Mechanistic Study.
Selective hydrogenation of biogenic carboxylic acids is an important transformation for biorefinery concepts based on platform chemicals. We herein report a mechanistic study on the homogeneously ruthenium/phosphine catalyzed transformations of levulinic acid (LA) and itaconic acid (IA) to the corre...
| Publicado en: | Journal of the American Chemical Society Vol. 133; no. 36; pp. 14349 - 14359 |
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| Autores principales: | , , , , |
| Formato: | Artículo |
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American Chemical Society
9/14/2011
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| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=hlh&AN=66735646&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 66735646 longDbName: Humanities International Complete uiTag: AN controlInfo: bkinfo: jinfo: jid: 00027863 ACS jtl: Journal of the American Chemical Society issn: 00027863 maglogo: N pubinfo: dt: 9/14/2011 vid: 133 iid: 36 pid: 997 pub: American Chemical Society artinfo: ui: 66735646 10.1021/ja2034377 ppf: 14349 ppct: 10 formats: tig: atl: Selective Homogeneous Hydrogenation of Biogenic Carboxylic Acids with [Ru(TriPhos)H]: A Mechanistic Study. aug: au: Geilen, Frank M. A. Engendahl, Barthel Hö1scher, Markus Klankermayer, Jürgen Walter Leitner affil: Inititut für Technische und Makromolekulare Chemie, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany Max-P1ar1ck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim a.d. Ruhr, Germany su: Carboxylic acids Hydrogenation Ruthenium Density functionals Nuclear magnetic resonance sug: subj: Carboxylic acids Hydrogenation Ruthenium Density functionals Nuclear magnetic resonance ab: Selective hydrogenation of biogenic carboxylic acids is an important transformation for biorefinery concepts based on platform chemicals. We herein report a mechanistic study on the homogeneously ruthenium/phosphine catalyzed transformations of levulinic acid (LA) and itaconic acid (IA) to the corresponding lactones, diols, and cyclic ethers. A density functional theory (DFT) study was performed and corroborated with experimental data from catalytic processes and NMR investigations. For [Ru(TriPhos)H] as the catalytically active unit, a common mechanistic pathway for the reduction of the C=O functionality in aldehydes, ketones, lactones, and even free carboxylic acids could be identified. Hydride transfer from the Ru-H group to the carbonyl or carboxyl carbon is followed by protonation of the resulting Ru-O unit via σ-bond metathesis from a coordinated dihydrogen molecule. The energetic spans for the reduction of the different functional groups increase in the order aldehyde < ketone < lactone ≈ carboxylic acid. This reactivity pattern as well as the absolute values are in full agreement with experimentally observed activities and selectivities, forming a rational basis for further catalyst development. pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: Y dt: @attributes: year: 2011 holdings: @attributes: islocal: N |
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