Yang Kai, Luo Shi-He, Chen Si-Hong, Cao Xi-Ying, Zhou Yong-Jun, Lin Yan-Lan, Huo Yan-Ping, Wang Zhao-Yang
School of Chemistry, South China Normal University, Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, Guangzhou Key Laboratory of Analytical Chemistry for Biomedicine, Guangzhou 510006, P. R. China.
College of pharmacy, Gannan Medical University, Ganzhou 341000, P. R. China.
Org Biomol Chem. 2021 Sep 29;19(37):8133-8139. doi: 10.1039/d1ob01424b.
Metal-free catalyzed intermolecular tandem Michael addition/cyclization has been developed for the synthesis of benzo[4,5]imidazo[1,2-]pyridines from α-bromocinnamaldehyde and 2-substituted benzimidazoles. The reaction promoted by a simple inorganic base displays moderate to good yields and good functional group tolerance. The optical properties of some typical products have been investigated. We found that, due to the presence of the benzene ring at the C1-position of benzo[4,5]imidazo[1,2-]pyridines which restricts intramolecular motion, as a new type of aggregation-induced emission (AIE) luminogen (AIEgen), they show very good solid-state fluorescence with quantum yields up to 88.80%. Importantly, the AIE performance of compound 3b can be useful to detect the nitroaromatic explosive picric acid (PA) with a detection limit and quenching constant of 42.5 nM and 7.27 × 10 M, respectively.
已开发出无金属催化的分子间串联迈克尔加成/环化反应，用于从α-溴肉桂醛和2-取代苯并咪唑合成苯并[4,5]咪唑并[1,2 - ]吡啶。由简单无机碱促进的该反应具有中等至良好的产率和良好的官能团耐受性。已对一些典型产物的光学性质进行了研究。我们发现，由于苯并[4,5]咪唑并[1,2 - ]吡啶的C1位存在苯环，限制了分子内运动，作为一种新型的聚集诱导发光（AIE）发光体（AIEgen），它们显示出非常好的固态荧光，量子产率高达88.80%。重要的是，化合物3b的AIE性能可用于检测硝基芳香族炸药苦味酸（PA），检测限和猝灭常数分别为42.5 nM和7.27×10 M。
