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Inversión de la quimioselectividad convencional en las arilaciones de aminas catalizadas por Pd con piridinas

Mitchell H Keylor¹, Zachary L Niemeyer², Matthew S Sigman²

¹Global Discovery Chemistry, Novartis Institutes for Biomedical Research , 250 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.

Journal of the American Chemical Society

|July 18, 2017

Resumen

Los investigadores desarrollaron un nuevo catalizador para la funcionalización selectiva de cloruro durante la aminación catalizada por paladio de bromo / cloro piridina. Un nuevo ligando de difosfina, DMAPF, demostró ser muy eficaz en esta difícil transformación química.

Área de la Ciencia:

Química orgánica
Catálisis
Química medicinal

Sus antecedentes:

La aminación catalizada por el paladio es crucial para la formación de enlaces C-N.
La funcionalización selectiva de haluros mixtos (Br/Cl) sigue siendo un desafío sintético.
El desarrollo de ligandos eficientes es clave para mejorar las reacciones catalíticas.

Objetivo del estudio:

Informar de un nuevo sistema catalizador para la funcionalización selectiva del cloruro.
Para optimizar la aminación catalizada por Pd de las piridinas 3,2 y 5,2-Br/Cl.
Para identificar un ligando eficaz para esta transformación.

Principales métodos:

Evaluación de los ligandos de difosfina para la aminación catalizada por Pd.
Parametrización de ligandos para la optimización de la reacción.
Síntesis y caracterización de los derivados de piridina.

Principales resultados:

Identificación del 1,1'-bis[bis(dimetilamino) fosfino]ferroceno (DMAPF) como un ligando muy eficaz.
Se logró la funcionalización selectiva del cloruro en 3,2- y 5,2- Br/Cl-piridinas.
El DMAPF permitió una aminación eficaz catalizada por el paladio en condiciones optimizadas.

Conclusiones:

DMAPF es un ligando novedoso y de eficacia única para la funcionalización selectiva del cloruro en la aminación catalizada por Pd.
El sistema de catalizador desarrollado ofrece una nueva ruta sintética para la funcionalización de sustratos de piridina desafiantes.
Este trabajo amplía el alcance de las reacciones de acoplamiento cruzado selectivo.

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