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Estéricos y control de enlaces de hidrógeno Estereoquímica y autoclasificación en ensamblajes basados en BINOL
You-Quan Zou1, Dawei Zhang1, Tanya K Ronson1
1Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom.
Journal of the American Chemical Society
|June 14, 2021
Resumen
El enlace de hidrógeno en los dialdehídos basados en BINOL controla el autoensamblaje en estructuras helicadas específicas. La metilación altera el comportamiento de autoclasificación y la quiralidad axial dicta el centro de la mano del metal, lo que permite nuevos helicatos estereoquímicamente puros.
Área de la Ciencia:
- Química supramolecular
- Síntesis orgánica
- Química de coordinación
Sus antecedentes:
- Los derivados de Chiral BINOL son bloques de construcción valiosos en la química supramolecular.
- El control de la estereoquímica en el autoensamblaje es crucial para crear arquitecturas moleculares funcionales.
- Comprender el comportamiento de autoclasificación es clave para diseñar sistemas complejos multicomponentes.
Objetivo del estudio:
- Investigar cómo la capacidad de enlace de hidrógeno y la metilación de un dialdehído a base de BINOL influyen en los resultados de autoensamblaje.
- Explorar el impacto de estas modificaciones en el comportamiento de autoclasificación con ligandos lineales.
- Preparar nuevos helicatos heteroleptos estereocímicamente puros mediante el control de la quiralidad y el ensamblaje.
Principales métodos:
- Síntesis de subcomponentes de dialdehído a base de BINOL con y sin grupos metilo.
- Estudios de autoensamblaje en presencia de iones metálicos (FeII, ZnII).
- Análisis del comportamiento de autoclasificación utilizando técnicas como la espectroscopia de RMN y la espectrometría de masas.
Principales resultados:
- Los grupos hidroxi libres en el dialdehído promueven una forma de helicato diastereomérico, mientras que la metilación conduce a otra.
- La metilación cambia la autoclasificación de narcisista a integradora cuando se mezcla con un dialdehído lineal.
- La quiralidad axial de la unidad BINOL dicta consistentemente el centro de la mano del metal helicado.
- Se sintetizaron con éxito nuevos helicatos heteroleptos estereoquímicamente puros.
- El cambio de iones metálicos (FeII a ZnII) o el uso de ligandos lineales más largos favorece la formación de helicatos heterolépticos.
Conclusiones:
- El enlace de hidrógeno y la metilación son factores críticos que controlan la estereoquímica y la autoclasificación en los sistemas basados en BINOL.
- La transferencia de quiralidad axial es una característica robusta durante el autoensamblaje estereospecífico.
- Los hallazgos permiten el diseño y la síntesis racionales de nuevos helicatos heterolépticos estereoquímicamente puros.
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