Efecto dramático de los ácidos de Lewis en la hidroboración catalizada por el rodio de las olefinas
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Updated: Jun 18, 2026
07:49
Characterizing Lewis Pairs Using Titration Coupled with In Situ Infrared Spectroscopy
Published on: February 20, 2020
Christopher J Lata1, Cathleen M Crudden
1Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario K7L 3N6, Canada.
Journal of the American Chemical Society
|December 9, 2009
Resumen
La adición de ácidos de Lewis como el trispentafluoroborón mejora significativamente las reacciones de hidroboración catalizadas por Rh. Este cocatalizador acelera las reacciones con olefinas alifáticas y aromáticas, mejorando la eficiencia y la selectividad.
Área de la Ciencia:
- Química organometálica Química orgánica de los metales.
- La catálisis de la catálisis.
- Síntesis orgánica La síntesis orgánica.
Sus antecedentes:
- La hidroboración catalizada por el rodio de las olefinas es una transformación sintética crucial.
- Los disolventes no coordinados y las limitaciones del alcance del sustrato han obstaculizado previamente las reacciones con ciertas olefinas.
Objetivo del estudio:
- Para investigar el efecto de los cocatalizadores de ácido de Lewis en la hidroboración catalizada por Rh.
- Para mejorar la eficiencia y la selectividad de la hidroboración de olefinas utilizando borano pinacol.
Principales métodos:
- Utilizó catalizadores de rodio junto con ácidos de Lewis, específicamente tris (pentafluorofenil) borano (B (C6F5) 3).
- Examinó la hidroboración de las olefinas alifáticas y aromáticas con pinacol borano (HBPin).
- Se llevaron a cabo estudios mecanicistas preliminares para aclarar el papel del ácido de Lewis.
Principales resultados:
- El trispentafluoroborono (B(C6F5)3) acelera dramáticamente la hidroboración catalizada por Rh de las olefinas con el borano pinacol (HBPin).
- Las olefinas alifáticas, no reactivas en disolventes no coordinadores, reaccionaron rápidamente en presencia de B (C6F5) 3.3.
- La hidroboración de olefinas aromáticas se hizo más rápida y más selectiva con la adición de B ((C6F5) 3.3.
Conclusiones:
- El Trispentafluoroborón actúa como un cocatalizador crucial, esencial durante toda la reacción, no sólo en la iniciación.
- El ácido de Lewis, junto con el THF, está implicado en la escisión heterolítica del enlace B-H en HBPin.
- Este descubrimiento ofrece un método más eficiente y selectivo para la hidroboración de olefinas.
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