Fluorescent active small compounds containing 5H-pyrido[2′,1:2,3]imidazo[4,5-b]indole core could be successfully synthesized by double CN coupling reaction from 3-iodo-2-(2-bromophenyl)imidazo[1,2-a]pyridine with different amines in high yields under air atmosphere. HKUST-1 was found to be the most suitable heterogeneous catalyst for this transformation. Interestingly, HKUST-1 catalyst (∼12 mol% Cu loading for each reaction) showed highly active, robust, and recyclable properties with the tolerance of broad substrate scope. Remarkably, the mechanism for the CN coupling reaction undergoing Cu¹⁺/ Cu³⁺ catalytic cycle was proposed from several observed important evidence. Cu²⁺ sites in the node of HKUST-1 structure could be reduced to Cu¹⁺ which initiated the formation of radical amine species. This method may give potential applications in the pharmaceutical and fine chemical industries.

3-碘-2-(2-溴苯基)双C -N偶联反应成功合成了以5H-吡啶并[2′,1:2,3]咪唑并[4,5- b ]吲哚为核心的荧光活性小分子化合物)咪唑并[1,2- a ]吡啶与不同的胺在空气气氛下高收率。HKUST-1 被发现是最适合这种转化的非均相催化剂。有趣的是，HKUST-1 催化剂（每个反应的 Cu 负载量约为 12 mol%）显示出高活性、稳健和可回收的特性，并且具有广泛的底物范围耐受性。值得注意的是，从几个观察到的重要证据中提出了经历Cu ¹⁺ / Cu ³⁺催化循环的C N 偶联反应的机理。铜HKUST-1结构节点中的^{2+位点可被还原为Cu 1+}，从而引发自由基胺类物质的形成。该方法可能在制药和精细化工行业具有潜在的应用价值。