28047-94-1Relevant articles and documents
Catalytic performance of ceria nanorods in liquid-phase oxidations of hydrocarbons with tert-butyl hydroperoxide
Macedo, Andreia G.,Fernandes, Silvia E. M.,Valente, Anabela A.,Ferreira, Rute. A. S.,Carlos, Luis D.,Rocha, Joao
, p. 747 - 765 (2010)
The CeO2 nanorods (CeNR) promote the oxidation of ethylbenzene (PhEt) and cyclohexene with t-BuOOH, at temperatures as low as 55 °C. For both substrates the saturated C-H bonds are preferentially activated over the unsaturated ones. The catalyst seems fairly stable towards leaching phenomena. The liquid-phase oxidation catalysis may be associated with the Ce 3+/Ce4+ inter-conversion in the one-electron redox processes mediating the formation of tert-butyl-(per)oxy radicals. CeNR is very effective in H2O2 disproportionation. Pre-treatment of CeNR with H2O2 or t-BuOOH prior to the catalytic reaction enhances the reaction rate of PhEt with t-BuOOH in comparison to CeNR. Textural characterization and spectroscopic studies suggest that catalytic activation is associated to defect sites.
Green Organic Solvent-Free Oxidation of Alkylarenes with tert-Butyl Hydroperoxide Catalyzed by Water-Soluble Copper Complex
Ajjou, Abdelaziz Nait,Rahman, Ateeq
, p. 165 - 174 (2020/04/15)
Different benzylic compounds were efficiently oxidized to the corresponding ketones with aqueous 70% tert-butyl hydroperoxide (TBHP) and the catalytic system composed of CuCl2.2H2O and 2,2'-biquinoline-4,4'-dicarboxylic acid dipotassium salt (BQC). The catalytic system CuCl2/BQC/TBHP allows obtaining high yields at room temperature under organic solvent-free conditions. The interest of this system lies in its cost effectiveness and its benign nature towards the environment. Benzylic tertbutylperoxy ethers and benzylic alcohols were observed and suggested as the reaction intermediates. Analysis of organic products by atomic absorption did not show any contamination with copper metal. In terms of efficiency, CuCl2/BQC system is comparable or superior to the most of the catalytic systems described in the literature and which are based on toxic organic solvent.
Selective Oxidation of Benzylic C-H Bonds Catalyzed by Cu(II)/{PMo12}
Li, Peihe,Wang, Yingying,Wang, Xia,Wang, Yin,Liu, Ying,Huang, Keke,Hu, Jing,Duan, Limei,Hu, Changwen,Liu, Jinghai
, p. 3101 - 3109 (2020/03/23)
Precise catalytic regulation of carbon radical generation by a highly active oxygen radical to abstract the H atom in a C-H bond is an effective method for the selective activation of C-H synthetic chemistry. Herein, we report a facile catalyst system with commercially available copper(II)/{PMo12} to form a tert-butanol radical intermediate for the selective oxidation of benzylic C-H bonds. The reaction shows a broad range of substrates (benzyl methylene, benzyl alcohols) with good functional group tolerance and chemical selectivity. The corresponding carbonyl compounds were synthesized with good yields under mild conditions. DFT calculations and experimental analysis further demonstrated a reasonable carbon radical mechanism for this type of organic transformation reaction.
N-Doped carbon nanofibers derived from bacterial cellulose as an excellent metal-free catalyst for selective oxidation of arylalkanes
Huang, Runkun,Cao, Changyan,Liu, Jian,Sun, Dongping,Song, Weiguo
supporting information, p. 1935 - 1938 (2019/05/02)
N-Doped carbon nanofibers derived from one-step pyrolysis of low-cost bacterial cellulose with the assistance of urea were reported. Owing to their interconnected nanofibrous structure and high specific surface area as well as high N doping, they exhibited excellent catalytic performance for selective oxidation of arylalkanes even with O2 as an oxidant in aqueous solution.
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.
Catalytic selective oxidation of alkyl arenes to aryl tert. butyl peroxides with TBHP over Ru-exchanged Montmorillonite K10
Nikalje, Milind D.,Sudalai
, p. 5903 - 5908 (2007/10/03)
A mild and efficient catalytic method for the benzylic oxidation of alkyl arenes to the corresponding tert. butyl aryl peroxides is described using a catalytic amount of reusable solid, Ru(III)-exchanged Montmorillonite K10 and 70% tert. butyl hydroperoxide (TBHP) as oxidant.
