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Descarbonización reductora catalizada por Ni de alquenos no activados: alcance y conocimientos mecánicos

Wei Shu¹, Andrés García-Domínguez¹, M Teresa Quirós²

¹Department of Chemistry , University of Zurich , Winterthurerstrasse 190 , Zurich CH 8057 , Switzerland.

Journal of the American Chemical Society

|August 22, 2019

Resumen

Este estudio introduce una nueva dicarbofuncionalización catalizada por níquel de las olefinas utilizando dos fuentes de carbono electrófilas. El método forma eficientemente enlaces C ((sp3) -C ((sp3) y C ((sp3) -C ((sp2)) a través de un mecanismo radical.

Área de la Ciencia:

Química orgánica
Catálisis
Mecanismos de reacción

Sus antecedentes:

Las olefinas son bloques de construcción versátiles en la síntesis orgánica.
La dicarbofuncionalización directa de las olefinas no activadas sigue siendo un reto.
El desarrollo de métodos selectivos para la formación de enlaces C-C es crucial.

Objetivo del estudio:

Desarrollar un nuevo método para la dicarbofuncionalización de olefinas no activadas.
Para lograr la formación simultánea de enlaces C ((sp3) - C ((sp3)) y C ((sp3) - C ((sp2).
Para aclarar el mecanismo de reacción.

Principales métodos:

Funcionalización reductiva de las olefinas catalizada por el níquel.
Utilizando dos fuentes de carbono electrófilas.
Utilizando el tetraquis (dimetilamino) etileno (TDAE) como un reductor de sacrificio.
Experimentos de control y estudios computacionales.

Principales resultados:

Formación simultánea de un enlace C ((sp3) -C ((sp3)) y un enlace C ((sp3) -C ((sp2)) a través de sistemas π imparciales.
Se logra una selectividad exquisita utilizando un catalizador de Ni y TDAE.
Factibilidad de un mecanismo basado en radicales que incluya ciclos de Ni (I) /Ni (III).
Se ha demostrado la capacidad variable de las especies de Ni (I) para reducir los enlaces C (sp3) -I.
Reducción de un electrón termodinámicamente favorecida de Ni (II) a Ni (I).

Conclusiones:

El método desarrollado proporciona una herramienta poderosa para la dicarbofuncionalización de la olefina.
La reacción procede a través de una vía radical única.
La comprensión de los detalles mecánicos permite el control de la selectividad y la formación de productos.

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