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Arilación intramolecular de alcano catalizada por paladio de alto rendimiento: desarrollo de la reacción y estudios

Marc Lafrance¹, Serge I Gorelsky, Keith Fagnou

¹Center for Catalysis Research and Innovation, University of Ottawa, Department of Chemistry, 10 Marie Curie, Ottawa, Ontario, Canada K1N 6N5.

Journal of the American Chemical Society

|November 8, 2007

Resumen

Este estudio introduce una nueva reacción catalizada por el paladio para crear moléculas específicas de dihidrobenzofurano. El método logra altos rendimientos y selectividad mediante la utilización de una vía de reacción única que implica interacciones agósticas.

Área de la Ciencia:

Química orgánica es la química orgánica.
La catálisis de la catálisis.

Sus antecedentes:

Las reacciones catalizadas por el paladio son cruciales en la síntesis orgánica.
Desarrollar métodos selectivos para la funcionalización C-H sigue siendo un desafío.

Objetivo del estudio:

Desarrollar una nueva arylación de alcano catalizada por paladio para la síntesis de sustratos de 2,2-dialquilo-dihidrobenzofurano.
Para dilucidar el mecanismo de reacción y comprender los factores que rigen la selectividad.

Principales métodos:

Reacciones de acoplamiento cruzado catalizadas por paladio utilizando haluros de arilo.
Estudios mecánicos que incluyen mediciones del efecto del isótopo cinético.
Modelado computacional para investigar las estructuras e interacciones del estado de transición.

Principales resultados:

Excelentes rendimientos y alta selectividad del sitio para la formación de 2,2-dialquilo-dihidrobenzofurano.
Identificación de una vía concertada de paladación-desprotonación en la esfera interna.
Evidencia de interacciones agósticas de tres centros que estabilizan el estado de transición.

Conclusiones:

La reacción descrita catalizada por el paladio ofrece una ruta eficiente a valiosos andamios de dihidrobenzofuranos.
Los conocimientos mecanicistas, en particular el papel de las interacciones agósticas, proporcionan una base para el diseño de nuevos sistemas catalíticos.
Los hallazgos contribuyen a una comprensión más amplia de las estrategias de activación y funcionalización de C-H.

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