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Estudios espectroscópicos de la aminación Chan-Lam: una solución inspirada en el mecanismo de la reactividad del
Julien C Vantourout1,2, Haralampos N Miras3, Albert Isidro-Llobet2
1Department of Pure and Applied Chemistry, WestCHEM, University of Strathclyde , Glasgow G1 1XL, United Kingdom.
Journal of the American Chemical Society
|March 8, 2017
Resumen
Este estudio revela el mecanismo de la reacción de aminación de Chan-Lam, identificando los intermedios clave y las reacciones secundarias. Las soluciones se desarrollaron manipulando los estados de oxidación del cobre y utilizando ácido bórico, lo que permitió una aminación catalítica general.
Área de la Ciencia:
- Química orgánica
- Catálisis
- Mecanismos de reacción
Sus antecedentes:
- La aminación Chan-Lam es una reacción de acoplamiento cruzado crucial para la formación de enlaces C-N.
- Las limitaciones anteriores incluían desafíos con el alcance y la reactividad del sustrato de aminas y organoboron.
- Faltaba una comprensión mecanicista completa.
Objetivo del estudio:
- Para aclarar el mecanismo de reacción detallado de la aminación de Chan-Lam.
- Identificar los orígenes de los problemas de reactividad y las reacciones secundarias.
- Desarrollar un mejorado protocolo catalítico general de aminación Chan-Lam.
Principales métodos:
- Técnicas espectroscópicas (por ejemplo, RMN, EPR) para la identificación intermedia.
- Modelado computacional (por ejemplo, DFT) para sondear las vías de reacción.
- Cristalografía de rayos X para determinar las estructuras intermedias.
Principales resultados:
- Se caracterizaron estructuralmente los intermediarios clave de la reacción.
- Se aclararon las vías mecánicas, incluidos los procesos fuera del ciclo y las reacciones secundarias (oxidación, protodeboronación).
- Se aclararon las funciones de los estados de oxidación del cobre (Cu ((I) / Cu ((II)) y el ácido bórico.
Conclusiones:
- Se estableció un modelo mecanicista completo para la aminación de Chan-Lam.
- La manipulación estratégica del ciclo redox del cobre y los efectos sinérgicos del ácido bórico resuelven las limitaciones del sustrato.
- Se desarrolló con éxito una reacción de aminación catalítica general y mejorada de Chan-Lam.
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