Photochemical synthesis of indazolo[3,2-b]quinazolines and their redox-switching properties
作者:Shi-Chen Li、Wei-Fang Jhang、Teau-Jiuan Liou、Ding-Yah Yang
DOI:10.1016/j.dyepig.2014.11.020
日期:2015.3
Several indazolo[3,2-b]quinazolines were synthesized in moderate to good yields by exposing 2-(2-nitrophenyl)-1,2,3,4-tetrahydroquinazolines to UV light (306 nm) in acetonitrile. The scope, limitation, and possible mechanism of this light-mediated reaction as well as the redox-switching properties of the target compounds were explored. Reduction of the colored indazolo[3,2-b]quinazoline with sodium borohydride resulted in a distinct change to colorless and a sharp increase in fluorescence intensity. The reduced product can be swiftly reverted to the original form by 2,3-dichloro-5,6-dicyano-1,4-benzoquinone oxidation. The reversible redox-switching between the indazolo[3,2-b]quinazoline and its reduced product utilizing chemical reduction and oxidation as two external stimuli with dual output properties; that is, color change and emission variation was reported. (C) 2014 Elsevier Ltd. All rights reserved.