C–H functionalization reactions constitute a key pillar in streamlining synthesis methods. In this context, the use of visible light to mediate metal-catalyzed C–H functionalization reactions is currently emerging as an important strategy to facilitate such transformations and enables mild C–H functionalization reactions at ambient conditions without the need for external photosensitizers or reactive reagents. Herein, we report on a photochemical approach that allows for C(sp³)–H functionalization reactions using simple [Ru(cymene)Cl₂]₂ and a phosphoric acid diester as catalysts. This strategy enables formal C(sp³)–C(sp³) coupling reactions to access valuable, sterically demanding amines and expands photochemical C–H functionalization reactions toward reaction pathways exclusive to photochemistry. Detailed mechanistic experiments and density functional theory calculations suggest the formation of a cyclometalated ruthenium complex that is stabilized by the phosphoric acid diester anion and serves as a catalyst for C–H functionalization reactions and single-electron transfer to access C–H functionalization reactions via a deprotonation-radical addition mechanism.

C-H 官能化反应是简化合成方法的关键支柱。在这种情况下，使用可见光来介导金属催化的 C-H 官能化反应目前正在成为促进此类转化的重要策略，并在环境条件下实现温和的 C-H 官能化反应，而无需外部光敏剂或反应试剂. 在此，我们报告了一种光化学方法，该方法允许使用简单的 [Ru(cymene)Cl ₂ ] ₂和磷酸二酯作为催化剂进行 C(sp ³ )–H 官能化反应。这种策略使正式的 C(sp ³ )–C(sp ³) 偶联反应以获取有价值的、空间要求高的胺，并将光化学 C-H 官能化反应扩展到光化学独有的反应途径。详细的机械实验和密度泛函理论计算表明，形成了一种由磷酸二酯阴离子稳定的环金属化钌配合物，并作为 C-H 官能化反应和单电子转移的催化剂，通过去质子化-自由基加成机制。