An iridium photocatalyst and visible light facilitate a room temperature, nickel-catalyzed coupling of (hetero)aryl bromides with activated α-heterosubstituted or benzylic C(sp3)–H bonds. Mechanistic investigations on this unprecedented transformation have uncovered the possibility of an unexpected mechanism hypothesized to involve a Ni–Br homolysis event from an excited-state nickel complex. The resultant
铱光催化剂和可见光促进了(杂)芳基
溴化物与活化的α-杂取代或苄基C(sp3)-H键的室温
镍催化偶联。对这种前所未有的转变的机理研究揭示了一种意外机制的可能性,该机制假设涉及来自激发态
镍配合物的 Ni-Br 均裂事件。所得
溴自由基被认为会提取弱 C(sp3)-H 键以生成可参与 Ni 催化芳基化的反应性烷基自由基。有证据表明,
铱光催化剂通过三重态-三重态能量转移促进
镍激发和
溴自由基的产生。