Copper coil flow reactors represent an economic, abundant, and durable platform for conducting copper-catalyzed reactions. These have been used in the past for Ullmann-type reactions starting from aryl iodides. However, no procedures have been described for the activation of less reactive aryl bromides. In this work, we successfully developed a method for the hydroxylation of aryl bromides promoted by a copper coil reactor. Notably, the presence of both a diamine ligand and DMF is key for the reaction to proceed. An inorganic base such as Na₂CO₃ also improved the reaction yield by minimizing the formation of side products. The setup has been applied to a range of disubstituted aryl bromides in moderate to good yields and was tested under 24 h of continuous operation, showing stable yields, thus proving the robustness of the catalysis. Finally, the lifetime of a copper reactor operating under the described conditions has been calculated for the first time, proving that this technology is safe to operate at an industrial scale.

中文翻译：

---

向 Ullmann 的工作致敬：将铜线圈反应器的应用扩展到芳基溴的羟基化反应


铜盘管流动反应器代表了进行铜催化反应的经济、丰富且耐用的平台。这些过去曾用于从芳基碘化物开始的 Ullmann 型反应。然而，尚未描述用于活化反应性较低的芳基溴的程序。在这项工作中，我们成功开发了一种由铜线圈反应器促进芳基溴羟基化的方法。值得注意的是，二胺配体和 DMF 的存在是反应进行的关键。Na₂CO₃ 等无机碱也通过最大限度地减少副产物的形成来提高反应产率。该设置已应用于一系列中等至良好的二取代芳基溴，并在连续运行 24 小时下进行了测试，显示出稳定的产量，从而证明了催化的稳健性。最后，首次计算了在所述条件下运行的铜反应器的寿命，证明该技术在工业规模下运行是安全的。