Mechanistic insight into the aromatic hydroxylation by high-valent iron(IV)-oxo porphyrin pi-cation radical complexes.
Mechanistic studies of the aromatic hydroxylation by high-valent iron(IV)-oxo porphyrin pi-cation radicals revealed that the aromatic oxidation involves an initial electrophilic attack on the pi-system of the aromatic ring to produce a tetrahedral radical or cationic sigma-complex. The mechanism was proposed on the basis of experimental results such as a large negative Hammett rho value and an inverse kinetic isotope effect. By carrying out isotope labeling studies, the oxygen in oxygenated products was found to derive from the iron-oxo porphyrin intermediates.
Kang
Min-Jung
MJ
Department of Chemistry, Division of Nano Sciences, and Center for Biomimetic Systems, Ewha Womans University, Seoul 120-750, Korea.
Song
Woon Ju
WJ
Han
Ah-Rim
AR
Choi
Young S
YS
Jang
Ho G
HG
Nam
Wonwoo
W
D002412:Cations; D002625:Chemistry, Organic / Q000379:methods*; D007501:Iron / Q000737:chemistry*; D007700:Kinetics; D008956:Models, Chemical; D008968:Molecular Conformation; D011166:Porphyrins / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013997:Time Factors
D002412:Cations; D011166:Porphyrins; D007501:Iron