In this article we report the first example of a heterogeneous photolatent catalyst for the copper‐catalyzed azide‐alkyne cycloaddition (CuAAC) that is supported on chitosan. The heterogeneous copper(II) precatalyst was easily prepared by reaction of [Cu^II₂(3‐benzoylbenzoate)₄(H₂O)₂] complex 1 with chitosan powder. UV‐vis and EPR spectroscopy studies demonstrated that the Cu(II) ions are effectively photoreduced by low‐intensity UVAs. In particular, it was shown that the benzophenone photosensitizer, could be employed in catalytic amount, i. e. 10 mol% with respect to the Cu²⁺ ions, to effectively promote the Cu(II) to Cu(I) photoreduction process. A range of triazoles, in particular those bearing sugar moieties, could be effectively synthesized under light illumination and sodium ascorbate‐free conditions. ICP analysis did not show copper contamination of the final product, thereby evidencing tight incorporation of copper on the chitosan powder. Owing to its heterogeneous nature, the catalyst could be recovered and reused several times with no appreciable decrease in the catalytic activity. As a practical application of the procedure, the anticonvulsant drug rufinamide was isolated in 82% yield on a 10 mmol scale synthesis.

中文翻译：

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壳聚糖上铜（II）上的光氧化还原催化：在光潜伏CuAAC中的应用

在本文中，我们报告了壳聚糖负载的铜催化的叠氮化物-炔烃环加成反应（CuAAC）的非均相光潜催化剂的第一个示例。通过使[Cu ^II ₂（3-苯甲酰基苯甲酸酯）₄（H ₂ O）₂ ]配合物1与壳聚糖粉末反应，可以轻松制备多相铜（II）预催化剂。UV-vis和EPR光谱研究表明，低强度UVA可有效地将Cu（II）离子光还原。特别地，已表明二苯甲酮光敏剂可以催化量使用，即1。e。相对于Cu ²⁺为10摩尔％离子，以有效地促进Cu（II）到Cu（I）的光还原过程。可以在光照和无抗坏血酸钠的条件下有效地合成一系列三唑，尤其是那些带有糖部分的三唑。ICP分析没有显示出最终产品中的铜污染，从而证明了壳聚糖粉末上铜的紧密结合。由于其非均相性质，催化剂可以被回收并重复使用几次，而催化活性没有明显降低。该方法的实际应用是在10 mmol规模的合成中以82％的收率分离出抗惊厥药rufinamide。