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La activación de alquinos terminales por pares frustrados y clásicos ácido de Lewis/fosfina
Meghan A Dureen1, Douglas W Stephan
1Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, Canada, M5S 3H6.
Journal of the American Chemical Society
|June 3, 2009
Resumen
Los pares de Lewis frustrados y los pares de Lewis clásicos reaccionan con alquinas terminales. Estas reacciones forman ya sea sales de alquinilborato a través de la activación de C-H o boratos de zwitteriones de fosfonio a través de la adición de alquino.
Área de la Ciencia:
- Química organometálica Química orgánica de los metales.
- La catálisis es la catálisis.
- Síntesis orgánica La síntesis orgánica.
Sus antecedentes:
- Los pares de Lewis, que comprenden ácidos de Lewis y bases de Lewis, son fundamentales en la química.
- Los pares de Lewis frustrados (FLP) son pares de ácido-base de Lewis no coordinados que conservan la reactividad.
- Los pares clásicos de Lewis implican una fuerte formación de aductos ácido-base de Lewis, lo que limita su reactividad.
Objetivo del estudio:
- Para investigar la reactividad de los pares de Lewis frustrados y clásicos con alquinas terminales.
- Para dilucidar las vías de reacción y los productos formados a partir de estas interacciones.
- Para explorar la utilidad sintética de las reacciones par-alquina de Lewis.
Principales métodos:
- Combinación de ácidos de Lewis (por ejemplo, boranos) con fosfinas para formar pares de Lewis.
- Reacción de estos pares de Lewis con varias alquinas terminales.
- Caracterización de los productos de reacción mediante técnicas espectroscópicas (por ejemplo, RMN) y cristalografía de rayos X.
Principales resultados:
- Los pares de Lewis frustrados y clásicos experimentan reacciones distintas con las alquinas terminales.
- La activación de C-H por pares de Lewis conduce a la formación de sales de alquilborato.
- La adición directa de los pares de Lewis al triple enlace alquino da lugar a los boratos de fosfonio zwitteriónico.
Conclusiones:
- El tipo de par de Lewis (frustrado vs. clásico) dicta el resultado de la reacción con alquinas terminales.
- El estudio revela dos modos de reacción primarios: la activación C-H y la 1,2-adición.
- Estos hallazgos amplían el repertorio sintético para la funcionalización de alquinas utilizando la química de pares de Lewis.
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