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Adición selectiva por ramificación de olefinas no activadas a las iminas y aldehídos
Jeishla L M Matos1, Suhelen Vásquez-Céspedes1, Jieyu Gu1
1Department of Chemistry , The Scripps Research Institute , 10550 North Torrey Pines Road , La Jolla , California 92037 , United States.
Journal of the American Chemical Society
|November 23, 2018
Resumen
Este estudio introduce un nuevo método para el acoplamiento reductivo de las olefinas con las iminas y los aldehídos mediante la catálisis de metales. Este avance amplía el alcance de las reacciones de hidrofuncionalización radical para la síntesis orgánica.
Área de la Ciencia:
- Química orgánica
- Catálisis
- Metodología sintética
Sus antecedentes:
- La hidrofuncionalización radical es una herramienta poderosa para acoplar alquenos con electrófilos.
- Los métodos tradicionales luchan con electrofilos de dos electrones no reactivos como las iminas y los aldehídos.
- La catálisis de transferencia de átomos de hidrógeno de hidrógeno metálico (MHAT) ha demostrado ser prometedora, pero requiere un mayor desarrollo.
Objetivo del estudio:
- Desarrollar nuevos sistemas catalíticos para el acoplamiento reductor de olefinas no activadas con iminas y aldehídos.
- Ampliar el alcance del sustrato y la aplicabilidad de las reacciones de hidrofuncionalización radical.
- Para permitir la síntesis de moléculas orgánicas valiosas a través de la formación eficiente de enlaces C-C.
Principales métodos:
- Se utilizó la catálisis del hierro para el acoplamiento reductor de las olefinas con las iminas a través de radicales libres intermedios.
- Se utiliza una combinación de catalizadores de cobalto y cromo para el acoplamiento selectivo de olefinas con aldehídos.
- Investigó los mecanismos de reacción, incluida la formación de supuestos intermedios de alquilo-cromo.
Principales resultados:
- Se ha logrado un acoplamiento reductivo exitoso de olefinas electrónicamente imparciales con iminas y aldehídos.
- Se ha demostrado la adición catalizada por hierro de olefinas sustituidas por alquilo a las iminas.
- Desarrolló un sistema catalítico Co/Cr para el acoplamiento selectivo de olefinas y aldehídos.
Conclusiones:
- Los métodos presentados proporcionan vías eficientes para el acoplamiento reductivo, ampliando la utilidad de la hidrofuncionalización radical.
- Estos sistemas catalíticos ofrecen nuevas estrategias para construir moléculas orgánicas complejas a partir de precursores simples.
- Los hallazgos allanan el camino para futuros avances en la funcionalización de C-H catalizada por metales y la formación de enlaces C-C.
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