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Borilación fotoinducida libre de metales de los alcanos C (sp3) -H
Chao Shu1, Adam Noble2, Varinder K Aggarwal3
1School of Chemistry, University of Bristol, Bristol, UK.
Nature
|October 29, 2020
Resumen
En este estudio se introduce un nuevo método de borilación de C ((sp3) -H sin metales. Utiliza la transferencia de átomos de hidrógeno inducida por la luz para funcionalizar selectivamente los alcanos no reactivos en reactivos orgánicos valiosos.
Área de la Ciencia:
- Química orgánica
- Catálisis
- Ciencias de los materiales
Sus antecedentes:
- Los ácidos borónicos son vitales en productos farmacéuticos, agroquímicos y materiales.
- La borilación catalítica de C-H permite la funcionalización directa de los enlaces de C-H.
- Los métodos tradicionales utilizan metales preciosos, favoreciendo los enlaces aromáticos C ((sp2) -H sobre los alifáticos C ((sp3) -H.
Objetivo del estudio:
- Desarrollar un método de borilación de C ((sp3) -H sin metales.
- Para lograr la funcionalización selectiva de los alcanos no reactivos.
- Para contrastar las selectividades con los protocolos catalizados por metales.
Principales métodos:
- Utiliza la catálisis de transferencia de átomos de hidrógeno a través de un catalizador de cloruro.
- Utiliza transferencia de electrones inducida por la luz violeta.
- Involucra la escisión del enlace homolítico C ((sp3) -H para formar radicales alquilo, seguido de la berilación.
Principales resultados:
- Obtiene la borilación libre de metales C ((sp3) -H en condiciones suaves.
- Demuestra una selectividad inusual para los enlaces metilo C-H más fuertes sobre los más débiles.
- Identifica un complejo de radicales de cloro y boro responsable de la selectividad estérica.
Conclusiones:
- Esta estrategia de transferencia de átomos de hidrógeno fotoinducida ofrece una nueva ruta a los compuestos de organoboron.
- El enfoque sin metales transforma los alcanos no reactivos en reactivos valiosos.
- La selectividad observada proporciona una alternativa distinta a la borilación catalizada por metales.
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