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La oxidación de Ni (II) a Ni (IV) con electrófilos de arilo permite el acoplamiento Ni-mediado de arilo-CF3

James R Bour¹, Nicole M Camasso¹, Melanie S Sanford¹

¹University of Michigan, Department of Chemistry, 930 North University Avenue, Ann Arbor, Michigan 48109, United States.

Journal of the American Chemical Society

|June 17, 2015

Resumen

Este estudio detalla la creación y las reacciones de los complejos de níquel (IV), mostrando que pueden formarse fácilmente y someterse a pasos clave de formación de enlaces. Estos hallazgos sugieren que el níquel (IV) puede ser importante en las reacciones de acoplamiento catalítico.

Área de la Ciencia:

Química organometálica Química orgánica de los metales.
La catálisis por catálisis.
Química del flúor Química del flúor

Sus antecedentes:

Los complejos de níquel son cruciales en la catálisis.
Comprender los estados de oxidación más altos del níquel es clave para desarrollar nuevas reacciones.
Los ligandos tris ((pyrazolyl) borate y bipyridine son comunes en la estabilización de los complejos metálicos.

Objetivo del estudio:

Para sintetizar y caracterizar nuevos complejos de níquel (IV).
Investigar la reactividad de estas especies de níquel (IV), particularmente en la formación de enlaces.
Explorar el papel potencial de los intermediarios de níquel (IV) en los ciclos catalíticos.

Principales métodos:

Oxidación de los precursores del Ni (II) utilizando reactivos específicos de triflato.
Síntesis de complejos de níquel (IV) apoyados por los ligandos trispirazolilborato y di-tert-butilobipiridina.
Caracterización de los complejos Ni (IV) resultantes y análisis de su reactividad.

Principales resultados:

Se sintetizaron con éxito complejos aislables de Ni(IV) con ligandos de arilo y trifluorometil (CF3) en condiciones suaves.
Los intermediarios Ni(IV) forman eficientemente enlaces arilo-CF3 a través de la eliminación reductora.
La síntesis se logró utilizando varios oxidantes, incluidos los reactivos de diaryliodonium y aryldiazonium.

Conclusiones:

Los intermediarios de níquel (IV) pueden ser accedidos y manipulados bajo condiciones prácticas.
La formación de enlaces aril-CF3 demostrada es una vía de reactividad significativa para estos complejos.
Estos hallazgos ponen de relieve la utilidad potencial de las especies de Ni ((IV) en reacciones de acoplamiento cruzado catalizadas por níquel.

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