Design of Redox/Radical Sensing Molecules via Nitrile Imine-Mediated Tetrazole-ene Cycloaddition (NITEC).
J Org Chem
; 80(16): 8009-17, 2015 Aug 21.
Article
en En
| MEDLINE
| ID: mdl-26168007
ABSTRACT
The current study introduces a novel synthetic avenue for the preparation of profluorescent nitroxides via nitrile imine-mediated tetrazole-ene cycloaddition (NITEC). The photoinduced cycloaddition was performed under metal-free, mild conditions allowing the preparation of a library of the nitroxide functionalized pyrazolines and corresponding methoxyamines. High reaction rates and full conversion were observed, with the presence of the nitroxide having no significant impact on the cycloaddition performance. The formed products were investigated with respect to their photophysical properties in order to quantify their "switch on/off" behavior. The fluorescence quenching performance is strongly dependent on the distance between the chromophore and the free radical spin as demonstrated theoretically and experimentally. Highest levels of fluorescence quenching were achieved for pyrazolines with the nitroxide directly fused to the chromophore. Importantly, the pyrazoline profluorescent nitroxides were shown to efficiently act as sensors for redox/radical processes.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Tetrazoles
/
Iminas
/
Nitrilos
/
Óxidos de Nitrógeno
Idioma:
En
Revista:
J Org Chem
Año:
2015
Tipo del documento:
Article
País de afiliación:
Australia