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Published on: May 21, 2019
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Acoplamiento de tipo Chan-Evans-Lam de transición inducido por foto: modo de fotoexcitación dual con efecto aniónico
Zijun Zhou1,2, Jeonguk Kweon1,2, Hoimin Jung1,2
1Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon 34141, South Korea.
Journal of the American Chemical Society
|May 13, 2022
Resumen
Este estudio introduce un nuevo método sin metales para crear N-arilamidas utilizando la luz. El proceso acopla eficientemente las fuentes de arilo con las dioxazolonas, facilitado por los aniones cloruro en condiciones suaves.
Área de la Ciencia:
- Química orgánica
- La fotoquímica
- Metodología sintética
Sus antecedentes:
- Las reacciones de acoplamiento catalizadas por metales de transición son vitales en la síntesis orgánica.
- El desarrollo de alternativas libres de metales ofrece ventajas en costos, toxicidad y purificación.
- Los métodos eficientes para la formación de enlaces C (arilo) -N son cruciales para la síntesis de amidas.
Objetivo del estudio:
- Desarrollar un nuevo método fotoinducido y libre de metales de transición para la formación de enlaces C (arilo) -N.
- Para utilizar los ácidos arilborónicos o las tri (aril) boroxinas y las 1,4,2-dioxazol-5-onas como socios de acoplamiento.
- Para establecer una vía sintética versátil y suave para las N-arilamidas.
Principales métodos:
- Reacción fotoinducida mediante el uso de ácidos arilborónicos/tri-arilboróxinas y 1,4,2-dioxazol-5-ones.
- La inclusión de aniones cloruro (generados in situ o añadidos) como un componente cooperativo crucial.
- Investigaciones mecanicistas que incluyen fotoexcitaciones y transferencia de electrones individuales (SET).
Principales resultados:
- Síntesis exitosa de una amplia gama de N-arilamidas bajo condiciones fotográficas suaves.
- Demostración de la utilidad del método mediante reacciones a gran escala y síntesis de arylamidas etiquetadas con 15N.
- Identificación de dos fotoexcitaciones distintas que facilitan la activación de la dioxazolona y la migración al arilo.
Conclusiones:
- Se ha desarrollado una estrategia novedosa, eficiente y libre de metales de transición para la formación de enlaces C (arilo) -N fotoinducidos.
- El método ofrece un acceso conveniente a N-arilamidas sintéticamente versátiles.
- El estudio destaca el papel cooperativo de los aniones cloruro y propone una vía mecanicista que involucra la migración de SET y arilo.
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