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Catalización de las ciclizaciones radicales de los yoduros de alquilo bajo H2: Evidencia de la transferencia de
Jonathan L Kuo1, Chris Lorenc1, Janine M Abuyuan2
1Department of Chemistry , Columbia University , 3000 Broadway , New York , New York 10027 , United States.
Journal of the American Chemical Society
|March 16, 2018
Resumen
Los investigadores desarrollaron un método libre de estaño para las ciclizaciones radicales utilizando un sistema catalítico. Este enfoque ofrece una alternativa ecológica a los reactivos tradicionales a base de estaño para la síntesis orgánica.
Área de la Ciencia:
- Química orgánica
- Química ecológica
- Catálisis
Sus antecedentes:
- Las ciclizaciones radicales tradicionales a menudo se basan en el hidruro de tributiltina (Bu3SnH), lo que plantea preocupaciones ambientales.
- Hay una necesidad de equivalentes sintéticos sostenibles al átomo de hidrógeno en las reacciones radicales.
Objetivo del estudio:
- Desarrollar alternativas ecológicamente benignas y sin estaño para las ciclizaciones radicales.
- Para explorar el potencial catalítico de [CpV ((CO) 3H) - como fuente de átomo de hidrógeno.
Principales métodos:
- Se utilizó un sistema catalítico que incluía [CpV ((CO) 3H]−, H2 y una base.
- Se han realizado ciclizaciones de radicales catalíticos libres de estaño en sustratos de yoduro de alquilo.
- Investigó el mecanismo, sugiriendo la transferencia inicial de electrones para la generación de radicales.
Principales resultados:
- Se han logrado con éxito ciclizaciones de radicales catalíticos libres de estaño de alquilo yoduros.
- Condiciones de reacción atómicamente eficientes y suaves con una amplia tolerancia de grupo funcional.
- Se informó de la primera ciclización de radicales 5-exo que involucra el ataque a un cloruro de vinilo.
Conclusiones:
- El sistema [CpV(CO) 3H] - sirve como una alternativa eficaz y catalítica sin estaño al Bu3SnH.
- Este método proporciona un enfoque más ecológico y sostenible para las ciclizaciones radicales.
- Los hallazgos abren nuevas vías para emplear cloruros de vinilo en reacciones de ciclización radical.
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