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Preparación de complejos alquilo estables de Ni (I) y su oxidación de un electrón a cationes complejos de Ni (II)
Kristina D Kitiachvili1, Daniel J Mindiola, Gregory L Hillhouse
1Searle Chemistry Laboratory, Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, USA.
Journal of the American Chemical Society
|August 26, 2004
Resumen
Nuevos complejos de alquilo de níquel (I) fueron sintetizados y oxidados a cationes de níquel (II). Inesperadamente, estos cationes se sometieron a la desprotonación gamma-CH3, formando productos de metalaciclobutano en lugar de los derivados de imido o fosfinideno anticipados.
Área de la Ciencia:
- Química organometálica Química orgánica de los metales.
- Catálisis de níquel y níquel.
- Coordinación Química de la Coordinación
Sus antecedentes:
- Los complejos de alquilo de tres coordenadas de níquel (I) son valiosos intermedios sintéticos.
- Comprender la reactividad de los alquilos de metales de transición de baja valencia es crucial para la catálisis.
- Estudios previos mostraron alfa-deprotonación en complejos catiónicos relacionados.
Objetivo del estudio:
- Para sintetizar y caracterizar nuevos complejos de alquilo de tres coordenadas de níquel.
- Para investigar la oxidación y la posterior reactividad de estos complejos de níquel.
- Para explorar las vías de desprotonación de los cationes de níquel resultantes.
Principales métodos:
- Síntesis de complejos de alquilo de níquel (I) utilizando reactivos de alquillitio.
- Oxidación de un electrón para formar cationes complejos de níquel (II).
- Caracterización de productos utilizando técnicas espectroscópicas y analíticas.
- Investigación de las reacciones de desprotonación.
Principales resultados:
- Se prepararon con éxito complejos de alquilo de níquel con tres coordenadas: (dtbpe) Ni (CH2CMe3), (dtbpe) Ni (CH2SiMe3) y (dtbpe) Ni (CH2CMe2Ph).
- La oxidación produjo níquel estable (II) cationes complejos.
- La desprotonación se produjo en un grupo gamma-CH3, lo que condujo a la formación de productos de metallaciclobutano.
- La reactividad observada contrasta con la alfa-deprotonación observada en complejos análogos de amido y fosfido.
Conclusiones:
- Los complejos de alquilo de níquel sintetizado exhiben estabilidad térmica.
- La oxidación a cationes de níquel (II) es fácil.
- Se observó una inusual vía de desprotonación gamma-CH3, que produce metaciclobutanos.
- Esta reactividad expande la química conocida de los complejos de níquel de baja valencia.
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