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Arilación doble C-H electrooxidativa catalizada por el paladio
Zhipeng Lin1,2, João C A Oliveira1,2, Alexej Scheremetjew1,2
1Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstraße 2, 37077 Göttingen, Germany.
Journal of the American Chemical Society
|December 27, 2023
Resumen
Este estudio introduce un método electroquímico catalizado por el paladio para sintetizar biarilos sin oxidantes químicos. Los estudios mecánicos revelan que la transmitación entre los complejos de organopaladio es clave para esta estrategia de síntesis orgánica sostenible.
Área de la Ciencia:
- La electroquímica
- Síntesis orgánica
- Catálisis
Sus antecedentes:
- Las reacciones electroquímicas cruzadas deshidrogenativas ofrecen una síntesis sostenible pero carecen de claridad mecanicista.
- La adopción generalizada se ve obstaculizada por la escasa comprensión de las vías de reacción.
Objetivo del estudio:
- Desarrollar un acoplamiento oxidativo electroquímico catalizado por el paladio para la síntesis de biarilo.
- Para aclarar el mecanismo de reacción e identificar los factores clave para el éxito.
Principales métodos:
- Acoplamiento oxidativo electroquímico catalizado por el paladio.
- Estudios mecánicos que incluyen análisis de normalización en tiempo variable (VTNA), análisis de velocidad inicial, intercambio H/D, efecto de isótopos cinéticos y experimentos organometálicos.
- Funcionalización y síntesis en etapa tardía del precursor de Boscalid.
Principales resultados:
- Desarrolló una robusta paladaelectrocatálisis para la síntesis de biarilo, evitando los oxidantes estequiométricos.
- Se suprime el homoacoplamiento y la oxigenación, lo que demuestra la compatibilidad con las arenas con déficit de electrones.
- Los estudios mecanicistas confirmaron la transmesación entre dos complejos de organopaladio en la etapa de limitación de la rotación.
Conclusiones:
- La coincidencia de las concentraciones o de la vida útil de los intermediarios de organopaladio es crucial para la catálisis electrooxidativa.
- El cobre catiónico (II) estabiliza el catalizador de paladio en lugar de participar en la oxidación.
- El método desarrollado es práctico para la funcionalización en etapa tardía y la síntesis de precursores.
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