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Alquilación descarboxilada N-heterocíclica catalizada por carbenos de los aldehídos

Takuya Ishii¹, Yuki Kakeno¹, Kazunori Nagao¹

¹Division of Pharmaceutical Sciences, Graduate School of Medical Sciences , Kanazawa University , Kakuma-machi, Kanazawa 920-1192 , Japan.

Journal of the American Chemical Society

|February 21, 2019

Resumen

La catálisis de carbenos N-heterocíclicos permite un nuevo acoplamiento descarboxilativo de aldehídos de arilo y derivados de ácido carboxílico para formar cetonas de alquilo de arilo. Este método sin metales de transición ofrece condiciones suaves para sintetizar moléculas complejas.

Área de la Ciencia:

Química orgánica
Catálisis
Metodología sintética

Sus antecedentes:

Las reacciones de acoplamiento descarboxilativo son cruciales para la formación de enlaces C-C.
El desarrollo de sistemas catalíticos eficientes y suaves sigue siendo un desafío clave en la síntesis orgánica.

Objetivo del estudio:

Desarrollar una nueva reacción de acoplamiento descarboxilativo utilizando catálisis de carbenos heterocíclicos (NHC).
Para lograr la síntesis de cetonas de alquilo de arilo a partir de materiales de partida fácilmente disponibles en condiciones suaves.

Principales métodos:

Se utiliza como catalizador el carbeno N-heterocíclico (NHC).
Se utilizan aldehídos de arilo y ésteres redox activos derivados de ácido alquilo carboxílico terciario o secundario como sustratos.
Realizó la reacción en condiciones libres de metales de transición.

Principales resultados:

Se logró un acoplamiento descarboxilativo sin precedentes de aldehídos de arilo y ésteres redox-activos.
Con éxito sintetizó una gama de cetonas arilo-alquilo.
Demostró la aplicabilidad del método mediante la funcionalización de medicamentos farmacéuticos y productos naturales.
Propuso un mecanismo de reacción que involucra la transferencia de un solo electrón y la recombinación de pares de radicales.

Conclusiones:

La catálisis NHC proporciona una vía efectiva y suave para el acoplamiento descarboxilativo.
El protocolo desarrollado ofrece una herramienta valiosa para la construcción de cetonas arilo-alquilo.
La naturaleza libre de metales de transición de la reacción aumenta su atractivo para aplicaciones sintéticas.

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