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Estudio DFT sobre la alilación catalizada por el paladio de aminas primarias por alcohol alílico

Olivier Piechaczyk¹, Claire Thoumazet, Yves Jean

¹Laboratoire Hétéroéléments et Coordination, UMR CNRS 7653, Ecole Polytechnique, 91128 Palaiseau Cedex, France.

Journal of the American Chemical Society

|November 2, 2006

Resumen

Los cálculos de DFT revelan un mecanismo favorecido para la alilación catalizada por el paladio de aminas primarias, que implica la descomplejación del alilamonio. La elección del ligando impacta significativamente en la eficiencia, con fuertes pi-aceptores que mejoran la reacción.

Área de la Ciencia:

Química organometálica Química orgánica de los metales.
La catálisis de la catálisis.
Química computacional es la química computacional.

Sus antecedentes:

La alilación catalizada por paladio es crucial para la síntesis de aminas funcionalizadas.
La comprensión de los mecanismos de reacción es clave para optimizar la eficiencia catalítica.

Objetivo del estudio:

Investigar el mecanismo de la alilación catalizada por el paladio de aminas primarias utilizando cálculos DFT.
Identificar los factores que influyen en la actividad catalítica, en particular los efectos de ligando.

Principales métodos:

Se emplearon cálculos de la Teoría Funcional de Densidad (DFT) (método B3PW91, PCM).
Se exploraron y compararon dos posibles mecanismos de reacción.
El análisis de descomposición de carga (CDA) se utilizó para evaluar las propiedades electrónicas de los ligandos.

Principales resultados:

Se prefiere un mecanismo que implique la descomplejación de alilamonio en lugar de uno con intermediarios catiónicos de hidridopalladio.
El rendimiento del catalizador es fuertemente dependiente de las propiedades del ligando; fuertes ligandos pi-aceptores promueven la descomplejación.
Se identificó experimentalmente un catalizador eficiente, [Pd(P(OPh) ((3)) ((2) ((eta ((3) -C ((3) H)) ((5)) ], fue identificado experimentalmente.

Conclusiones:

El mecanismo favorecido para la alilación catalizada por el paladio de aminas primarias implica la descomplejación.
El diseño de los ligandos es crítico para mejorar la actividad catalítica en las reacciones de alilación.
La eficiencia del catalizador es sensible a la basicidad de aminas, con aminas menos básicas que favorecen la regeneración de precursores.

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