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Arilación directa catalizada por el paladio de los ciclopropenos
Stepan Chuprakov1, Michael Rubin, Vladimir Gevorgyan
1Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street Chicago, Illinois 60607-7061, USA.
Journal of the American Chemical Society
|March 18, 2005
Resumen
La catálisis directa de paladio permite una síntesis eficiente de ciclopropenos tetrasubstituidos, incluidas las formas no racemicas anteriormente inaccesibles. Esta transformación de tipo Heck ofrece una nueva ruta a los complejos derivados del ciclopropeno.
Área de la Ciencia:
- Química orgánica es la química orgánica.
- La catálisis de la catálisis.
- Metodología sintética de la metodología sintética.
Sus antecedentes:
- Los ciclopropenos son hidrocarburos cíclicos tensados con una reactividad única.
- Los métodos existentes para sintetizar ciclopropenos sustituidos, en particular los métodos asimétricos, tienen limitaciones.
- Las reacciones de acoplamiento cruzado catalizadas por paladio son potentes herramientas en la síntesis orgánica.
Objetivo del estudio:
- Desarrollar un nuevo método para la arilación directa y la heteroarilación de los ciclopropenos.
- Para lograr una síntesis eficiente de ciclopropenos altamente sustituidos, incluidos los enriquecidos enantioméricamente.
- Para explorar el camino mecanicista de esta transformación.
Principales métodos:
- Reacciones directas de arilación y heteroarilación catalizadas por paladio utilizando sustratos de ciclopropeno.
- Empleando varios haluros de arilo y heteroarilo como socios de acoplamiento.
- Realización de estudios mecanicistas para dilucidar la vía de reacción.
Principales resultados:
- Demostró los primeros ejemplos de arylación y heteroarylación directa catalizada por paladio de ciclopropenos.
- Con éxito sintetizó una variedad de ciclopropenos tetrasubstituidos.
- Se obtienen ciclopropenos no racémicos, que no son accesibles a través de las técnicas actuales de ciclopropenación asimétrica.
- Las investigaciones mecánicas indican una vía electrofílica característica de las reacciones de tipo Heck.
Conclusiones:
- Se ha establecido una nueva y eficiente vía sintética para los ciclopropenos tetrasubstituidos y no racémicos.
- El método desarrollado catalizado con paladio supera las limitaciones de las estrategias de ciclopropenación asimétrica existentes.
- La transformación se lleva a cabo a través de un mecanismo electrófilo de tipo Heck.
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