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Mizoroki-Heck Cross-coupling Reactions Catalyzed by Dichloro{bis[1,1',1''-(phosphinetriyl)tripiperidine]}palladium Under Mild Reaction Conditions
Published on: March 20, 2014
Reacciones de Heck de olefinas electrónicamente no sesgadas operacionalmente simples y altamente selectivas para el
Erik W Werner1, Matthew S Sigman
1Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, USA.
Journal of the American Chemical Society
|June 2, 2011
Resumen
Este estudio introduce una nueva reacción de Heck catalizada por paladio para sintetizar productos de (E) estirenilo. El método utiliza condiciones suaves y disolvente DMA, crucial para una alta selectividad y rendimiento en la síntesis orgánica.
Área de la Ciencia:
- Química orgánica es la química orgánica.
- La catálisis es la catálisis.
- Metodología sintética de la metodología sintética.
Sus antecedentes:
- La reacción de Heck es una herramienta vital en la síntesis orgánica para la formación de enlaces C-C.
- Lograr una alta selectividad, especialmente para los isómeros (E), sigue siendo un desafío con diversos sustratos de olefinas.
- Las reacciones catalizadas por paladio son ampliamente utilizadas, pero requieren condiciones optimizadas para la eficiencia y la selectividad.
Objetivo del estudio:
- Desarrollar condiciones simples, suaves y eficientes para una reacción de Heck catalizada por el paladio (0).
- Para lograr altos rendimientos y selectividad para los productos de (E) estirenilo.
- Investigar el papel del disolvente y el catalizador en la selectividad de la reacción.
Principales métodos:
- Utilizó un catalizador de paladio (((0) para la reacción de Heck.
- Se emplea la dimetilacetamida (DMA) como un disolvente σ-donante.
- Substratos de olefinas sin sesgo electrónico investigados con varios grupos funcionales.
- Se llevaron a cabo estudios mecanicistas preliminares para comprender los determinantes de la selectividad.
Principales resultados:
- Se obtienen altos rendimientos y selectividad para los productos de (E) estirenilo.
- Demostró el papel crucial del disolvente DMA en la promoción de una alta selectividad.
- Se identificó que el catalizador distingue los β-hidrógenos en función de su carácter hidrídico.
Conclusiones:
- Desarrolló una reacción de Heck catalizada por Pd(0) robusta y eficiente para sintetizar compuestos de (E) estirenilo.
- Destacó la importancia de la elección del disolvente (DMA) para lograr una alta estereoselectividad.
- Proporcionó conocimientos mecanicistas sobre el comportamiento del catalizador, diferenciándolo de las condiciones oxidativas catalizadas por Pd (II).
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