Direct Observation of a Nonheme Iron(IV)–Oxo Complex That Mediates Aromatic C–F Hydroxylation

• Published in: Journal of the American Chemical Society 2014-10, Vol.136 (39), p.13542-13545
• Main Authors: Sahu, Sumit, Quesne, Matthew G, Davies, Casey G, Dürr, Maximilian, Ivanović-Burmazović, Ivana, Siegler, Maxime A, Jameson, Guy N. L, de Visser, Sam P, Goldberg, David P
• Format: Article
• Language: English
• Subjects: Aromatic compounds; Communication; Computation; Hydrocarbons, Fluorinated - chemical synthesis; Hydrocarbons, Fluorinated - chemistry; Hydroxylation; Iron; Iron Compounds - chemical synthesis; Iron Compounds - chemistry; Ligands; Models, Molecular; Molecular Conformation; Orientation; Synthesis; Trapping
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja507346t

The synthesis of a pentadentate ligand with strategically designed fluorinated arene groups in the second coordination sphere of a nonheme iron center is reported. The oxidatively resistant fluorine substituents allow for the trapping and characterization of an FeIV(O) complex at −20 °C. Upon warming of the FeIV(O) complex, an unprecedented arene C–F hydroxylation reaction occurs. Computational studies support the finding that substrate orientation is a critical factor in the observed reactivity. This work not only gives rare direct evidence for the participation of an FeIV(O) species in arene hydroxylation but also provides the first example of a high-valent iron–oxo complex that mediates aromatic C–F hydroxylation.