State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering , Hunan University , 410082 Changsha , P. R. China.
Department of Chemistry , KTH-Royal Institute of Technology , Teknikringen 36 , SE-100 44 Stockholm , Sweden.
J Org Chem. 2019 Nov 15;84(22):14520-14528. doi: 10.1021/acs.joc.9b02050. Epub 2019 Oct 29.
Molecules, capable of fluorescence turn-on by light, are highly sought-after in spatio-temporal labeling, surface patterning, monitoring cellular and molecular events, and high-resolution fluorescence imaging. In this work, we report a fluorescence turn-on system based on photoinitiated intramolecular C-H insertion of azide into the neighboring aromatic ring. The azide-masked fluorogens were efficiently synthesized via a cascade nucleophilic aromatic substitution of perfluoroaryl azides with carbazoles. The scaffold also allows for derivatization with biological ligands, as exemplified with d-mannose in this study. This photoinitiated intramolecular transformation led to high yields, high photo-conversion efficiency, and well-separated wavelengths for photoactivation and fluorescence excitation. The mannose-derivatized structure enabled spatio-temporal activation and showed high contrast and signal amplification. Live cell imaging suggested that the mannose-tagged fluorogen was transported to the lysosomes.
分子能够通过光实现荧光开启，因此在时空标记、表面图案化、监测细胞和分子事件以及高分辨率荧光成像方面受到了广泛关注。在这项工作中，我们报告了一种基于光引发的叠氮化物分子内 C-H 插入到相邻芳环中的荧光开启体系。通过全氟芳基叠氮化物与咔唑的级联亲核芳香取代反应，高效合成了被叠氮化物掩蔽的荧光团。该支架还允许与生物配体进行衍生化，本研究中以 d-甘露糖为例。这种光引发的分子内转化导致高收率、高光转化效率以及光激活和荧光激发的波长得到很好的分离。甘露糖衍生结构实现了时空激活，并表现出高对比度和信号放大。活细胞成像表明，甘露糖标记的荧光团被转运到溶酶体中。
