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La α-oxidación fenólica enantioselectiva utilizando H2O2 a través de un mecanismo de desaromatización doble inusual
Michael F McLaughlin1, Elisabetta Massolo1, Shubin Liu2
1Department of Chemistry , University of North Carolina at Chapel Hill , Chapel Hill , North Carolina 27599-3290 , United States.
Journal of the American Chemical Society
|January 31, 2019
Resumen
Este estudio introduce un nuevo método para la desaromatización oxidativa de fenoles utilizando peróxido de hidrógeno, generando moléculas complejas a partir de compuestos aromáticos simples. Este enfoque evita los metales pesados y ofrece la primera síntesis asimétrica de valiosos compuestos espirocíclicos.
Área de la Ciencia:
- Química orgánica
- Química sintética
Sus antecedentes:
- Los compuestos aromáticos son materiales de partida rentables para la síntesis de moléculas complejas.
- La desaromatización oxidativa a menudo requiere yodo hipervalente o metales pesados, lo que plantea preocupaciones ambientales y de costos.
Objetivo del estudio:
- Desarrollar un método de desaromatización oxidativa más suave para los 2- ((hydroxymethyl) phenols.
- Para lograr la primera síntesis asimétrica de 1-oxaspiro [2.5] octa-5,7-dien-4-ones.
- Explorar un nuevo mecanismo de reacción distinto de las vías de desaromatización de fenol existentes.
Principales métodos:
- Desaromatización oxidativa de los 2- ((hidroximetil) fenoles utilizando sus derivados ((dicloroacetato).
- El uso de peróxido de hidrógeno como un oxidante suave.
- Utilizando un catalizador de transferencia de fase quiral recientemente desarrollado para la síntesis asimétrica.
Principales resultados:
- Desaromatización oxidativa exitosa de los fenoles a través de un intermediario metido de quinona transitorio.
- Elucidación de un nuevo mecanismo de reacción distinto de los procesos hipervalentes mediados por yodo.
- Demostración de la primera síntesis asimétrica de las 1-oxaspiro[2.5]octa-5,7-dieno-4-ones.
- Confirmación de la utilidad sintética de los productos en futuras transformaciones.
Conclusiones:
- Este trabajo presenta una alternativa sostenible y eficiente a los métodos tradicionales de desaromatización oxidativa.
- La síntesis asimétrica desarrollada proporciona acceso a valiosos andamios espirocíclicos quirales.
- Los hallazgos amplían el alcance de la química de desaromatización del fenol y ofrecen nuevas estrategias sintéticas.
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