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La polaridad radical
Jacob J A Garwood1, Andrew D Chen1, David A Nagib1
1Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States.
Journal of the American Chemical Society
|October 4, 2024
Resumen
Comprender la polaridad radical es clave para controlar las reacciones químicas. Este estudio cuantifica la electrophilicidad radical y la nucleophilicidad, creando una base de datos validada experimentalmente para predecir la reactividad y mejorar los resultados sintéticos.
Área de la Ciencia:
- Química orgánica
- Química computacional
- Química Física
Sus antecedentes:
- La polaridad intermedia radical influye significativamente en la reactividad y la selectividad en la síntesis química.
- La predicción y cuantificación de esta influencia es crucial para el desarrollo de la reacción.
Objetivo del estudio:
- Para calcular computacionalmente la electrophilicidad / nucleophilicidad de más de 500 radicales.
- Para validar experimentalmente estas polaridades calculadas para una amplia gama de especies radicales.
- Establecer un modelo predictivo que correlacione la polaridad radical con la reactividad y la selectividad.
Principales métodos:
- Cálculos de la Teoría Funcional de la Densidad (DFT) para determinar la electrofilia/nucleofilia (ω) para más de 500 radicales.
- Validación experimental utilizando experimentos de competencia con más de 50 radicales centrados en C, N y O.
- Análisis de correlación entre la polaridad calculada y la reactividad relativa cuantificada (k_rel).
Principales resultados:
- Una base de datos completa de polaridades radicales computadas para los intermedios sintéticos comunes.
- La validación experimental confirmó altas correlaciones entre la polaridad calculada y la reactividad medida.
- Se observó una fuerte relación entre la electrofilicidad (ω) y la reactividad relativa (k_rel), con pequeños cambios de polaridad que producen mejoras significativas de la velocidad.
Conclusiones:
- La base de datos validada experimentalmente permite una predicción precisa de la reactividad y la selectividad de los radicales.
- El aprovechamiento de la mejora de la velocidad ajustada a la polaridad puede optimizar el desarrollo de la reacción sintética.
- Este recurso ayudará a solucionar problemas y diseñar nuevas vías sintéticas.
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