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Activación rápida intermolecular de C-H de sustratos aromáticos en un complejo catiónico de molibdeno electrófilo:
C Christopher Almquist1, Thayalan Rajeshkumar2, Wen Zhou1
1Department of Chemistry, University of Calgary, 2500 University Dr. NW, T2N 1N4 Calgary, Alberta, Canada.
Journal of the American Chemical Society
|October 27, 2025
Resumen
Los complejos de nitrido de molibdeno activan enlaces C-H en arenas a través de un nuevo mecanismo de sustitución aromática homolítica. Esta vía, de menor energía que los métodos tradicionales, permite nuevas estrategias de transferencia catalítica de átomos de nitrógeno.
Área de la Ciencia:
- Química organometálica
- Catálisis
- Mecanismos de reacción
Sus antecedentes:
- Los complejos de nitrido terminal de molibdeno son conocidos por su reactividad.
- La activación del enlace C-H es una transformación crucial en la química sintética.
- La sustitución aromática electrofílica generalmente se produce a través de productos intermedios del tipo Wheland.
Objetivo del estudio:
- Investigar el mecanismo de activación del enlace C-H por un complejo catiónico de nitruro de Mo.
- Para explorar la formación de complejos de imido de arenas.
- Para aclarar nuevas vías de reacción para la transferencia de átomos de nitrógeno.
Principales métodos:
- Generación de un complejo catiónico de nitrido de Mo (VI) con un ligando pentadentado de diboro.
- Los cálculos de la Teoría Funcional de la Densidad (DFT).
- Estudios experimentales, incluidos los experimentos cruzados.
Principales resultados:
- El complejo de nitrido Mo activa los enlaces C sp 2 H de los arenos, formando complejos de imido catiónicos.
- Se identificó un nuevo mecanismo que involucra la sustitución aromática homolítica y un estado de transición singlete de cáscara abierta.
- Esta nueva vía es entálpicamente favorecida sobre los mecanismos de sustitución aromática electrofílica tradicionales.
Conclusiones:
- Se ha descubierto un nuevo mecanismo para la activación de C-H por complejos de nitridos terminales electrófilos.
- Esta vía ofrece rutas de energía más bajas para la transferencia de átomos de nitrógeno a enlaces C-H.
- Los hallazgos abren vías para el desarrollo de nuevos sistemas catalíticos para la funcionalización de C-H.
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