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Descifrando la dicotomía mecanicista en la ciclización de 1-(2-etinilefenil) -3,3-dialquiltriazenos: la competencia
David B Kimball1, Timothy J R Weakley, Rainer Herges
1Department of Chemistry, University of Oregon, Eugene 97403-1253, USA.
Journal of the American Chemical Society
|November 7, 2002
Resumen
Este estudio explora los mecanismos de ciclización de los (2-etilfenilfenil) triazenos. Diferentes vías, incluidas las vías carbénicas y pericíclicas, conducen a varios productos como los isoindazoles y las cinolinas.
Área de la Ciencia:
- Química orgánica es la química orgánica.
- Mecanismos de reacción Mecanismos de reacción
Sus antecedentes:
- Las reacciones de ciclización son fundamentales en la síntesis orgánica.
- Comprender las vías de reacción es crucial para controlar la formación de productos.
Objetivo del estudio:
- Para dilucidar las vías mecanicistas de la ciclización del (2-etinilefenil) triazeno.
- Para investigar las condiciones de reacción tanto térmica como mediada por cobre.
- Para identificar los principales intermediarios y productos de reacción.
Principales métodos:
- Estudios experimentales sobre (2-etinilefenil) triazenos bajo condiciones térmicas y mediadas por cobre.
- Cálculos de la teoría de la densidad-funcional (DFT).
- Estudios de atrapamiento de deuterio.
Principales resultados:
- Se propone una vía de carbeno para la formación de isoindazol, con intermediarios susceptibles al oxígeno, la dimerización o el atrapamiento.
- Los cálculos de DFT apoyan una vía de pseudocoarctato para la formación de carbenos.
- Se propone una vía pericíclica para la formación de cinolina a través de un intermediario de zwitterionic dehydrocinnolinium, con el apoyo de la captura experimental.
Conclusiones:
- La ciclización de los (2-etilfenilfenil) triazenos procede a través de distintas vías mecánicas dependiendo de las condiciones.
- Las vías carbenicas y pericíclicas dictan la formación de diferentes productos heterocíclicos.
- Los datos computacionales y experimentales proporcionan un fuerte apoyo a los mecanismos propuestos.
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