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La orto-borilación ir catalizada de fenoles dirigida por las interacciones electrostáticas de sustrato-ligando: una

Buddhadeb Chattopadhyay^1,2, Jonathan E Dannatt¹, Ivonne L Andujar-De Sanctis³

¹Department of Chemistry, Michigan State University , 578 South Shaw Lane, East Lansing, Michigan 48824-1322 United States.

Journal of the American Chemical Society

|April 29, 2017

Resumen

Los investigadores desarrollaron una nueva estrategia para borilaciones C-H catalizadas por Ir de fenoles, logrando más del 99% de orto selectividad utilizando un catalizador específicamente diseñado y un ligando de etilenoglicol (Beg). Este método ofrece un control preciso de las reacciones químicas.

Área de la Ciencia:

Química organometálica
Catálisis
Síntesis orgánica

Sus antecedentes:

El control de la regioselectividad en la funcionalización C-H es crucial para una síntesis eficiente.
La borilación C-H catalizada por iridio (CHB) ofrece una vía poderosa para introducir grupos funcionales de boro.
El logro de una alta orto selectividad en el CHB de fenoles sigue siendo un desafío.

Objetivo del estudio:

Desarrollar una estrategia para mejorar la orto selectividad en la borilación C-H ir catalizada de fenoles.
Aclarar el papel de las interacciones electrostáticas en la dirección de la regioselectividad.
Diseñar un catalizador mejorado para CHB orto-selectivo superior.

Principales métodos:

Se ha investigado la selectividad utilizando varios sustratos de arilborona pinacolada (Bpin).
Empleó estudios experimentales y modelos computacionales para probar hipótesis.
Diseñó y sintetizó un catalizador de segunda generación con un ligando de etilenoglicol (Beg).

Principales resultados:

Se hipotetizó y confirmó una interacción electrostática entre el grupo Bpin y el ligando de la bipiridina que favorece la orto selectividad.
Los estudios computacionales predijeron una mejor selectividad orto con un ligando Beg.
La validación experimental demostró una selectividad orto > 99% utilizando B2eg2, con conversiones que mejoran la trietilamina.

Conclusiones:

Las interacciones electrostáticas ligando-sustrato proporcionan un elemento de control único para la funcionalización selectiva C-H.
La estrategia y el catalizador desarrollados avanzan significativamente en la boroilación C-H orto-selectiva de fenoles.
Este trabajo abre nuevas vías para el diseño de catalizadores con regioselectividad predecible.

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