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Updated: May 29, 2025
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Regioselective O-Glycosylation of Nucleosides via the Temporary 2',3'-Diol Protection by a Boronic Ester for the Synthesis of Disaccharide Nucleosides
Published on: July 26, 2018
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La estereoselectividad de la glicosilación dirigida por grupos vecinos es dependiente de la concentración
Pallabita Basu1,2, David Crich1,2,3
1Department of Pharmaceutical and Biomedical Sciences, University of Georgia, 250 West Green Street, Athens, Georgia 30602, United States.
Journal of the American Chemical Society
|February 5, 2025
Resumen
La optimización de las reacciones de glucosilación requiere un control cuidadoso de la concentración y la estequiometría. El ajuste de estos parámetros puede mejorar significativamente la selectividad de la formación de 1,2-trans-glucósidos, un proceso clave en la química de los carbohidratos.
Área de la Ciencia:
- Química de los carbohidratos
- Síntesis orgánica
Sus antecedentes:
- La participación de grupos vecinos por ésteres de 2 posiciones es una estrategia común para formar 1,2-trans-glucósidos.
- Sin embargo, a menudo se observa una selectividad imperfecta, que requiere métodos alternativos o elecciones de ésteres.
Objetivo del estudio:
- Investigar el impacto de la concentración de reacción y la estequiometría en la glicosilación dirigida por grupos vecinos.
- Para demostrar cómo el ajuste de estos factores puede mejorar la 1,2-trans-selectividad.
Principales métodos:
- Se examinaron tres estudios de caso de reacciones de glicosilación dirigidas a los glicosidos 1,2-trans-equatorial y 1,2-trans-axial.
- Estequiometría variada del aceptor: donante y concentración global de la reacción.
Principales resultados:
- Las concentraciones más altas, obtenidas aumentando la estequiometría o los niveles de reactivo, generalmente reducen la 1,2-transselectividad.
- Esta disminución en la selectividad se atribuye a un aumento en la glicosilación de tipo SN2 con donantes covalentes.
Conclusiones:
- La concentración de reacción y la estequiometría son factores críticos que influyen en la selectividad en la glicosilación dirigida por grupos vecinos.
- El paso a un régimen de concentración diferente ofrece un método sencillo para mejorar la transselectividad del 1,2 en casos difíciles.
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