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Hierro no clásico estable, pero muy reactivo (II) Complejos de pinzas polihidruro: dimerización y hidroboración
Nikolaus Gorgas, Luis G Alves1, Berthold Stöger
1Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa , Av. Rovisco Pais No. 1, 1049-001 Lisboa, Portugal.
Journal of the American Chemical Society
|June 7, 2017
Resumen
Los nuevos complejos de polihidruro de hierro catalizan la dimerización de alquino a eninas y la formación de boronato de vinilo. Estas reacciones son altamente selectivas y eficientes en condiciones suaves utilizando bajas cargas de catalizador.
Área de la Ciencia:
- Química organometálica
- Catálisis
- Química sintética
Sus antecedentes:
- Los complejos de hierro son alternativas rentables y sostenibles a los catalizadores de metales preciosos.
- Los ligandos de pinza ofrecen una mayor estabilidad y control sobre los centros metálicos.
- Los complejos de polihidruro son intermedios versátiles en las transformaciones catalíticas.
Objetivo del estudio:
- Síntesis y caracterización de nuevos complejos de polihidruro de hierro no clásico con ligandos de pinza PNP.
- Investigar la actividad catalítica de estos complejos en las transformaciones de alquinos.
- Explorar el alcance y la selectividad de los sistemas catalíticos desarrollados.
Principales métodos:
- Síntesis de complejos de polihidruro de hierro con ligandos de pinza PNP tridentados.
- Caracterización mediante técnicas espectroscópicas (por ejemplo, RMN, cristalografía de rayos X).
- Reacciones catalíticas que incluyen la dimerización de alquinos y la borilación en condiciones suaves.
Principales resultados:
- Síntesis exitosa de los complejos [Fe(PNP) ((H) 2 ((η2-H2)).
- Dimerización catalítica eficiente de los acetilenos de arilo a las 1,3-eninas conjugadas con altos rendimientos.
- Formación de boronatos de vinilo a través de la reacción con las alquinas terminales y el pinacolborano.
- Se observó una alta quimio, regio y estereoselectividad (hasta un 99% de selectividad Z) en ambas reacciones.
Conclusiones:
- Los complejos de polihidruro de hierro no clásico son catalizadores efectivos para la funcionalización de alquinos.
- Estos sistemas catalíticos ofrecen una ruta sostenible y eficiente hacia compuestos orgánicos valiosos.
- La metodología desarrollada proporciona un control preciso de la formación del producto, destacando el potencial de la catálisis del hierro.
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