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Invertir los efectos estéricos: el uso de interacciones no covalentes "atractivas" para dirigir la transferencia de

Minxue Huang¹, Tzuhsiung Yang¹, Jonathan D Paretsky¹

¹Department of Chemistry, University of Wisconsin , Madison, Wisconsin 53706, United States.

Journal of the American Chemical Society

|November 2, 2017

Resumen

Este estudio revela cómo las interacciones no covalentes guían la selectividad del catalizador en las reacciones de transferencia de nitreno, lo que permite una aminación precisa de C-H para la síntesis química. Estos hallazgos ayudan a diseñar mejores catalizadores para importantes formaciones de enlaces C-N.

Área de la Ciencia:

Catálisis
Química orgánica
Química computacional

Sus antecedentes:

Las reacciones de transferencia de nitreno (NT) son vitales para la aminación C-H, crucial en productos farmacéuticos y químicos.
Los catalizadores de metales de transición se desarrollan para el NT selectivo, pero la comprensión de la selectividad del sitio sigue siendo un desafío.

Objetivo del estudio:

Investigar la selectividad de Ag(tpa) OTf en la activación de enlaces C-H conjugados sobre enlaces alquilo C(sp3)-H terciarios.
Elucidar el papel de las interacciones no covalentes (ICN) en la dirección de la selectividad de la aminación C-H.
Aplicar conocimientos para optimizar las reacciones y diseñar nuevos catalizadores.

Principales métodos:

Estudios experimentales para sondear las interacciones catalizador-sustrato.
Modelado computacional (DFT) para analizar estados de transición y vías de reacción.
Desarrollo de un modelo predictivo basado en la ley de Hess para la selectividad.

Principales resultados:

Ag ((tpa) OTf activa preferentemente los enlaces α-conjugados C-H.
Las interacciones no covalentes, incluidas π··π y Ag··π, influyen significativamente en la selectividad.
Los estudios computacionales confirman el papel de los INC en la estabilización de los estados de transición dirigidos.
El enfoque basado en la ley de Hess predice con precisión la selectividad para nuevos sustratos.

Conclusiones:

Las interacciones no covalentes son determinantes clave de la selectividad del sitio en las reacciones de NT catalizadas por Ag.
La comprensión de estas interacciones facilita el diseño racional del catalizador para la funcionalidad C-H.
Los resultados proporcionan un marco para el desarrollo de estrategias de aminación selectiva de C-H.

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