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Reacciones de acoplamiento cruzado asistido por silicio intramolecular: síntesis general de anillos de tamaño mediano
Scott E Denmark1, Shyh-Ming Yang
1Roger Adams Laboratory, Department of Chemistry, University of Illinois, 600 South Mathews Avenue, Urbana, Illinois 61801, USA.
Journal of the American Chemical Society
|March 7, 2002
Resumen
Una nueva estrategia sintética combina la metátesis de cierre de anillos y el acoplamiento catalizado por paladio para crear de manera eficiente anillos de tamaño medio que contienen unidades de dieno. Este método ofrece una nueva y poderosa ruta para sintetizar moléculas orgánicas cíclicas complejas.
Área de la Ciencia:
- Química orgánica es la química orgánica.
- Metodología sintética de la metodología sintética.
- La catálisis de la catálisis.
Sus antecedentes:
- La construcción de anillos de tamaño medio (9-12 miembros) sigue siendo un desafío sintético.
- Los métodos existentes a menudo carecen de eficiencia o amplia aplicabilidad para estructuras complejas.
Objetivo del estudio:
- Desarrollar un método novedoso y eficaz para sintetizar anillos de tamaño mediano.
- Para incorporar una unidad interna de 1,3-cis-cis dieno en los anillos objetivo.
- Explorar el alcance y las limitaciones del nuevo enfoque sintético.
Principales métodos:
- Utilizó una combinación de metátesis de cierre de anillo catalizada por molibdeno (RCM) y acoplamiento cruzado intramolecular asistido por silicio catalizado por paladio.
- Los alcoholes alílicos con Z-iodoalkenil tethers fueron sililados y sometidos a RCM para formar siloxanos insaturados.
- Los siloxanos fueron activados con fluoruro de tetrabutylamonio y [allylPdCl] para reacciones posteriores de cierre de anillo.
Principales resultados:
- Sintetizó con éxito anillos de 9, 10, 11 y 12 miembros que contienen una unidad de 1,3-cis-cis dieno.
- Alcanzó altos rendimientos en las reacciones de cierre de anillos.
- Amplió la metodología para sintetizar éteres insaturados de anillo de 9 miembros.
- Demostró un proceso de acoplamiento intramolecular altamente estereospecífico.
Conclusiones:
- El método desarrollado proporciona una ruta eficaz y potente para la construcción de anillos de tamaño mediano con unidades internas de dieno.
- El proceso ofrece flexibilidad en el posicionamiento del grupo hidroxilo y potencial para sintetizar diversos carbociclos y heterociclos.
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