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Complejos de dialquilo de bis ((fosfina) cobalto para la hidrogenación catalítica dirigida de alquenos

Max R Friedfeld¹, Grant W Margulieux, Brian A Schaefer

¹Department of Chemistry, Princeton University , Princeton, New Jersey 08544, United States.

Journal of the American Chemical Society

|August 29, 2014

Resumen

Los complejos de cobalto ((II) de bajo espín catalizan la hidrogenación del alqueno. La activación del grupo hidroxilo permite la hidrogenación de alquenos obstaculizados y la síntesis dirigida de isómeros cíclicos de alcano.

Área de la Ciencia:

Química organometálica Química orgánica de los metales.
La catálisis por catálisis.
Síntesis orgánica La síntesis orgánica.

Sus antecedentes:

Los complejos de cobalto se exploran cada vez más como catalizadores en la síntesis orgánica.
La hidrogenación de alquenos es una transformación fundamental en la química orgánica.

Objetivo del estudio:

Para investigar la actividad catalítica de cobalto planar, de bajo espín (II) complejos dialquilo para la hidrogenación de alquenos.
Desarrollar un método para la hidrogenación de alquenos estéricamente obstaculizados mediante catálisis de cobalto.
Para lograr la hidrogenación dirigida para la síntesis de isómeros de alcano cíclicos específicos.

Principales métodos:

Síntesis de complejos dialquil planos de cobalto de bajo espín (II) con ligandos de fosfina bidentada.
Hidrogenación catalítica de varios alquenos, incluidos sustratos geminales, 1,2-disubstituidos y trisubstituidos.
Utilizando la activación del grupo hidroxilo para facilitar la hidrogenación de alquenos internos y endocíclicos obstaculizados.

Principales resultados:

Los complejos de cobalto hidrogenan eficientemente alquenos geminales y 1,2-disubstituidos.
La activación del grupo hidroxilo permitió la hidrogenación de alquenos trisubstituidos internos y endocíclicos desafiantes.
La hidrogenación dirigida utilizando este método produjo isómeros contrastericos de alcanos cíclicos.

Conclusiones:

Los complejos planos de cobalto de baja espina (II) son catalizadores efectivos para una serie de reacciones de hidrogenación de alquenos.
La activación del grupo hidroxilo representa una poderosa estrategia para superar el obstáculo estérico en la hidrogenación catalítica.
Este enfoque ofrece una nueva ruta para la síntesis estereoselectiva de alcanos cíclicos.

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