2186-29-0Relevant academic research and scientific papers
Oxidizing properties of the tert-butyl hydroperoxide-tetra-tert- butoxychromium system
Stepovik,Potkina,Poddelskii
, p. 2005 - 2017 (2014/01/17)
tert-Butyl hydroperoxide reacts with the tetra-tert-butoxychromium by oxidizing the latter to chromyl CrV=O (C6H6, 20 C). At t-BuOOH-Cr(OBu-t)4 ratio of 2: 1 or higher, oxygen is released. The occuring processes include the formation of chromium-containing peroxides and peroxytrioxydes. The t-BuOOH-Cr(OBu-t)4 system oxidizes aromatic hydrocarbons of various structures (anthracene, 9,10-dimethylanthracene, 1,1-diphenylethylene, alkylarenes), as well as primary and secondary alcohols. Depending on the structure of the substrate, the oxidants are: in situ generated oxygen including that in the singlet state, peroxy radicals, or chromium-containing peroxides.
Selective one-pot synthesis of various phenols from diarylethanes
Nakamura, Ryota,Obora, Yasushi,Ishii, Yasutaka
supporting information; experimental part, p. 3417 - 3419 (2009/02/05)
Various substituted phenols were selectively synthesized by a one-pot reaction through the NHPI-catalyzed aerobic oxidation of 1,1-diarylethanes followed by treatment with dilute sulfuric acid. The Royal Society of Chemistry.
Oxygen activation on metallic centers and oxidizing abilities of such oxygen
Zaburdaeva, Elena A.,Dodonov, Viktor A.,Stepovik, Larisa P.
, p. 1265 - 1268 (2008/02/04)
It was shown that metallcontaining peroxides such as XOOOBu-t [X = (t-BuO)2Al, (t-BuO)3Ti] generate molecular oxygen in the electron-excited singlet state (1O2). These ozonides and η2-peroxocomplex Ph3Bi(η2O2) demonstrate high oxidative activity towards some classes of organic substances under mild conditions (20 °C).
Deuterium kinetic isotope effects in homogeneous decatungstate catalyzed photooxygenation of 1,1-diphenylethane and 9-methyl-9H-fluorene: Evidence for a hydrogen abstraction mechanism
Lykakis, Ioannis N.,Orfanopoulos, Michael
, p. 7835 - 7839 (2007/10/03)
The homogeneous decatungstate W10O324- catalyzed photooxygenation of 1,1-diphenylethane and 9-methyl-9H-fluorene has been studied mechanistically. The primary and β-secondary kinetic isotope effects provide strong evidence for a stepwise mechanism, with a hydrogen atom abstraction in the rate-determining step.
Titanium(IV) tert-butoxide-tert-butyl hydroperoxide system as oxidant for C-H bonds in hydrocarbons and oxygen-containing compounds
Stepovik,Gulenova,Martynova
, p. 507 - 513 (2007/10/03)
The system Ti(IV) tetra-tert-butoxide-tert-butyl hydroperoxide in mild conditions (20°C) oxidizes C-H bonds of methyl (toluene), methylene (hexane, ethylbenzene, benzyl ethyl ether), and methine (1, 1-diphenylethane, triphenylmethane) groups. The role of oxidant is played by the oxygen generated by the system. The process involves free radicals and produces hydroperoxides and Ti(IV) peroxides. The latter decompose both with preservation and decomposition of the hydrocarbon skeleton. 2005 Pleiades Publishing, Inc.
Characterization, via ESR Spectroscopy, of Radical Intermediates in the Photooxidation of Arylcarbinols by Ceric Ammonium Nitrate
Grossi, Loris,Strazzari, Samantha
, p. 2748 - 2754 (2007/10/03)
The photooxidation by ceric ammonium nitrate (CAN) of several aryl and naphthylcarbinols has been studied by means of ESR spectroscopy. For all the investigated arylcarbinols, but not for the naphthyl derivatives, it has been possible to detect radical intermediates deriving from the parent alkoxyl radicals. In particular, in the photooxidation of 1,1-diphenylethanol, a bridged-radical intermediate has been detected. The assignment has been validated through experiments with two different labeled compounds: the 1,1-[2′, 3′, 4′, 5′, 6′, 2″, 3″, 4″, 5″, 6″-2H10]diphenylethanol and the 1,1-diphenyl[2, 2, 2-2H3]ethanol. A similar bridged radical has been found to be formed in the photooxidation of triphenylmethanol, while, for the 1,1-diphenylpropanol, the only detectable species has been the ethyl radical deriving from a competitive β-scission process. Finally, for the 2-phenylpropan-2-ol (cumyl alcohol), two radical species have been identified: the methyl, deriving from the β-scission process, and the cyanomethylene, deriving from H-abstraction of the cumyloxyl radical from the solvent. A kinetic study on the competition of the two processes has also been conducted and the parameters of the Arrhenius equation for the latter process have been estimated.
