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Pruebas experimentales y computacionales para una vía de metátesis de enlaces sigma asistida por boro para la

Charles Edwin Webster¹, Yubo Fan, Michael B Hall

¹Department of Chemistry, Texas A&M University, College Station, TX 77843-3255, USA.

Journal of the American Chemical Society

|January 23, 2003

Resumen

La fotoyección de los ligandos de CO de los complejos metálicos genera intermedios que activan los enlaces C-H. El boro y el boro.

Área de la Ciencia:

Química organometálica Química orgánica de los metales.
La catálisis es la catálisis.
La activación de la C-H.

Sus antecedentes:

La fotoyección de los ligandos de CO de los complejos CpM ((CO) n+1BR2) genera intermedios de 16 electrones.
Estos intermediarios presentan ligandos cíclicos de dioxaborilo y son capaces de activar enlaces C-H.

Objetivo del estudio:

Investigar el mecanismo de activación del enlace C-H iniciado por los complejos de metales de transición de dioxaborilo.
Para aclarar el papel del orbital p desocupado del ligando de dioxaborilo en el proceso de activación de C-H.

Principales métodos:

Estudios experimentales que involucran fotoyección y funcionalización C-H.
Cálculos teóricos para sondear los mecanismos de reacción y los efectos electrónicos.

Principales resultados:

Se ha demostrado una activación eficiente y regioselectiva del enlace C-H por los intermediarios de 16 electrones de dioxaborilo.
Se demostró que el orbital p desocupado del átomo de boro es crucial para la activación C-H.
Identificó el mecanismo como metatesis de enlace sigma mediada por metales asistida por boro.

Conclusiones:

El orbital p desocupado del boro estabiliza los estados de transición y los intermedios al aceptar la densidad de electrones del metal.
Este mecanismo único facilita la transferencia de hidrógeno al boro y la subsiguiente funcionalización de alcano.
La química observada es distinta de los complejos CpM(CO) n previamente reportados con ligandos alquilo o arilo.

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