Oxygenated Fenton chemistry

McFaul PA, Wayner DDA, Ingold KU (1998) A radical account of oxygenated Fenton chemistry". Acc Chem Res 31 159-162... 

Sawyer DT, Sobkowiak A, Matsushita T (1996) Metal [MLX M = Fe, Cu, Co, Mn]/hydroperoxide-in-duced activation of dioxygen for the oxygenation of hydrocarbons oxygenated Fenton chemistry. Acc Chem Res 29 409-416... 

Scheme X.6. The mechanism proposed for the ketonization of alkanes, RJl, catalyzed by iron complexes ( oxygenated Fenton chemistry ).

This phenomenon has been termed oxygenated Fenton chemistry. It has also been observed with [Co (bpy)2 ] in 4 1 MeCN/py, which effects ketonization of the methylenic centers of cyclohexane, cyclohexene and... 

Biaglow JE, Kachur AV (1997) The generation of hydroxyl radicals in the reaction of molecular oxygen with polyphosphate complexes of ferrous ion. Radiat Res 148 181-187 Biaglow JE, Field KD, Manevich Y, Tuttle S, Kachur A, Uckun F (1996) Role of guanosine triphosphate in ferric ion-linked Fenton chemistry. Radiat Res 145 554-562 Bielski BHJ (1991) Studies of hypervalent iron. Free Radical Res Commun 12/13 469-477 Bielski BHJ, Allen AO, Schwarz HA (1981) Mechanism of disproportionation of ascorbate radicals. J Am Chem Soc 103 3516-3518... 

During the ferroxidation reaction, a blue color with an absorption maximum of 650 run appears. This persists in oxygen-limited conditions and decays as iron oxidation proceeds. " In frog H-chain ferritin, resonance Raman studies indicate a similar absorption is associated with an Fe(III)-tyrosinate. Harrison and Treffty have considered these and other studies and attribute the transient color to formation of a /x-l,2-peroxodiferric intermediate, which decays to a more stable /x-oxodiferric species as occurs in methane monooxygenase, ribonucleotide reductase, and model compounds. Protein radicals distinct from reactive oxygen species have been observed that have been attributed to damage caused by Fenton chemistry. ... 

Reaction (16) is a Fenton-type reaction (Fenton, 1894 Croft et al., 1992). There is still controversy as to whether the reaction of Cu+ and H2O2 leads to the formation of (HO) or even a Cu + species (Bielski and Cabelli, 1991). As for iron-catalysed reactions, Fenton chemistry probably involves (oxygen)iron(2-i-) [FeO] + intermediates, which are strong oxidants as well. The reaction of Fe +(chelate) -1- H2O2 could yield (O2), but is reported to be rather slow (Halliwell and Gutteridge, 1989, 1992 Chiueh et al., 1992). In vivo formation of (HO) is determined by measurement of hy-droxylated salicylic acid (Van Steveninck et al.,... 

There are also other avenues by which -NO may serve a protective role in ischemia-reperfusion phenomena. Under these circumstances, known to include a high rate of production of oxygen free radicals, -NO can react with Oi to divert Oi through ONOO -dependent (and potentially less damaging) oxidative and decomposition pathways. Nitric oxide may also confer protection by reacting with iron to form iron-nitrosyl compounds. By binding free coordination sites of iron, -NO can limit Fenton chemistry and iron-dependent electron transfer reactions (Kanner etal., 1991 Ignarro,... 

In polluted air, the main fate of aqueous H2O2 is the fast oxidation of dissolved SO2 (Chapter 5.5.2.2), which limits the lifetime of both species. In biological systems, besides inorganic Fenton chemistry, three oxygenic base processes occur (Haber and Willstatter 1931) ... 

---