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3-piridilcarbeno y 3-piridilnitreno: el anillo se abre a los ilidos de nitrilo
1Contribution from the Department of Chemistry, School of Molecular and Microbial Sciences, The University of Queensland, Brisbane, Qld 4072, Australia.
Journal of the American Chemical Society
|September 17, 2004
Resumen
La fotólisis de 3-piridildiazometano y 3-azidopiridina en matrices de argón produce piridilcarbeno y ylidos de nitrilo. Estas reacciones demuestran nuevas vías de apertura de anillos en la fotoquímica heterocíclica.
Área de la Ciencia:
- La fotoquímica es la fotoquímica.
- Química orgánica es la química orgánica.
- Espectroscopia de aislamiento de matriz Espectroscopia de aislamiento de matriz
Sus antecedentes:
- El 3-piridildiazometano y la 3-azidopiridina son precursores de los intermediarios reactivos.
- La fotólisis en matrices inertes permite el estudio de especies inestables a bajas temperaturas.
Objetivo del estudio:
- Para investigar los productos de fotólisis del 3-piridildiazometano y la 3-azidopiridina.
- Para dilucidar los mecanismos de reacción, incluida la apertura del anillo y la expansión del anillo, de estos derivados de piridina en condiciones fotolíticas.
Principales métodos:
- Espectroscopia de aislamiento de matriz a 7-10 K.
- Fotólisis mediante irradiación UV.
- Análisis de los productos de reacción mediante métodos espectroscópicos.
Principales resultados:
- La fotólisis del 3-piridildiazometano generó el 3-piridilcarbeno, que se sometió a una fotólisis adicional para obtener el nitrilo ylide 26 (formonitril pent-2-en-4-inilido) como el producto principal y el 1-azaciclohepta-1,3,4,6-tetraeno (27) como un producto secundario.
- La fotólisis de la matriz de la 3-azidopiridina dio lugar a la apertura del anillo al formonitrilo N-cianovinilmetilido (33).
Conclusiones:
- La fotólisis de los derivados de piridina en matrices de argón proporciona una ruta a los únicos ylidos de nitrilo y otros compuestos heterocíclicos.
- Las reacciones de apertura de anillos son vías significativas para estos procesos de fotólisis, que conducen a diversas estructuras moleculares.
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