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Alquilación selectiva sp³ C-H mediante acoplamiento cruzado basado en coincidencia de polaridad

Chip Le¹, Yufan Liang¹, Ryan W Evans¹

¹Merck Center for Catalysis at Princeton University, Princeton, New Jersey 08544, USA.

|June 22, 2017

Resumen

Este estudio introduce un nuevo método para la alquilación selectiva de sp3 C-H, reemplazando los átomos de hidrógeno por grupos alquilo. El enfoque utiliza fotorredóxido, níquel y catálisis de transferencia de átomos de hidrógeno para una construcción molecular eficiente.

Área de la Ciencia:

Química orgánica
Catálisis
Metodología sintética

Sus antecedentes:

La funcionalización del enlace carbono-hidrógeno (C-H) es crucial para la construcción molecular.
Hay una necesidad significativa de alquilación sp3 C-H para introducir grupos C-alquilo sp3.
Los métodos existentes a menudo se centran en el acoplamiento C ((sp3) -C ((sp2)), dejando una brecha para las transformaciones de enlaces C-H sp3.

Objetivo del estudio:

Desarrollar un método selectivo para la alquilación de C-H sp3.
Para permitir la sustitución de los enlaces sp3 C-H por grupos sp3 C-alquilo.
Proporcionar una herramienta versátil para sintetizar moléculas orgánicas complejas.

Principales métodos:

Una nueva estrategia basada en la coincidencia de polaridad para la alquilación selectiva de sp3 C-H.
Integración de fotorredóxido, níquel y catálisis de transferencia de átomos de hidrógeno.
Funcionamiento simultáneo de tres ciclos catalíticos para la funcionalización C-H y el acoplamiento alquilo-alquilo.

Principales resultados:

Se obtiene una alquilación selectiva de sp3 C-H mediante la abstracción de enlaces hidridos C-H y el acoplamiento de fragmentos alquilo-alquilo.
Se ha demostrado una alta selectividad para los enlaces α-C-H de aminas, éteres y sulfuros.
El método es aplicable a las arquitecturas moleculares farmacéuticamente relevantes.

Conclusiones:

El protocolo de acoplamiento cruzado desarrollado ofrece un nuevo y poderoso enfoque para la síntesis orgánica.
Esta metodología facilita tanto la síntesis de novo como la funcionalización en las últimas etapas.
La alquilación selectiva sp3 C-H expande el conjunto de herramientas para crear moléculas complejas.

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