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Acoplamiento decarboxilativo electrocatalítico Nozaki-Hiyama-Kishi: alcance, aplicaciones y mecanismo
Yang Gao1, Baiyang Jiang1, Nathan C Friede2
1Department of Chemistry, Scripps Research, 10550 North Torrey Pines Road, La Jolla, California 92037, United States.
Journal of the American Chemical Society
|February 7, 2024
Resumen
Los investigadores desarrollaron el primer acoplamiento enantioselectivo de alquilo-Nozaki-Hiyama-Kishi (NHK) utilizando electrocatálisis. Este método sintetiza eficientemente los alcoholes secundarios quirales a partir de ácidos carboxílicos y aldehídos, simplificando la síntesis de moléculas complejas.
Área de la Ciencia:
- Química orgánica
- Catálisis
- Química ecológica
Sus antecedentes:
- La reacción Nozaki-Hiyama-Kishi (NHK) es una herramienta valiosa para la formación de enlaces C-C.
- El desarrollo de variantes enantioselectivas de las reacciones NHK es crucial para sintetizar moléculas quirales.
- Las reacciones NHK tradicionales a menudo requieren reductores estequiométricos, lo que plantea desafíos ambientales y de eficiencia.
Objetivo del estudio:
- Para revelar la primera reacción de acoplamiento general de alquilo-Nozaki-Hiyama-Kishi (NHK).
- Establecer un nuevo enfoque descarboxilador electrocatalítico para la síntesis asimétrica.
- Proporcionar una alternativa más suave y sostenible a los protocolos NHK existentes.
Principales métodos:
- Utilizando una estrategia descarboxiladora electrocatalítica de cromo (Cr).
- Utilizando ácidos carboxílicos alifáticos fácilmente disponibles (como ésteres redox-activos) como sintones alquilo nucleófilos.
- Realización de la reacción en condiciones de electrólisis reductora suave con tetráquido catalítico (dimetilamino) etileno como mediador reductor.
Principales resultados:
- Se obtienen buenos rendimientos y una alta enantioselectividad en la síntesis de alcoholes secundarios quirales.
- Se ha demostrado una amplia tolerancia del grupo funcional.
- Aplicó con éxito la reacción para simplificar la síntesis de estructuras médicamente relevantes y productos naturales.
- Los estudios mecanicistas confirmaron el papel del tetráquido-dimetilaminoetileno catalítico en la electrorreducción del complejo de ligando Cr-III/chiral.
Conclusiones:
- El enfoque descarboxilador electrocatalítico de Cr desarrollado representa un avance significativo en el acoplamiento asimétrico de NHK.
- Este método electrocatalítico ofrece una vía sostenible y eficiente para los alcoholes secundarios quirales.
- La aplicabilidad de la reacción a la síntesis de moléculas complejas destaca su utilidad práctica en la química medicinal y la síntesis de productos naturales.
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