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La borilación C-H catalizada por el iridio de los ciclopropanos
Carl W Liskey1, John F Hartwig
1Department of Chemistry, University of Illinois, Urbana, Illinois 61801, United States.
Journal of the American Chemical Society
|February 21, 2013
Resumen
Este estudio informa de una nueva borilación catalizada por iridio de los ciclopropanos, que funcionaliza selectivamente los enlaces metileno C-H. Los ésteres de ciclopropilboronato resultantes son intermediarios versátiles para la síntesis de varios derivados del ciclopropano.
Área de la Ciencia:
- Química organometálica Química orgánica de los metales.
- La catálisis de la catálisis.
- Síntesis orgánica La síntesis orgánica.
Sus antecedentes:
- Los ciclopropanos son anillos de tres miembros con una reactividad única.
- La funcionalización de los enlaces C-H ofrece rutas sintéticas eficientes.
- El desarrollo de métodos catalíticos selectivos para la modificación del ciclopropano es crucial.
Objetivo del estudio:
- Desarrollar un nuevo sistema catalítico para la boroilación directa de los ciclopropanos.
- Para investigar la selectividad de la reacción de borilación.
- Para demostrar la utilidad sintética de los productos de ciclopropano borilado.
Principales métodos:
- Utilizando catalizadores de iridio, específicamente (η(6) -mes) IrBpin3 o [Ir(COD) OMe]2, en combinación con los ligandos de la fenantrolina.
- Realización de la reacción de borilación en condiciones optimizadas.
- Caracterización de los productos borilados y sus posteriores transformaciones.
Principales resultados:
- Se logró la borilación selectiva de los enlaces C-H de metileno en los ciclopropanos, superando a los enlaces C-H de metina y metil.
- Se observaron elevadas diastereoselectividades cuando se utilizó la 2,9-Me2fenantrolina como ligando.
- Los ésteres de ciclopropilboronato generados se convirtieron con éxito en varios compuestos valiosos, incluidas las sales de trifluoroborato, los ácidos bóricos, los ciclopropilarenos, las ciclopropilaminas y los ciclopropanolos.
Conclusiones:
- La borilación catalizada por iridio desarrollada proporciona un método eficiente y selectivo para la funcionalización de los ciclopropanos.
- Esta metodología amplía la caja de herramientas sintéticas para acceder a diversos derivados del ciclopropano.
- La versatilidad de los ésteres de ciclopropilboronato destaca su importancia como intermediarios sintéticos.
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