Articles producció científica> Química Física i Inorgànica

Iridium-Catalyzed Asymmetric Hydrogenation with Simple Cyclohexane-Based P/S Ligands: In Situ HP-NMR and DFT Calculations for the Characterization of Reaction Intermediates

  • Identification data

    Identifier: PC:1255
    Authors:
    Montserrat DiéguezOscar PàmiesMARIA BIOSCACarlota Borràs
    Abstract:
    We report a reduced but structurally valuable phosphite/phosphinite-thioether ligand library for the Irhydrogenation of 40 minimally functionalized alkenes, including relevant examples with poorly coordinative groups. We found that enantiomeric excesses are mainly dependent on the substrate structure and on some ligand parameters (i.e., the type of thioether/phosphorus moieties and the configuration of the phosphite group), whereas the substituents of the biaryl phosphite moiety had little impact. By tuning the ligand parameters we were able to find highly selective catalysts for a range of substrates (ee’s up to 99%). These phosphite/phosphinite-thioether ligands have a simple backbone and thus yield simple NMR spectra that reduce signal overlap and facilitate the identification of relevant intermediates. Therefore, by combining HP-NMR spectroscopy and theoretical studies, we were also able to identify the catalytically competent Ir-dihydride alkene species, which made it possible to explain the enantioselectivity obtained.
  • Others:

    Author, as appears in the article.: Montserrat Diéguez Oscar Pàmies MARIA BIOSCA Carlota Borràs
    Department: Química Física i Inorgànica
    URV's Author/s: DIÉGUEZ FERNÁNDEZ, MONTSERRAT PAMIES OLLÉ, OSCAR MARIA BIOSCA BORRÀS NOGUERA, CARLOTA
    Keywords: reaction intermediates asymmetric catalysis iridium
    Abstract: We report a reduced but structurally valuable phosphite/phosphinite-thioether ligand library for the Irhydrogenation of 40 minimally functionalized alkenes, including relevant examples with poorly coordinative groups. We found that enantiomeric excesses are mainly dependent on the substrate structure and on some ligand parameters (i.e., the type of thioether/phosphorus moieties and the configuration of the phosphite group), whereas the substituents of the biaryl phosphite moiety had little impact. By tuning the ligand parameters we were able to find highly selective catalysts for a range of substrates (ee’s up to 99%). These phosphite/phosphinite-thioether ligands have a simple backbone and thus yield simple NMR spectra that reduce signal overlap and facilitate the identification of relevant intermediates. Therefore, by combining HP-NMR spectroscopy and theoretical studies, we were also able to identify the catalytically competent Ir-dihydride alkene species, which made it possible to explain the enantioselectivity obtained.
    Research group: Organometàl.lics i Catàlisi Homogènia
    Thematic Areas: Chemistry Química Química
    licence for use: https://creativecommons.org/licenses/by/3.0/es/
    ISSN: 0276-7333
    Author identifier: 0000-0002-8450-0656 0000-0002-2352-8508 n/a n/a
    Record's date: 2015-11-18
    Last page: 5334
    Journal volume: 34
    Papper version: info:eu-repo/semantics/acceptedVersion
    Link to the original source: https://pubs.acs.org/doi/10.1021/acs.organomet.5b00790
    Licence document URL: https://repositori.urv.cat/ca/proteccio-de-dades/
    Article's DOI: 10.1021/acs.organomet.5b00790
    Entity: Universitat Rovira i Virgili
    Journal publication year: 2015
    First page: 5321
    Publication Type: Post-print
  • Keywords:

    Catàlisi asimètrica
    Iridi
    reaction intermediates
    asymmetric catalysis
    iridium
    Chemistry
    Química
    Química
    0276-7333
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