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Los enlaces borilo-metálicos facilitan la hidrogenación de las olefinas catalizadas por cobalto/níquel

Tzu-Pin Lin¹, Jonas C Peters

¹Division of Chemistry and Chemical Engineering, California Institute of Technology , Pasadena, California 91125, United States.

Journal of the American Chemical Society

|September 3, 2014

Resumen

Nuevos complejos bimetálicos de cobalto y níquel con ligandos de boro únicos permiten una hidrogenación eficiente de las olefinas. Estos catalizadores imitan el rendimiento de los metales nobles en condiciones suaves, mostrando una reactividad reversible de H2 sin precedentes en especies de níquel.

Área de la Ciencia:

Química organometálica Química orgánica de los metales.
La catálisis de la catálisis.
Química Inorgánica La Química Inorgánica es la química inorgánica.

Sus antecedentes:

El desarrollo de catalizadores metálicos de primera fila tardía para las transformaciones reductoras de dos electrones es crucial.
Imitar la eficiencia del catalizador de metales nobles con metales abundantes en la tierra sigue siendo un desafío significativo.
La hidrogenación de olefinas es un proceso industrial clave que requiere sistemas catalíticos eficientes.

Objetivo del estudio:

Para sintetizar nuevos complejos bimetálicos de cobalto y níquel con ligandos bis ((phosphino) borilo.
Para investigar la actividad catalítica de estos complejos en la hidrogenación de olefinas.
Para explorar la reactividad única de los centros metálicos ligados por borilo.

Principales métodos:

Síntesis de complejos bimetálicos de cobalto y níquel.
Estudios de activación de hidrógeno reversible.
Catálisis de hidrogenación de olefinas bajo condiciones suaves (temperatura ambiente, 1 atm H2).
Estudios cinéticos para elucidar los mecanismos de reacción.

Principales resultados:

Se sintetizó un complejo de cobalto bimetálico S=1 estructuralmente inusual, [((Cy) PBP) CoH]2, que mostró actividad de hidrogenación de olefinas.
Un relacionado dimer de Ni, [Ph]PBP) Ni2, exhibió una reactividad reversible sin precedentes con H2, formando [Ph]PBHP) NiH]2.
El monómero ((tBu) PBP) NiH demostró una mayor actividad de hidrogenación en comparación con los análogos que carecen del ligando borilo.

Conclusiones:

Los complejos bimetálicos de cobalto y níquel con ligandos de borilo son catalizadores efectivos de la hidrogenación de las olefinas.
El ligando borilo juega un papel crítico en la reactividad H2 reversible única de los complejos Ni (I).
La fuerte influencia trans del ligando borilo mejora la actividad catalítica en los complejos monoméricos de níquel.

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