关键词: 配体辅助, 电荷转移驱动, 光促, 铁催化, 自由基反应

Iron is the second most abundant metal in the earth's crust and possesses excellent biocompatibility, making the development of iron photocatalysis highly desirable for green and sustainable chemistry. In recent years, photoinduced iron catalysis driven by ligand-to-metal charge transfer (LMCT) has witnessed significant progress. This strategy involves the photoexcitation of iron-substrate (or reagent) complexes to induce intramolecular electron transfer, generating highly reactive radical species that trigger diverse organic transformations under mild conditions. This review systematically summarizes recent advances in ligand-facilitated LMCT-driven photoinduced iron catalysis. The discussions are categorized based on the types of substrates (or reagents) involved in the LMCT process, covering systems such as alkyl carboxylic acids, oxamic acids, fluorinated alkyl carboxylic acids, aryl carboxylic acids, alcohols, water, azides, and chlorides. Special emphasis is placed on the critical role of ligands (e.g., picolinic acids, polypyridyl amines) in tuning the redox properties of the iron center, prolonging excited-state lifetimes, and enhancing visible light absorption. The reaction mechanisms and synthetic applications are also discussed. Finally, the challenges and future prospects of this emerging field are highlighted.

Key words: ligand-facilitated, LMCT-driven, photoinduced, iron catalysis, radical reaction