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Acoplamiento cruzado descarbonilativo de anhídridos cíclicos: introducción de la estereoquímica en un carbono sp3 en
Erin M O'Brien1, Eric A Bercot, Tomislav Rovis
1Department of Chemistry, Colorado State University, Fort Collins, CO 80523, USA.
Journal of the American Chemical Society
|August 28, 2003
Resumen
Los catalizadores de níquel permiten una nueva reacción de acoplamiento cruzado entre los anhídridos cíclicos y los reactivos organozinc. Este método forma eficientemente nuevos enlaces carbono-carbono con control estereoquímico, ofreciendo una valiosa herramienta sintética.
Área de la Ciencia:
- Química organometálica Química orgánica de los metales.
- Química orgánica sintética y orgánica.
- La catálisis de la catálisis.
Sus antecedentes:
- Los anhídridos cíclicos son precursores versátiles en la síntesis orgánica.
- Desarrollar reacciones eficientes de acoplamiento cruzado para electrófilos sp3 sigue siendo un desafío.
- La catálisis del níquel ofrece una reactividad única para la formación de enlaces C-C.
Objetivo del estudio:
- Desarrollar una nueva reacción de acoplamiento cruzado catalizada por níquel utilizando anhídridos cíclicos.
- Para lograr la formación selectiva de enlaces sp3 ((electrófilo) -sp2 ((nucleófilo).
- Para permitir el control estereoquímico en el proceso de acoplamiento cruzado.
Principales métodos:
- Tratamiento de anidridos cíclicos con un complejo níquel-neocuproína para formar niquelactonas.
- Secuestro in situ de monóxido de carbono (CO) extruido utilizando un complejo níquel-dppb.
- Acoplamiento cruzado de las niquelalactonas con reactivos de arilzinco.
Principales resultados:
- Generación exitosa de alquilcarboxilato-niquel-lactonas a partir de anhídridos cíclicos.
- Demostración del acoplamiento cruzado de la nickelalactona con reactivos de arilzinco.
- Secuestro efectivo de CO, evitando la interferencia con el ciclo catalítico.
- Se logró el acoplamiento cruzado secundario sp3-sp2 con control estereoquímico.
Conclusiones:
- Se ha establecido una nueva ruta sintética catalizada por níquel para el acoplamiento cruzado sp3-sp2.
- El método proporciona una poderosa estrategia para construir moléculas complejas a partir de anhídridos cíclicos.
- El protocolo desarrollado permite un control preciso de la estereoquímica durante la formación de enlaces.
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