Articles producció científica> Química Física i Inorgànica

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

  • Datos identificativos

    Identificador: PC:3382
    Autores:
    Ricart, J. M.García-López, D.Civit, M.Vogels, C.Westcott, S.Fernández, E.Carbó, J.
    Resumen:
    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.
  • Otros:

    Autor según el artículo: Ricart, J. M. ; García-López, D.; Civit, M.; Vogels, C. ; Westcott, S. ; Fernández, E. ; Carbó, J.
    Departamento: Química Física i Inorgànica
    Autor/es de la URV: RICART PLA, JOSE MANUEL; García-López, D.; Civit, M.; Vogels, C. ; Westcott, S. ; FERNÁNDEZ GUTIÉRREZ, MARIA ELENA; CARBÓ MARTIN, JORGE JUAN
    Palabras clave: selenoboration stereoselective anti-addition
    Resumen: 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.
    Grupo de investigación: Química Quàntica
    Áreas temáticas: Química Química Chemistry
    Acceso a la licencia de uso: https://creativecommons.org/licenses/by/3.0/es/
    ISSN: 2044-4753
    Identificador del autor: 0000-0002-2610-5535; ; ; ; ; 0000-0001-9025-1791; 0000-0002-3945-6721
    Fecha de alta del registro: 2019-01-25
    Página final: 3628
    Volumen de revista: 8
    Versión del articulo depositado: info:eu-repo/semantics/publishedVersion
    Enlace a la fuente original: https://pubs.rsc.org/en/content/articlelanding/2018/CY/C7CY02295F#!divAbstract
    Programa de financiación: plan; Excelencia; CTQ2016-80328-P plan; Excelencia; CTQ2014-52774-P altres; Grupos consolidados; 2014SGR199
    URL Documento de licencia: https://repositori.urv.cat/ca/proteccio-de-dades/
    DOI del artículo: 10.1039/c7cy02295f
    Entidad: Universitat Rovira i Virgili
    Año de publicación de la revista: 2018
    Página inicial: 3617
    Tipo de publicación: Article Artículo Article
  • Palabras clave:

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