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Catálisis sinérgica de LMCT y Ni para el acoplamiento cruzado metilativo utilizando tert-butanol: modulación de las

Lingfei Duan¹, Yunzhi Lin¹, Qing An¹

¹State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Shanghai 200032, China.

Journal of the American Chemical Society

|April 19, 2025

Resumen

Este estudio introduce un nuevo método fotocatalítico que utiliza la transferencia de carga de ligando a metal (LMCT) y la catálisis del níquel para generar radicales metílicos a partir del tert-butanol para la formación eficiente de enlaces C-CH3. El enfoque ofrece una alternativa más ecológica para las reacciones de metilación.

Área de la Ciencia:

Química orgánica
Fotocatálisis
La Química Radical

Sus antecedentes:

La transferencia de carga de ligando a metal (LMCT) es efectiva para generar radicales heteroatómicos.
La modulación de las vías de radicales de caparazón abierto utilizando LMCT está poco explorada.
El desarrollo de reactivos de metilación eficientes y benignos es crucial.

Objetivo del estudio:

Para desarrollar una reacción de acoplamiento metilativo fotocatalítico.
Para utilizar el tert-butanol como un reactivo de metilación a través del LMCT y la catálisis del Ni.
Explorar la interacción sinérgica entre el LMCT y la catálisis de Ni en la generación de radicales.

Principales métodos:

Utilizando una reacción mediada por Ce (IV) con un ligando de 2,6-difluorometilbenzoato.
Utilizando el tert-butanol como el precursor de la metilación.
Investigar el mecanismo de reacción a través de estudios mecanicistas.

Principales resultados:

Formación eficiente de enlaces C-CH3 a través de la captura del radical metilo por el catalizador de Ni.
Metilación exitosa de los carbonos sp3 y sp2 en condiciones suaves.
Se ha demostrado una amplia tolerancia del grupo funcional y la aplicabilidad de la funcionalización en etapa tardía.
Se obtiene el acoplamiento trideuterometilativo utilizando tert-butanol-d10.

Conclusiones:

La estrategia desarrollada ofrece una alternativa sostenible a los precursores radicales tradicionales como los peróxidos.
El ligando benzoato es clave para la excitación de LMCT y la generación de radicales metilo.
El mecanismo de reacción implica la homólisis concertada de enlaces Ce-OR y beta-C-C, favoreciendo las vías radicales deseadas.

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