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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 alquilación aliloides α-selectivas y catalizadas por Cu (I) entre ésteres de fosforotioato y reactivos
Andrew M Lauer1, Farzeen Mahmud, Jimmy Wu
1Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755, USA.
Journal of the American Chemical Society
|May 20, 2011
Resumen
La catálisis del cobre permite la alfa-alquilación regioselectiva de los ésteres de fosforotioato utilizando reactivos de Grignard. Este nuevo método proporciona un enfoque general para el control de la selectividad en las reacciones de sustitución alelica desafiantes.
Área de la Ciencia:
- Química orgánica es la química orgánica.
- La catálisis de la catálisis.
- Metodología sintética de la metodología sintética.
Sus antecedentes:
- El regiocontrole en la alquilación alílica, particularmente favoreciendo la alfa-alquilación con nucleófilos duros, presenta un desafío sintético significativo.
- Los métodos existentes a menudo carecen de generalidad o no proporcionan una alta selectividad para el isómero alfa deseado.
Objetivo del estudio:
- Desarrollar nuevos métodos catalíticos para lograr una alta selectividad alfa-regional en reacciones de alquilación alílica.
- Explorar la utilidad de la catálisis del cobre (I) en la sustitución alelica de los ésteres de fosforotioato.
- Establecer un protocolo simple para mejorar la selectividad alfa a partir de haluros alelicos secundarios.
Principales métodos:
- Reacciones de sustitución aliloide catalizadas por cobre (I) utilizando ésteres de fosforotioato como sustratos.
- Empleando varios reactivos de Grignard para evaluar el alcance y las limitaciones del sistema catalítico.
- Utilizando fosforotioatos de sodio como aditivos en reacciones con haluros alelicos secundarios.
Principales resultados:
- La catálisis de Cu (I) alcanzó una excelente selectividad alfa-regional en la sustitución alelica de ésteres de fosforotioato, independientemente del reactivo de Grignard utilizado.
- Esto representa el primer informe de la alquilación alilica catalizada por Cu de los ésteres de fosforotioato.
- Se desarrolló un protocolo sencillo que utilizaba fosforotioatos de sodio como aditivos, lo que producía una alta selectividad alfa de haluros alelicos secundarios.
Conclusiones:
- La catálisis del cobre (I) ofrece una estrategia poderosa y general para la alfa-alquilación regioselectiva de los ésteres de fosforotioato.
- El protocolo de aditivos desarrollado proporciona un medio eficaz para controlar la selectividad en las alquilaciones alelicas que involucran haluros alelicos secundarios.
- Estos hallazgos avanzan en el campo de la alquilación alílica catalítica, ofreciendo nuevas herramientas para los químicos sintéticos.
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