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Habilitando la hidrogenación catalítica de cetonas por pares de Lewis frustrados
Tayseer Mahdi1, Douglas W Stephan
1Department of Chemistry, University of Toronto , 80 St. George Street, Toronto, Ontario M5S 3H6, Canada.
Journal of the American Chemical Society
|October 22, 2014
Resumen
Este estudio demuestra la hidrogenación catalítica de cetonas utilizando gas hidrógeno y un ácido de Lewis a base de boro. El frustrado sistema de pares de Lewis activa efectivamente el hidrógeno para la reducción de cetonas en varios ejemplos.
Área de la Ciencia:
- Química orgánica es la química orgánica.
- La catálisis de la catálisis.
- Química del organoborón Química del organoborón
Sus antecedentes:
- La hidrogenación de cetonas es una transformación fundamental en la síntesis orgánica.
- La activación del hidrógeno molecular (H2) para las reducciones catalíticas a menudo requiere metales de transición.
- El desarrollo de sistemas catalíticos libres de metales para la hidrogenación es altamente deseable.
Objetivo del estudio:
- Desarrollar un nuevo sistema catalítico libre de metales para la hidrogenación de cetonas.
- Para explorar la utilidad de los pares de Lewis frustrados en la activación de H2 para las transformaciones orgánicas.
- Para demostrar el alcance y la eficiencia del sistema catalítico propuesto.
Principales métodos:
- Hidrogenación catalítica de varias alquil y aril cetonas.
- Utilizando 5 mol% de tris (pentafluorofenil) borano (B (C6F5) 3) como catalizador del ácido de Lewis.
- El empleo de disolventes etéreos para facilitar la activación frustrada del par de Lewis del H2.
Principales resultados:
- Se logró una hidrogenación catalítica exitosa de 18 diferentes sustratos cetónicos.
- El catalizador de boro, junto con el disolvente etéreo, formó un par de Lewis frustrado (FLP).
- El FLP activó efectivamente el H2, permitiendo la reducción de cetonas a alcoholes.
Conclusiones:
- El tris ((pentafluorofenil) borano en disolventes etéreos constituye un par de Lewis frustrado eficaz para la activación de H2.
- Este sistema proporciona una ruta catalítica libre de metales para la hidrogenación de las cetonas alquilo y arilo.
- La metodología ofrece una alternativa prometedora para la reducción de cetonas en la síntesis orgánica.
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