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Enantioselectivo catalítico para la fluoración de cetonas con CsF

Baocheng Wang¹, Shuaixin Fan¹, Chaoshen Zhang¹

¹Department of Chemistry and the Hong Kong Branch of Chinese National Engineering Research Centre for Tissue Restoration & Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, 999077, Hong Kong SAR (China).

Journal of the American Chemical Society

|March 13, 2025

Resumen

Este estudio introduce un nuevo método catalítico para la alfa-fluoración nucleofílica enantioselectiva de las cetonas. El nuevo enfoque permite un eficiente control enantio en la formación de enlaces C-F, ofreciendo una estrategia complementaria a los métodos existentes.

Área de la Ciencia:

Química orgánica
Catálisis asimétrica
Química de la fluoración

Sus antecedentes:

La síntesis enantioselectiva de compuestos orgánicos fluorados es crucial para los productos farmacéuticos y los materiales.
Los métodos existentes para la alfa-fluoración de cetonas a menudo tienen limitaciones en el alcance y el estereocontrol.
Es necesario desarrollar nuevos sistemas catalíticos para hacer frente a estos desafíos.

Objetivo del estudio:

Desarrollar una alfa-fluoración nucleofílica enantioselectiva y catalítica de cetonas simples.
Diseñar un nuevo donante de enlaces de hidrógeno (HBD) para la formación eficiente de enlaces C-F.
Establecer un protocolo suave y general para la síntesis de cetonas quirales alfa-fluoro.

Principales métodos:

Diseño y síntesis de un nuevo catalizador donante de enlace de hidrógeno.
Fluoración nucleofílica enantioselectiva utilizando el fluoruro de cesio (CsF) como fuente de fluoruro.
Optimización de las condiciones de reacción, incluida la carga de disolvente, temperatura y catalizador.
Aplicación del protocolo a los precursores racémicos de alfa-ceto sulfonio.

Principales resultados:

El catalizador de HBD desarrollado supera efectivamente las vías de desactivación del catalizador.
Se logró una alta enantioselectividad en la formación de enlaces C-F.
Se estableció un protocolo general y suave para las cetonas alfa-fluoro acíclicas con un centro estereogénico terciario.
El método es complementario de las técnicas de fluoración electrófila existentes.

Conclusiones:

Se ha desarrollado con éxito una nueva enantioselectiva catalítica nucleofílica de alfa-fluoración de cetonas.
El nuevo catalizador de HBD permite un enantiocontrol eficiente y un amplio alcance del sustrato.
Los estudios mecánicos sugieren una transferencia de fase y un mecanismo de resolución cinética dinámica que involucra la unión de aniones habilitada por HBD.

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