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Kevin L Miller¹, Bryan N Williams, Diego Benitez

¹Department of Chemistry & Biochemistry, University of California, Los Angeles, California 90095, USA.

Journal of the American Chemical Society

|December 5, 2009

Resumen

Los complejos benzílicos del grupo 3 median el acoplamiento y la escisión de enlaces C-N en heterociclos N aromáticos. Estos complejos facilitan la migración de alquilo y la transferencia de hidrógeno, con estudios experimentales y computacionales que apoyan un mecanismo concertado.

Área de la Ciencia:

Química organometálica Química orgánica de los metales.
La catálisis es la catálisis.
Síntesis orgánica La síntesis orgánica.

Sus antecedentes:

Los metales del grupo 3 son cada vez más reconocidos por su potencial catalítico.
Los ligandos de diamido de ferroceno ofrecen propiedades electrónicas y estéricas únicas para la estabilización de complejos metálicos.
Los N-heterociclos aromáticos son bloques de construcción vitales en los productos farmacéuticos y la ciencia de los materiales.

Objetivo del estudio:

Para investigar la reactividad de los complejos bencílicos del grupo 3 con N-heterociclos aromáticos.
Explorar los mecanismos de la transferencia de ligandos y la donación de hidrógeno.
Caracterizar los nuevos productos de N-heterociclo dearomatizados y sus reacciones posteriores.

Principales métodos:

Síntesis y caracterización de complejos bencílicos del grupo 3.
Reacciones con los N-heterociclos (2,2'-bipiridina, isoquinolina).
Análisis espectroscópico (AMN) y cristalografía de rayos X.
Cálculos de la Teoría Funcional de Densidad (DFT) para conocimientos mecanicistas.

Principales resultados:

Los complejos benzílicos del grupo 3 median el acoplamiento y la escisión de enlaces C-N de los heterociclos N.
La migración de alquilo del ligando bencilo hacia el anillo de piridina, lo que lleva a la dearomatización.
Los productos actúan como donantes de hidrógeno en presencia de varios sustratos.
Mecanismo concertado propuesto para la transferencia de hidrógeno, respaldado por datos experimentales y computacionales.
Observación de una reacción de desproporcionamiento única para los complejos de isoquinolina dearomatizados.

Conclusiones:

Los complejos benzílicos del grupo 3 son catalizadores versátiles para la funcionalización del heterociclo N.
La migración de alquilo observada y la dearomatización abren nuevas vías sintéticas.
El mecanismo de transferencia de hidrógeno proporciona información fundamental sobre los procesos catalíticos.
Este estudio amplía el alcance de la catálisis organometálica que involucra a los metales del Grupo 3.

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