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Un complejo de Ni-Li-Olefin muy reducido para acoplamientos cruzados catalíticos Kumada-Corriu

Lukas Nattmann¹, Sigrid Lutz¹, Pascal Ortsack¹

¹Max-Planck-Institut für Kohlenforschung , Kaiser-Wilhelm-Platz 1 , Mülheim an der Ruhr , 45470 , Germany.

Journal of the American Chemical Society

|October 11, 2018

Resumen

Un nuevo catalizador de níquel con alta densidad de electrones permite reacciones eficientes de acoplamiento cruzado Kumada-Corriu a temperaturas criogénicas. Este avance permite el acoplamiento de grupos funcionales sensibles, ampliando las posibilidades sintéticas.

Área de la Ciencia:

Química organometálica
Catálisis
Química orgánica sintética

Sus antecedentes:

El acoplamiento cruzado Kumada-Corriu es una reacción vital para la formación de enlaces carbono-carbono.
El desarrollo de catalizadores eficientes y versátiles sigue siendo un desafío clave en la síntesis orgánica.
Los catalizadores de níquel ofrecen una alternativa rentable al paladio para las reacciones de acoplamiento cruzado.

Objetivo del estudio:

Investigar la actividad catalítica de un complejo de níquel altamente reducido en el acoplamiento cruzado Kumada-Corriu.
Explorar el potencial de este catalizador para operar bajo condiciones criogénicas.
Para aclarar el mecanismo de catálisis que involucra especies de níquel altamente reducidas.

Principales métodos:

Síntesis y caracterización de un complejo de níquel altamente rico en electrones estabilizado por ligandos olefinos y iones de litio.
Evaluación del rendimiento del precatalizador en reacciones de acoplamiento cruzado Kumada-Corriu a bajas temperaturas.
Elucidación estructural de los productos intermedios clave mediante técnicas espectroscópicas y estudios de reactividad.

Principales resultados:

El precatalizador de níquel demostró una reactividad histórica en el acoplamiento cruzado Kumada-Corriu a temperaturas criogénicas.
La alta densidad de electrones del catalizador, facilitada por los ligandos olefinos y los iones Li, es crucial para su actividad.
La operabilidad a bajas temperaturas preserva grupos funcionales sensibles durante la reacción.
La evidencia sugiere que las especies de níquel altamente reducidas están involucradas en el ciclo catalítico y la formación de enlaces C-C.

Conclusiones:

Un catalizador de níquel altamente reducido permite el acoplamiento cruzado Kumada-Corriu bajo condiciones criogénicas.
Las propiedades electrónicas únicas del catalizador y el funcionamiento a baja temperatura amplían el alcance para sintetizar moléculas complejas.
La comprensión del papel de los intermedios altamente reducidos proporciona información sobre los mecanismos de acoplamiento cruzado catalizados por níquel.

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