Aryl amination is an essential transformation for medicinal, process, and materials chemistry. In addition to classic Buchwald–Hartwig amination conditions, blue-light-driven metallaphotoredox catalysis has emerged as a valuable tool for C–N cross-coupling. However, blue light suffers from low penetration through reaction media, limiting its scalability for industrial purposes. In addition, blue light enhances unwanted side-product formation in metallaphotoredox catalysis, namely hydrodehalogenation. Low-energy light, such as deep red (DR) or near-infrared (NIR), offers a solution to this problem as it can provide enhanced penetration through reaction media as compared to higher-energy wavelengths. Herein, we show that low-energy light can also enhance the desired reactivity in metallaphotoredox catalysis by suppressing unwanted hydrodehalogenation. We hypothesize that the reduced side product is formed by direct photolysis of the aryl–nickel bond by the high-energy light, leading to the generation of aryl radicals. Using deep-red or near-infrared light and an osmium photocatalyst, we demonstrate an enhanced scope of (hetero)aryl bromides and amine-based nucleophiles with minimal formation of hydrodehalogenation byproducts.

中文翻译：

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克服金属光氧化还原催化中的光化学限制：红光驱动的 C-N 交叉偶联

芳基胺化是医药、工艺和材料化学的重要转变。除了经典的 Buchwald-Hartwig 胺化条件外，蓝光驱动的金属光氧化还原催化已成为 C-N 交叉偶联的重要工具。然而，蓝光对反应介质的渗透率低，限制了其在工业用途上的可扩展性。此外，蓝光会促进金属光氧化还原催化（即加氢脱卤）中不需要的副产物形成。低能量光，例如深红光 (DR) 或近红外光 (NIR)，提供了解决此问题的方法，因为与高能量波长相比，它可以增强通过反应介质的穿透力。在此处，我们表明，低能光还可以通过抑制不需要的加氢脱卤来增强金属光氧化还原催化中所需的反应性。我们假设减少的副产物是由高能光直接光解芳基镍键形成的，导致芳基自由基的产生。使用深红色或近红外光和锇光催化剂，我们证明了（杂）芳基溴化物和胺基亲核试剂的范围扩大，加氢脱卤副产物的形成最少。