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Hidroarillación selectiva por ramificación: acoplamiento cruzado de iodoareno y olefina

Samantha A Green¹, Jeishla L M Matos¹, Akiko Yagi¹

¹Department of Chemistry, The Scripps Research Institute , 10550 North Torrey Pines Road, La Jolla, California 92037, United States.

Journal of the American Chemical Society

|September 14, 2016

Resumen

Este estudio introduce un nuevo método catalítico que utiliza cobalto y níquel para lograr una hidroarilación de las olefinas de Markovnikov altamente selectiva. Los hallazgos sugieren un mecanismo que involucra la transferencia de átomos de hidrógeno e intermedios radicales, lo que permite una generación radical eficiente centrada en el carbono.

Área de la Ciencia:

Química orgánica
Catálisis
Mecanismos de reacción

Sus antecedentes:

La hidroarilación de olefinas es una reacción crucial en la síntesis orgánica.
El logro de una alta selectividad regional, en particular la selectividad de Markovnikov, sigue siendo un desafío.
El desarrollo de sistemas catalíticos eficientes es esencial para la síntesis química sostenible.

Objetivo del estudio:

Desarrollar un método de hidroarilación de olefinas altamente selectivo (Markovnikov).
Para aclarar el mecanismo catalítico que involucra cobalto y níquel.
Explorar el papel de los radicales intermedios en la vía de reacción.

Principales métodos:

Utilizó un sistema catalítico combinado de cobalto y níquel.
Investigó las vías de reacción a través de experimentos de ciclización radical.
Los intermediarios de reacción analizados mediante experimentos de escisión de anillos.
Se utiliza la transferencia de átomos de hidrógeno (HAT) para generar radicales centrados en el carbono.

Principales resultados:

Se ha logrado una hidroarilación de olefinas altamente selectiva (Markovnikov).
Demostró la acción sinérgica de los ciclos catalíticos de cobalto y níquel.
Se ha proporcionado evidencia de la transferencia de átomos de hidrógeno (HAT) que inicia el proceso catalítico.
Identificó la generación de un radical centrado en el carbono que conduce al compromiso del ciclo del níquel.

Conclusiones:

Un nuevo sistema catalítico que combina cobalto y níquel permite una hidroarilación altamente selectiva de las olefinas de Markovnikov.
La reacción procede a través de un mecanismo que implica la transferencia de átomos de hidrógeno y los pasos subsiguientes catalizados por níquel.
Este trabajo ofrece una nueva estrategia para la funcionalización selectiva C-H de las olefinas.

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