Porphyrin, polyhalogenated

Buschmann, J., W. Angst, and R. P. Schwarzenbach, Iron porphyrin and cysteine mediated reduction of ten polyhalogenated methanes in homogeneous aqueous solution Product analyses and mechanistic considerations , Environ. Sci. Technol., 33, 1015-1020 (1999). 

In order to explain their high activity and stability it was postulated that polyhalogenation of the porphyrin ring system not only stabilizes the latter towards oxidative destruction but also stabilizes the oxoiron intermediate with respect to p-oxo dimer formation. In principle, it should also be possible to design stable solid catalysts capable of mediating analogous selective oxidations in the liquid phase. 

Figure 9 Formulas of polyhalogenated porphyrins used in model systems for cytochrome P450...

HillRHJr. 1985. Effects of polyhalogenated aromatic compounds on porphyrin metabolism. Environ... 

A very promising system for hydrocarbon oxygenation with 2,6-dichloropyridine AAoxide in the presence of electron-deficient, polyhalogenated ruthenium porphyrins has been reported ... 

T. Carofiglio (1997). Rapid catalytic oxygenation of hydrocarbons with polyhalogenated ruthenium porphyrin complexes. Stud. Surf. Sci. Catal. 110, 865-872. 

Mansuy, D. and J.-P. Battioni (1982). Isolation of sigma-alkyl-iron(Ill) or carbene-iron(II) complexes from reduction of polyhalogenated compounds by iron(Il)-porphyrins The particular case of halothane CFjCHClBr. J. Chem. Soc. Chem. Commun. 638-639. 

Polyhalogenated methanes and ethanes are also reduced in both H2S (1 mM)/ juglone (200 jlM) and the iron porphyrin (2-50 piM) cysteine (5 mM) systems. " The reduction for some alkyl halides in the presence of the iron porphin is indicated by a second-order rate constant, since the rate is proportional to the concentration of both the alkyl halide and the porphyrin (Table 7.9). A half-life at a concentration of 10 pM iron porphyrin is included. 

Carbene intermediates have also been identified as products of the reduction of polyhalogenated methanes by iron porphyrins in the presence of cysteine [119]. Such a process seems to be of particular interest because of its potential applicability in the treatment of wastes as well as in remediation approaches to removing polyhalogenated methanes from contaminated soils. 

Carrier, M.N., C. Scheer, P. Gouvine, J.F. Bartoli, P. Battioni, and D. Mansuy (1990). Biomimehc hydroxylation of aromatic compounds Hydrogen peroxide and manganese-polyhalogenated porphyrins as a particularly good. Tetrahedron Lett. 31, 6645-6648. 

Both polymeric polyhalogenated iron porphyrins [338] and polyhalogenated metalloporphyrins covalently bound to polymeric supports [339] have been shown to be efficient catalysts for hydroxylation and epoxidation, consistent with the results reviewed in 6.12.1. 

---