Oxidation of Alkylarenes by the Aluminum Tri-tert-butoxide-tert-Butyl Hydroperoxide System
Stepovik,Dodonov,Zaburdaeva
, p. 111 - 115 (2007/10/03)
Oxidation of several alkylarenes containing primary, secondary, and tertiary radicals (cumene, 1,1-diphenylethane, triphenylmethane, and 1,1-diphenylpropane) by the aluminum tri-tert-butoxide-tert-butyl hydroperoxide system was studied. Oxidation of cumene, 1,1-diphenylethane, and triphenylmethane proceeds through the formation of tertiary hydroperoxides due to dimerization of hydroperoxy and carbon-centered radicals. Reaction of 1,1-diphenylpropane with the oxidation system occurs through the methylene group and is accompanied by cleavage of the carbon-carbon bond of alkylarene.
Absolute rate constants for hydrocarbon autoxidation. 32. On the self-reaction of 1,1-diphenylethylperoxyl in solution
Howard, J. A.,Chenier, J. H. B.,Yamada, T.
, p. 2566 - 2572 (2007/10/02)
The major products of the self-reaction of 1,1-diphenylethylperoxyl have been determined from product studies of the autoxidation of 1,1-diphenylethane, induced decomposition of 1,1-diphenylethyl hydroperoxide, and decomposition of 2,2,3,3-tetraphenylbutane under an atmosphere of oxygen.Overall self-reaction is a complex free-radical process involving the intermediacy of 1,1-diphenylethoxyl and 1-phenyl-1-phenoxyethoxyl which undergo H-atom abstraction, β-scission and, in the case of the former radical, rearrangement.Hydroperoxide decomposition under an atmosphere of (36)O2, has shown that 1,1-diphenylethylperoxyl undergoes β-scission faster than α-cumylperoxyl at 303 K in solution.The values of the rate constants for self-reaction of Ph2C(Me)O2. relative to those for the tert-butylperoxyl are, however, not affected by this reaction.Furthermore they are not affected to any appreciable extent by the efficiency with which Ph2C(Me)O. , formed in nonterminating self-reaction, escape from the solvent cage.They are influenced principally by the first-order rate of decomposition of Ph2C(Me)OOOOC(Me)Ph2.
Absolute rate constants for hydrocarbon autoxidation. 30. On the self-reaction of the α-cumylperoxy radical in solution
Howard, J. A.,Bennett, J. E.,Brunton, G.
, p. 2253 - 2260 (2007/10/02)
Although it is generally accepted that the self-reaction of cumylperoxy radicals is a second-order process, recent reports have cast doubt on the overall validity of this assumption.Therefore we have reinvestigated some aspects of the self-reaction to clarify the kinetic and mechanistic features.Our product studies are entirely consistent with the accepted mechanism for the self-reaction of cumylperoxy radicals and no evidence was obtained for competing reactions.Results obtained with 36O2 labelled materials confirm the previous conclusion that reversible scission of cumylperoxy radicals to give oxygen and cumyl radicals does not compete significantly with the self-reaction at ambient temperatures.Kinetic studies, under both steady-state and transient conditions, establish clearly that the self-reaction of cumylperoxy radicals is a second order process.A possible explanation is proposed to account for the previous observations which indicated that the self-reaction was a first order process.Further, we show that the changes observed in the esr spectrum of the cumylperoxy radicals, which were attributed to the formation of a complex with cumylhydroperoxyde, are caused by changes in the viscosity of the solution.