Copper-catalyzed homolytic and heterolytic benzylic and allylic oxidation using tert-butyl hydroperoxide
Rothenberg, Gadi,Feldberg, Liron,Wiener, Harold,Sasson, Yoel
, p. 2429 - 2434 (2007/10/03)
Allylic and benzylic alcohols were oxidized in good yields to the respective ketones by tert-butyl hydroperoxide (TBHP) in the presence of copper salts under phase-transfer catalysis conditions. This dehydrogenation was found to proceed via a heterolytic mechanism. CuCl2, CuCl, and even copper powder were equally facile as catalysts, as they were all transformed in situ to Cu(OH)Cl which was extracted into the organic phase by the phase-transfer catalyst (PTC). Deuterium labeling experiments evidenced the scission of the benzylic C-H bond in the rate-determining step. Nonproductive TBHP decomposition was not observed in the presence of the alcohol substrates. Conversely, the oxygenation of π-activated methylene groups in the same medium was found to be a free radical process, and the major products were the appropriate tert-butyl peroxides. Catalyst deactivation, solvent effects, and extraction effects are discussed. By applying Minisci's postulations concerning the relative reactivity of TBHP molecules towards tert-butoxyl radicals in protic and nonprotic environments, the coexistence of the homolytic and the heterolytic pathways can be explained. A complete reaction mechanism is proposed, wherein the free-radical oxidation obeys Kochi's mechanism, and the heterolytic dehydrogenation is based on either a high-valent CuIV=O species or a [Cu(OH)Cl]2 species.
Vanadium-substituted MCM-41 zeolites as catalysts for oxidation of alkanes with peroxides
Neumann, Ronny,Khenkin, Alexander M.
, p. 2643 - 2644 (2007/10/03)
Alkanes are oxidized selectively to ketones using V-MCM-41 with isobutyraldehyde/dioxygen as the preferred oxidant in terms of product selectivity and catalyst stability and recycle.
New Syntheses of Mixed Peroxides under Gif-Barton Oxidation of Alkylbenzenes, Conjugated Alkenes and Alkanes; a Free-radical Mechanism
Minisci, Francesco,Fontana, Francesca,Araneo, Silvia,Recupero, Francesco
, p. 1823 - 1824 (2007/10/02)
Syntheses of mixed peroxides are performed under Gif oxidation of alkylaromatics, electron-rich conjugated alkenes (styrene, α-methylstyrene) or cyclohexane and acrylonitrile; chemical and kinetic evidence support a free-radical redox chain mechanism.
Cobalt(III) Alkylperoxy Complexes. Synthesis, X-ray Structure, and Role in the Catalytic Decomposition of Alkyl Hydroperoxides and in the Hydroxylation of Hydrocarbons.
Saussine, Lucien,Brazi, Eric,Robine, Alain,Mimoun, Hubert,Fischer, Jean,Weiss, Raymond
, p. 3534 - 3540 (2007/10/02)
Novel cobalt(III) alkylperoxy complexes with the general formula Co(R''BPI)(OCOR')(OOR) and Co(BPB)(OOt-Bu)(4-Mepy) were synthesized from the reaction of alkyl hydroperoxides with their Co(II) precusor, and characterized by physicochemical methods.The X-ray structure of Ib (R'' = H, R' = Ph, R = t-Bu) revealed a distorted octahedral environment with a chelating carboxylate moiety and an apically bonded tert-butylperoxy group.The reactivity of cobalt(III) alkylperoxy complexes toward hydrocarbons was found to be dependent on their thermal decomposition rate, with type I complexes being the most reactive ones.Saturated hydrocarbons are oxidized by Co(III) tert-butylperoxy complexes into alcohols, ketones, and tert-butylperoxy products.The hydroxylation reaction preferentally occurs at the more nucleophilic C-H bonds with extensive epimerization at the hydroxylated carbon atom.Hydrocarbons having labile allylic or benzylic C-H bonds react beginning at room temperature to give a large amount of allylic or benzylic tert-butyl peroxide.Olefins having no allylic hydrogen atom are preferentially transformed into epoxides.The catalytic hydroxylation of alkanes by t-BuOOH in the presence of complexes I-III has the same characteristics as the stoichiometric reaction.The homolytic decomposition and reactivity of cobalt(III) alkylperoxy complexes is discussed in the context of the Haber-Weiss mechanism of alkyl hydroperoxide decomposition and of hydrocarbon hydroxylation by first-row transition-metal peroxides.
