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Hidroariación catalizada por cobalto de alquinas a través de la activación del enlace C-H asistida por quelación

Ke Gao¹, Pin-Sheng Lee, Takeshi Fujita

¹Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological Univeristy, 21 Nanyang Link, Singapore 637371.

Journal of the American Chemical Society

|August 18, 2010

Resumen

Los catalizadores de cobalto permiten la adición de arilpiridinas e iminas a las alquinas internas. Esta reacción muestra una alta selectividad y se produce a través de un nuevo mecanismo de activación C-H.

Área de la Ciencia:

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

Sus antecedentes:

Las reacciones de adición a alquinas internas no activadas siguen siendo un reto.
El desarrollo de sistemas catalíticos selectivos es crucial para la síntesis orgánica.

Objetivo del estudio:

Desarrollar un nuevo sistema catalítico para la adición de arilpiridinas e iminas a las alquinas internas.
Para dilucidar el mecanismo de reacción.

Principales métodos:

Sistemas catalíticos ternales que incluyen sales de cobalto, ligandos de fosfina y reactivos de Grignard.
Experimentos de etiquetado de deuterio para sondear los intermediarios de reacción.

Principales resultados:

Se obtienen elevadas regionalidades y estereoselectividades en las reacciones de adición.
Evidencia de la activación de C-H asistida por quelación y la inserción en el enlace Co-H.

Conclusiones:

El sistema catalítico ternario basado en cobalto desarrollado es efectivo para la funcionalización de alquinos.
El mecanismo propuesto implica la activación clave de C-H y las etapas de inserción migratoria.

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