Detection of Alkylperoxo and Ferryl, (Fe(IV)=O)(2+), Intermediates during the Reaction of tert-Butyl Hydroperoxide with Iron Porphyrins in Toluene Solution

Article abstract of DOI:10.1021/ja00202a021

PFe^II and PFe^IIIOH (P is a porphyrin dianion) catalyze the decomposition of tert-butyl hydroperoxide in toluene solution without appreciable attack on the porphyrin ligand. (1)H NMR spectroscopic studies at low temperature (-70 deg C) give evidence for the formation of a high-spin, five-coordinate intermediate, PFe^IIIOOC(CH3)3.On warming this decomposes to PFe^IIIOH (P = tetramesitylporphyrin, TMP) or PFe^IIIOFe^IIIP (P = tetra-p-tolylporphyrin, TTP) with the formation of (TMP)Fe^IV=O as an observed intermediate in the first case.Treatment of PFe^IIIOOC(CH3)3 at -70 deg C with N-methylimidazole (MeIm) yields the intermediate (MeIm)PFe^IV=O.Organic products formed from this reaction are tert-butyl alcohol, di-tert-butyl peroxide, benzaldehyde, acetone, and benzyl-tert-butyl peroxide, which arise largely from a radical chain process initiated by the iron porphyrin but continuing without its intervention.