Articles producció científica> Química Física i Inorgànica

Understanding the mechanism of transition metalfree anti addition to alkynes: the selenoboration case

  • Dades identificatives

    Identificador: PC:3382
    Autors:
    Ricart, J. M.García-López, D.Civit, M.Vogels, C.Westcott, S.Fernández, E.Carbó, J.
    Resum:
    The stereoselective anti-addition of selenoboranes to α,β-acetylenic esters and amides was achieved in a transition metal-free context using catalytic amounts of PCy3. The reaction provides anti-3,4- selenoboration with concomitant delivery of α-vinyl selenides by protodeboronation with MeOH. Interestingly, in the absence of phosphine the selenoboration switches towards the formation of β-vinyl selenides. Theoretical calculations rationalize the regio- and stereoselectivity of the reaction by discovering a new mechanism for the anti-3,4-selenoboration. While the selenoborane is activated via the “push–pull” effect of B, the phosphine interacts with the β position of the alkynoate switching the polarity of the triple bond and favoring 1,3-selenoboration which provides the α-addition of the selenyl group. Then, the autocatalytic action of a second selenoborane reagent, which coordinates to the phosphorus ylide intermediate, determines the stereoselectivity and completes the catalytic process. Finally, the comparison of selenoborane reagents with diboranes and silaboranes, which have exhibited analogous reactivity, shows that the selenium moiety has a larger nucleophilic character favoring the performance of the reaction under mild conditions.
  • Altres:

    Autor segons l'article: Ricart, J. M. ; García-López, D.; Civit, M.; Vogels, C. ; Westcott, S. ; Fernández, E. ; Carbó, J.
    Departament: Química Física i Inorgànica
    Autor/s de la URV: RICART PLA, JOSE MANUEL; García-López, D.; Civit, M.; Vogels, C. ; Westcott, S. ; FERNÁNDEZ GUTIÉRREZ, MARIA ELENA; CARBÓ MARTIN, JORGE JUAN
    Paraules clau: selenoboration stereoselective anti-addition
    Resum: The stereoselective anti-addition of selenoboranes to α,β-acetylenic esters and amides was achieved in a transition metal-free context using catalytic amounts of PCy3. The reaction provides anti-3,4- selenoboration with concomitant delivery of α-vinyl selenides by protodeboronation with MeOH. Interestingly, in the absence of phosphine the selenoboration switches towards the formation of β-vinyl selenides. Theoretical calculations rationalize the regio- and stereoselectivity of the reaction by discovering a new mechanism for the anti-3,4-selenoboration. While the selenoborane is activated via the “push–pull” effect of B, the phosphine interacts with the β position of the alkynoate switching the polarity of the triple bond and favoring 1,3-selenoboration which provides the α-addition of the selenyl group. Then, the autocatalytic action of a second selenoborane reagent, which coordinates to the phosphorus ylide intermediate, determines the stereoselectivity and completes the catalytic process. Finally, the comparison of selenoborane reagents with diboranes and silaboranes, which have exhibited analogous reactivity, shows that the selenium moiety has a larger nucleophilic character favoring the performance of the reaction under mild conditions.
    Grup de recerca: Química Quàntica
    Àrees temàtiques: Química Química Chemistry
    Accès a la llicència d'ús: https://creativecommons.org/licenses/by/3.0/es/
    ISSN: 2044-4753
    Identificador de l'autor: 0000-0002-2610-5535; ; ; ; ; 0000-0001-9025-1791; 0000-0002-3945-6721
    Data d'alta del registre: 2019-01-25
    Pàgina final: 3628
    Volum de revista: 8
    Versió de l'article dipositat: info:eu-repo/semantics/publishedVersion
    Enllaç font original: https://pubs.rsc.org/en/content/articlelanding/2018/CY/C7CY02295F#!divAbstract
    Programa de finançament: plan; Excelencia; CTQ2016-80328-P plan; Excelencia; CTQ2014-52774-P altres; Grupos consolidados; 2014SGR199
    URL Document de llicència: https://repositori.urv.cat/ca/proteccio-de-dades/
    DOI de l'article: 10.1039/c7cy02295f
    Entitat: Universitat Rovira i Virgili
    Any de publicació de la revista: 2018
    Pàgina inicial: 3617
    Tipus de publicació: Article Artículo Article
  • Paraules clau:

    Metalls de transició
    Bor
    Estereoquímica
    selenoboration
    stereoselective anti-addition
    Química
    Química
    Chemistry
    2044-4753
  • Documents:

  • Cerca a google

    Search to google scholar