Rapid Iron(III)−Fluoride‐Mediated Hydrogen Atom Transfer
Chakadola Panda, Lorna M. Doyle, Robert Gericke, Aidan R. McDonald
Abstract
Abstract We anticipate high‐valent metal–fluoride species will be highly effective hydrogen atom transfer (HAT) oxidants because of the magnitude of the H−F bond (in the product) that drives HAT oxidation. We prepared a dimeric Fe III (F)−F−Fe III (F) complex ( 1 ) by reacting [Fe II (NCCH 3 ) 2 (TPA)](ClO 4 ) 2 (TPA=tris(2‐pyridylmethyl)amine) with difluoro(phenyl)‐λ 3 ‐iodane (difluoroiodobenzene). 1 was a sluggish oxidant, however, it was readily activated by reaction with Lewis or Brønsted acids to yield a monomeric [Fe III (TPA)(F)(X)] + complex ( 2 ) where X=F/OTf. 1 and 2 were characterized using NMR, EPR, UV/Vis, and FT‐IR spectroscopies and mass spectrometry. 2 was a remarkably reactive Fe III reagent for oxidative C−H activation, demonstrating reaction rates for hydrocarbon HAT comparable to the most reactive Fe III and Fe IV oxidants.