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Reacciones deshidrogenativas divergentes controladas por ligandos de ácidos carboxílicos a través de la activación

Zhen Wang¹, Liang Hu¹, Nikita Chekshin¹

¹The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92037, USA.

Science (New York, N.Y.)

|November 11, 2021

Resumen

Este estudio introduce nuevos ligandos piridina-piridona para la deshidrogenación catalizada por el paladio de ácidos carboxílicos a través de la activación del metileno CH. Este método permite la síntesis selectiva de ácidos insaturados y butenolidos, superando los principales desafíos sintéticos.

Área de la Ciencia:

Química orgánica
Catálisis
Metodología sintética

Sus antecedentes:

La activación de metileno carbono-hidrógeno (CH) para la deshidrogenación es un desafío.
La síntesis directa de alquenos de las cadenas alquilo requiere estrategias eficientes de activación de CH.

Objetivo del estudio:

Desarrollar nuevos ligandos para la deshidrogenación catalizada por el paladio de ácidos carboxílicos.
Para lograr la síntesis quimioselectiva de ácidos carboxílicos α,β insaturados y butenolidos de γ-alquilideno.

Principales métodos:

Se utilizaron dos clases de ligandos piridina-piridona.
Se utiliza la catálisis con paladio para la activación de ácidos carboxílicos por β-metileno CH.
Se ha investigado la quimioselectividad en presencia de cetonas.

Principales resultados:

Se ha logrado la síntesis directa de ácidos carboxílicos α,β insaturados y butenolidos de γ-alquilideno.
Se ha demostrado la deshidrogenación quimioselectiva de los ácidos carboxílicos sobre las cetonas.
Superó la inhibición del producto promoviendo la activación del enlace C ((sp3) H.

Conclusiones:

Desarrolló un sistema catalítico versátil para la deshidrogenación del ácido carboxílico.
El diseño del ligando permite una funcionalización selectiva y eficiente de CH.
La compatibilidad con el oxígeno molecular como oxidante terminal mejora la practicidad.

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