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Deshidrogenación selectiva del sitio sin receptor de alifáticos habilitada por la catálisis dual
Min-Jie Zhou1,2, Lei Zhang3, Guixia Liu2
1Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, China.
Journal of the American Chemical Society
|September 30, 2021
Resumen
Este estudio introduce un método novedoso y rentable para la deshidrogenación catalítica de alifáticos (CDA) utilizando luz visible y catalizadores de bajo costo. El proceso permite la síntesis de olefinas funcionalizadas en condiciones suaves sin requerir aceptores de hidrógeno.
Área de la Ciencia:
- Química orgánica
- Catálisis
- La fotoquímica
Sus antecedentes:
- La deshidrogenación catalítica de alifáticos (CDA) está poco explorada en la síntesis orgánica.
- Los métodos CDA existentes a menudo se basan en metales preciosos, oxidantes de sacrificio y condiciones duras, lo que limita su alcance.
- Se necesitan métodos eficientes y selectivos para la síntesis funcional de olefinas.
Objetivo del estudio:
- Desarrollar un sistema de doble catalizador impulsado por luz visible para CDA a temperatura ambiente sin aceptor (Al-CDA).
- Para permitir la deshidrogenación directa de materias primas químicas fácilmente disponibles a las olefinas de diversas funciones.
- Demostrar la aplicabilidad del método a sustratos difíciles como los tioéteres y las amidas.
Principales métodos:
- Se utilizó un sistema de catalizador dual compuesto por un catalizador organofotoredox (2-cloroantraquinona) y un catalizador de metales básicos (cobaloxima).
- Se utiliza la radiación de luz visible para iniciar la reacción.
- Aspectos mecanicistas investigados, incluidas las vías de transferencia de átomos de hidrógeno (HAT).
Principales resultados:
- Alcanzado a temperatura ambiente, sin aceptor-CDA (Al-CDA) utilizando catalizadores de bajo costo y luz visible.
- Demostró por primera vez la desaturación libre de oxidantes de los tioéteres a los sulfuros de alqueno y las amidas a las enamidas.
- Mostró una excepcional selectividad del sitio y tolerancia del grupo funcional a través de la deshidrogenación en etapa tardía de 14 moléculas biológicamente relevantes e ingredientes farmacéuticos.
Conclusiones:
- El sistema de doble catalizador desarrollado ofrece un enfoque simple y eficiente para sintetizar olefinas funcionalizadas.
- Este método supera las limitaciones de las técnicas tradicionales de CDA, expandiendo su utilidad sintética.
- Los conocimientos mecanicistas proporcionan una base para el desarrollo de estrategias de deshidrogenación selectiva.
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