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Los intermediarios de pre-transmetalización en la reacción Suzuki-Miyaura revelados: El eslabón perdido
Andy A Thomas1, Scott E Denmark2
1Roger Adams Laboratory, Department of Chemistry, University of Illinois, Urbana, IL 61801, USA.
Science (New York, N.Y.)
|April 16, 2016
Resumen
Los investigadores identificaron los intermediarios clave en las reacciones de acoplamiento cruzado Suzuki-Miyaura. Este estudio revela la estructura de los complejos de paladio-oxígeno-boro involucrados en la transmitación, aclarando un paso crucial en la formación de enlaces carbono-carbono.
Área de la Ciencia:
- Química orgánica
- Química organometálica
- Catálisis
Sus antecedentes:
- El acoplamiento cruzado Suzuki-Miyaura es vital para crear enlaces carbono-carbono.
- Las estructuras exactas de los productos intermedios durante la etapa de transmesación no se conocen bien.
Objetivo del estudio:
- Identificar y caracterizar los intermediarios reactivos evasivos en el paso de transmisión Suzuki-Miyaura.
- Para aclarar los detalles estructurales de los complejos de boro y paladio.
Principales métodos:
- Se utilizó la espectroscopia de resonancia magnética nuclear de inyección rápida a baja temperatura (RMN).
- Se realizaron estudios cinéticos para observar y analizar los intermedios de reacción.
- Enlaces de paladio-oxígeno-boro y complejos de ácido borónico/boronato caracterizados.
Principales resultados:
- Se identificaron tres especies distintas con enlaces de paladio-oxígeno-boro.
- Se caracterizó un complejo de ácido borónico tricoordinado y dos complejos de boronato tetracoordinado (2: 1 y 1: 1 Pd: estequiometría de boro).
- Se ha confirmado que estas especies identificadas transfieren grupos ariles que contienen boro al paladio.
Conclusiones:
- El estudio proporciona una identificación estructural definitiva de los intermediarios clave en la transmisión de Suzuki-Miyaura.
- La comprensión de estos intermedios avanza el conocimiento de las reacciones de acoplamiento cruzado catalizadas por paladio.
- Este trabajo aclara el mecanismo de transferencia del grupo arilo del boro al paladio.
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