109276-62-2Relevant academic research and scientific papers
One-electron Oxidation of Closed-shell Molecules. Part 4. Acid-induced Oxidative Cleavage of Substituted 1,2,2,2-Tetraphenylethanones (Benzpinacolones) with Diaroyl Peroxides
Kitagawa, Toshikazu,Takeuchi, Ken'ichi,Murai, Osamu,Matsui, Shin,Inoue, Takeshi,Nishimura, Makoto et al.
, p. 1987 - 1996 (2007/10/02)
The acid-induced oxidative cleavage of anispinacolone with diaroyl peroxides in 1,2-dichloroethane-trifluoroacetic acid (TFA) has been investigated.The principal two products after work-up are tris-(p-methoxyphenyl)methanol and p-methoxybenzoic acid; the latter was found as anhydrides in the reaction mixture.Free-radical formation in the course of the cleavage was verified by polymerization of added acrylonitrile in the oxidation by bis-(3,5-dinitrobenzoyl) peroxide.When the oxidation of anispinacolone (90percent (13)C) by dibenzoyl peroxide was carried out in a (13)C n.m.r. probe, an emission peak, assigned to p-methoxybenzoic trifluoroacetic anhydride, was observed.The logarithms of the rate constants for oxidation of p-substituted benzpinacolones by dibenzoyl peroxide were linearly correlated with the oxidation potentials of the benzpinacolones.These results are consistent with a single-electron transfer (s.e.t.) pathway from benzpinacolones to dibenzoyl peroxide.The oxidation is first-order in each reactant and is promoted by TFA.The effect of TFA is accounted for by two factors, (i) assisted O-O bond cleavage of the peroxide radical anion by TFA, and (ii) the formation of protonated peroxide, a more powerful oxidizing species.The former factor is dominant at lower TFA concentrations ( 0.05 M), the latter at higher concentrations.
