Dual ligand-enabled iron and halogen-containing carboxylate-based photocatalysis for chloro/fluoro-polyhaloalkylation of alkenes.

Herein, we demonstrate a practical dual ligand-enabled iron photocatalysis paradigm-converting all kinds of halogen-containing carboxylates (C X COO, X: F, Cl, Br) into C X radicals for the valuable chloro/fluoro-polyhaloalkylation of non-activated alkenes with easily available trichloroacetonitrile/Selectfluor as the electrophilic halogenation reagent. The modular assembly of the effective iron and C X COO-based light-harvesting species using the two ligands-OMe/CF-substituted bipyridine and acetonitrile/trichloroacetonitrile is evidenced by detailed mechanistic studies. The late-stage modification, low loading amount of iron (TON: 257) and feasible gram-scale synthesis show the utility of this protocol. We thus anticipate that the dual ligand-enabled iron photocatalysis paradigm may facilitate activation and transformation of inert bulk chemicals.