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Metátesis de acrilato a través del catalizador Grubbs de segunda generación: vías inesperadas habilitadas por un
Gwendolyn A Bailey1, Deryn E Fogg1
1Center for Catalysis Research and Innovation and Department of Chemistry, University of Ottawa, Ottawa, Ontario K1N6N5 Canada.
Journal of the American Chemical Society
|June 2, 2015
Resumen
El catalizador GII de Grubbs puede causar reacciones secundarias inesperadas en la metástasis del acrilato. El ligando de fosfina ataca el acrilato, lo que lleva a la formación de carbanión y la desactivación del catalizador, impactando la síntesis y la despolimerización del polímero.
Área de la Ciencia:
- Química orgánica es la química orgánica.
- Química de Polímeros La Química de Polímeros es la química de los polímeros.
- La catálisis de la catálisis.
Sus antecedentes:
- La metátesis de acrilato ofrece diversas aplicaciones, incluida la síntesis de valiosos ésteres α,β insaturados y la despolimerización de polímeros insaturados.
- El catalizador de Grubbs GII es un catalizador clave en estas transformaciones.
Objetivo del estudio:
- Para investigar reacciones secundarias inesperadas que involucran el catalizador de Grubbs GII en la metátesis de acrilato.
- Para aclarar el mecanismo de estas reacciones secundarias y su impacto en los procesos catalíticos.
Principales métodos:
- Estudios mecanicistas detallados utilizando el catalizador de Grubbs GII.
- Análisis de las vías de reacción, incluida la formación de carbaniones y las reacciones posteriores.
Principales resultados:
- Se observó evidencia del ataque del ligando de la fosfina (PCy3) en la olefina acrilata.
- Este ataque genera un intermediario reactivo de carbanión.
- El carbanión participa en las vías de adición de Michael, abstracción de protones y desactivación de catalizadores.
Conclusiones:
- Reacciones secundarias inesperadas pueden ocurrir con el catalizador de Grubbs GII en la metástesis de acrilato.
- Los complejos metálicos-fosfinos labiles que catalizan reacciones con olefinas con déficit de electrones pueden exhibir una reactividad similar.
- Comprender estas vías es crucial para optimizar la metástasis de acrilato y los procesos catalíticos relacionados.
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