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La isomerización de olefinas y la catálisis de hidrosilación por sales de organofluorofosfonio ácido de Lewis
Manuel Pérez1, Lindsay J Hounjet, Christopher B Caputo
1Department of Chemistry, University of Toronto , 80 St. George Street, Toronto, Ontario M5S 3H6, Canada.
Journal of the American Chemical Society
|November 22, 2013
Resumen
Las nuevas sales de organofluorofosfonio actúan como potentes ácidos de Lewis, catalizando eficientemente las reacciones de isomerización, polimerización e hidrosilación de las olefinas. Estos hallazgos abren caminos para nuevas aplicaciones catalíticas en la síntesis orgánica.
Área de la Ciencia:
- Química organometálica Química orgánica de los metales.
- La catálisis es la catálisis.
- Química del flúor Química del flúor
Sus antecedentes:
- Las sales de organofluorofosfonio se exploran por sus propiedades electrónicas únicas.
- La acidez de Lewis en las sales de fosfonio a menudo está vinculada a interacciones orbitales específicas.
Objetivo del estudio:
- Para sintetizar y caracterizar nuevas sales de organofluorofosfonos.
- Para investigar la acidez de Lewis y la actividad catalítica de estas sales.
- Para dilucidar los mecanismos de reacción involucrados en sus aplicaciones catalíticas.
Principales métodos:
- Síntesis de sales de organofluorofosfonio con diferentes sustitutos de fenilo y pentafluorofenilo.
- Pruebas catalíticas en la isomerización de olefinas, la polimerización catiónica y la dimerización de Friedel-Crafts.
- Hidrosilación de olefinas y alquinas mediante el uso de hidrosilanos.
- Estudios experimentales y computacionales para comprender los mecanismos de reacción.
Principales resultados:
- Las sales sintetizadas exhiben una significativa acidez de Lewis debido a un orbital σ* bajo en el fósforo.
- Se observó una catálisis eficiente para la isomerización de 1-hexeno a 2-hexeno.
- Se catalizó con éxito la polimerización catiónica del isobutileno y la dimerización del 1,1-difeniletileno.
- Las olefinas y los alquinos se sometieron a una hidrosilación eficiente a los alquilisilanos en presencia de los hidrosilanos.
Conclusiones:
- Las sales de organofluorofosfonio son catalizadores efectivos del ácido de Lewis para diversas transformaciones orgánicas.
- La actividad catalítica se atribuye a la estructura electrónica única del catión fosfonio.
- El mecanismo implica la activación secuencial y la adición de 1,2, particularmente en las reacciones de hidrosilación.
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