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Hidrogenación directa de amidas a alcoholes y aminas bajo condiciones suaves
Ekambaram Balaraman1, Boopathy Gnanaprakasam, Linda J W Shimon
1Department of Organic Chemistry, Weizmann Institute of Science, Rehovot, 76100, Israel.
Journal of the American Chemical Society
|November 6, 2010
Resumen
Un nuevo método catalítico convierte directamente las amidas en alcoholes y aminas a través de la escisión de enlaces C-N. Esta hidrogenación selectiva utiliza un complejo de pinzas de rutenio en condiciones suaves, ofreciendo una transformación eficiente y verde.
Área de la Ciencia:
- La catálisis es la catálisis.
- Química orgánica es la química orgánica.
- Química verde es la química verde.
Sus antecedentes:
- Las transformaciones del grupo funcional de amida son cruciales en la síntesis orgánica.
- Los métodos existentes para la reducción de amidas a menudo requieren condiciones duras o reactivos estequiométricos.
- La escisión selectiva del enlace C-N en las amidas sigue siendo un reto sintético.
Objetivo del estudio:
- Desarrollar un nuevo sistema catalítico para la hidrogenación directa de amidas.
- Para lograr la escisión selectiva del enlace C-N, produciendo alcoholes y aminas.
- Explorar el mecanismo de esta transformación y su aplicabilidad.
Principales métodos:
- Utilizó un complejo de pinzas PNN Ru (II) de base bipiridil como catalizador homogéneo.
- Reacciones de hidrogenación realizadas bajo presión suave y condiciones neutras.
- Investigó el mecanismo de reacción que involucra la cooperación metal-ligando y la aromatización-desaromatización del núcleo de la pinza.
Principales resultados:
- Se logra la hidrogenación selectiva directa de amidas a alcoholes y aminas con escisión de enlaces C-N.
- Se observó un mínimo de productos de escisión de C-O, a excepción de las pequeñas cantidades en anílidos.
- Demostró buenos a excelentes rendimientos para una gama de sustratos de amida.
- El proceso catalítico opera bajo condiciones ambientalmente benignas.
Conclusiones:
- Se ha establecido un nuevo y eficiente sistema catalítico para la hidrogenación de amida.
- El método desarrollado ofrece una vía verde y directa para sintetizar alcoholes y aminas a partir de amidas.
- Las ideas mecanicistas destacan el papel de la cooperación metal-ligando en el ciclo catalítico.
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