Mechanism‐Driven Bioactive Indazole Frameworks: Photoinitiated Demethylation–Aromatization Synthesis and Biosensing Applications

作者：Yifeng Ou, Songhua Chen, Qian Lei, Yang Shen, Niu Tang, Yongbo Zhou, Shuang‐Feng Yin, Nobuaki Kambe, Lin Yuan, Renhua Qiu · 发表于：Angewandte Chemie International Edition · 年份：2025 · DOI：10.1002/anie.202507163 · 被引用次数：4 · 研究领域：Photochromic and Fluorescence Chemistry、Sulfur-Based Synthesis Techniques、Synthesis of Indole Derivatives

Indazole frameworks are pivotal in medicinal chemistry and fluorescent conjugate design. Herein, we reported a photochemical strategy enabling efficient N-demethylation and aromatic cyclization of N-methyl amines via UV-induced nitroso intermediates, offering an environmentally benign route to structurally diverse 2H-indazole scaffolds. Diverging from conventional methods, this protocol demonstrates exceptional substrate compatibility with various alkyl/aryl amines, facilitating streamlined assembly of functionalized 2H-indazole modules. The methodology has been successfully applied to synthesize modified drugs and tumor-specific fluorescent probes targeting G-quadruplexes. Preliminary evaluations of physiological toxicity and cellular fluorescence imaging highlight their biomedical potential, establishing these strategies as potential tools for pharmacological development and bioimaging research.