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Evidencia para un mecanismo unificador de Ni^I/Ni^III en la catálisis de acoplamiento cruzado mediada por la luz

Lucia Anghileri^1,2,3, Haralds Baunis^1,2, Aleksander R Bena^1,2

¹Institute of Science and Technology Austria (ISTA), Am Campus 1, Klosterneuburg 3400, Austria.

Journal of the American Chemical Society

|April 11, 2025

Resumen

Este estudio introduce un nuevo catalizador de níquel fotoactivo para la formación de enlaces C ((sp2) - C ((sp3)), eliminando la necesidad de catalizadores fotorredóxicos externos. Este avance expande la catálisis del níquel para reacciones de acoplamiento cruzado eficientes.

Área de la Ciencia:

Química organometálica
Fotocatálisis
Química orgánica sintética

Sus antecedentes:

La catálisis del níquel es crucial en la química sintética, a menudo involucrando especies paramagnéticas de níquel.
La modulación del estado de oxidación del níquel a través de la transferencia de un solo electrón es clave para estas reacciones.
Los acoplamientos existentes C(sp2)-heteroátomo y C(sp2)-C(sp3) se basan en ciclos catalíticos específicos y a menudo requieren catalizadores fotorredóxicos exógenos.

Objetivo del estudio:

Desarrollar formaciones de enlaces C ((sp2) -C ((sp3) catalizadas por níquel mediadas por la luz sin catalizadores fotorredóxicos externos.
Ampliar el alcance de los acoplamientos heteroatómicos C ((sp2)) utilizando ligandos fotoactivos.
Identificar un complejo de níquel fotoactivo para reacciones eficientes de acoplamiento cruzado.

Principales métodos:

Utilizó un ligando fotoactivo junto con un catalizador de níquel.
Se han investigado reacciones de acoplamiento cruzado mediadas por la luz entre haluros de arilo y sales de bencil trifluoroborato.
Se han realizado estudios mecanicistas para elucidar el ciclo catalítico.

Principales resultados:

Se ha demostrado la formación exitosa de enlaces C ((sp2) - C ((sp3)) utilizando un ligando fotoactivo, evitando la necesidad de catalizadores fotorredóxicos exógenos.
Identificó un complejo de níquel fotoactivo específico que cataliza los acoplamientos cruzados entre haluros de arilo y sales de bencil trifluoroborato.
Se ha proporcionado evidencia mecanicista de un ciclo catalítico de Ni (I) /Ni (III) que incluye transmitación con compuestos organobóricos.

Conclusiones:

Los ligandos fotoactivos pueden permitir la catálisis del níquel mediada por la luz, simplificando las configuraciones de reacción.
El complejo de níquel desarrollado facilita reacciones eficientes de acoplamiento cruzado C(sp2) -C(sp3).
La comprensión del ciclo Ni (I) /Ni (III) es crucial para el diseño de futuros sistemas catalíticos.

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