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Lactonización catalítica altamente enantioselectiva en enlaces primarios y secundarios no activados

Arnau Call¹, Giorgio Capocasa¹, Andrea Palone¹

¹Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Campus Montilivi, Girona E-17071, Catalonia, Spain.

Journal of the American Chemical Society

|August 4, 2023

Resumen

Los investigadores desarrollaron un nuevo método para crear gamma-lactonas quirales utilizando catalizadores de manganeso y peróxido de hidrógeno. Esta oxidación enantioselectiva eficiente de los enlaces C-H produce valiosos intermedios para productos naturales y polímeros.

Área de la Ciencia:

Química orgánica
Catálisis
Metodología sintética

Sus antecedentes:

Las fracciones alifáticas oxigenadas quirales son bloques de construcción cruciales en compuestos biológicamente activos y productos farmacéuticos.
La síntesis eficiente de gamma-lactonas quirales es esencial para acceder a arquitecturas moleculares complejas.
Los métodos existentes para la oxidación enantioselectiva a menudo requieren sustratos específicos o condiciones adversas.

Objetivo del estudio:

Desarrollar un protocolo general y sencillo para la síntesis enantioselectiva de gamma-lactonas quirales.
Para permitir la oxidación directa de enlaces primarios y secundarios no activados en ácidos carboxílicos.
Utilizar catalizadores de manganeso robustos y altamente selectivos para esta transformación.

Principales métodos:

Oxidación enantioselectiva de ácidos carboxílicos mediante el uso de catalizadores de manganeso estérico.
El uso de peróxido de hidrógeno como un oxidante verde y eficiente.
Se centrará en la funcionalización directa de los enlaces primarios y secundarios C ((sp) -H no activados.

Principales resultados:

Se han logrado enantiselectividades sobresalientes, hasta >99,9% ee.
Se obtienen altos rendimientos químicos, hasta el 96%.
Demostró una aplicabilidad general del protocolo a varios ácidos carboxílicos.

Conclusiones:

El protocolo desarrollado proporciona una vía versátil y altamente eficiente para las gamma-lactonas quirales.
Este método ofrece acceso directo a valiosos productos intermedios quirales a partir de materiales de partida fácilmente disponibles.
Las gamma-lactonas resultantes son útiles para la síntesis de productos naturales y polímeros reciclables.

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