24456-96-0Relevant academic research and scientific papers
Organophotocatalytic Aerobic Oxygenation of Phenols in a Visible-Light Continuous-Flow Photoreactor
Wellauer, Jo?l,Miladinov, Dragan,Buchholz, Thomas,Schütz, Jan,Stemmler, René T.,Medlock, Jonathan A.,Bonrath, Werner,Sparr, Christof
supporting information, p. 9748 - 9752 (2021/05/27)
A mild photocatalytic phenol oxygenation enabled by a continuous-flow photoreactor using visible light and pressurized air is described herein. Products for wide-ranging applications, including the synthesis of vitamins, were obtained in high yields by precisely controlling principal process parameters. The reactor design permits low organophotocatalyst loadings to generate singlet oxygen. It is anticipated that the efficient aerobic phenol oxygenation to benzoquinones and p-quinols contributes to sustainable synthesis.
Oxidation of Electron-Rich Arenes Using HFIP-UHP System
Llopis, Natalia,Baeza, Alejandro
, p. 6159 - 6164 (2020/05/20)
The straightforward oxidation of electron-rich arenes, namely, phenols, naphthols, and anisole derivatives, under mild reaction conditions, is described by means of the use of an environmentally benign HFIP-UHP system. The corresponding quinones or hydroxylated arenes were obtained in moderate to good yields.
Synthesis of 2-substituted quinones, vitamin K3, and vitamin K1 from p-cresol. BF3·OEt2-catalyzed methyl migration of 4-tert-butyldioxycyclohexadienones
Murahashi, Shun-Ichi,Fujii, Akiko,Inubushi, Yasutaka,Komiya, Naruyoshi
scheme or table, p. 2339 - 2341 (2010/05/19)
BF3·OEt2-catalyzed methyl group migration of 4-methyl-4-tert-butyldioxycyclohexadienone, which is obtained by ruthenium-catalyzed oxidation of p-cresol with tert-butyl hydroperoxide, in hexafluoro-2-propanol/toluene gave toluquinone efficiently. The reaction can be applied to the regio-selective short-step syntheses of vitamin K3 and vitamin K1 from p-cresol.
Dimethyl carbonate: an environmentally friendly solvent for hydrogen peroxide (H2O2)/methyltrioxorhenium (CH3ReO3, MTO) catalytic oxidations
Bernini, Roberta,Mincione, Enrico,Barontini, Maurizio,Crisante, Fernanda,Fabrizi, Giancarlo,Gambacorta, Augusto
, p. 6895 - 6900 (2008/02/10)
Environmentally friendly oxidations of various organic compounds with the hydrogen peroxide (H2O2)/methyltrioxorhenium (CH3ReO3, MTO) catalytic system have been described in dimethyl carbonate (DMC), a cheap commercially available and benign chemical having interesting solvating properties, low toxicity and high biodegradability. Oxidations proceeded with good conversions and in good yields. Spectrophotometric analysis demonstrated that the [CH3ReO(O-O)2] complex was formed in DMC and that it was stable for several days at room temperature.
Convenient oxidation of alkylated phenols and methoxytoluenes to antifungal 1,4-benzoquinones with hydrogen peroxide (H2O2)/methyltrioxorhenium (CH3ReO3) catalytic system in neutral ionic liquid
Bernini, Roberta,Mincione, Enrico,Barontini, Maurizio,Fabrizi, Giancarlo,Pasqualetti, Marcella,Tempesta, Sabrina
, p. 7733 - 7737 (2007/10/03)
Alkylated phenol and methoxytoluene derivatives were catalytically and selectively oxidized to the corresponding 1,4-benzoquinones in good conversions and yields. Reactions were performed with hydrogen peroxide (H2O2)/methyltrioxorhenium (CH3ReO3) in 1-butyl-3-methylimidazolium tetrafluoroborate [bmim]BF4, a neutral ionic liquid. Compounds were tested in vitro for their antifungal activity against the growth of several widespread soil fungi. Some of them were proved to be potent inhibitors of Fusarium sp. than ketoconazole, a commercially available and expensive antifungal agent.
Reactivity and reaction pathways of alkylalkoxybenzene radical cations. Part 2. Effects of 2-alkyl substituents on the relative importance of deprotonation over de-tert-butylation of 2-alkyl-5-tert-butyl-1,4-dimethoxybenzene radical cations
Zhao, Cheng-Xue,Gong, Yue-Fa,He, Hai-Ying,Jiang, Xi-Kui
, p. 688 - 694 (2007/10/03)
The 2-alkyl-5-tert-butyl-1,4-dimethoxybenzene radical cations 1+·a-e (2-alkyl = Me, Et, i-Pr, c-PrCH2 and PhCH2) generated in one-electron oxidauon of their parent compounds 1a-e by pentafluorobenzoyl peroxide or cerium(IV) sulfate were characterized by EPR spectrometry. The product analysis shows that under certain conditions 1+·a-e may collapse through two competitive pathways, i.e. deprotonation and de-tert-butylation. The deprotonation of 1+·a-e is further assured by EPR observations of the corresponding benzyl radical intermediates. The relative importance of the two pathways is greatly dependent on the structure of the alkyl substituents, the nature of the solvents and the reaction temperature. For deprotonation, the reactivity order is found to be c-PrCH2 >Me >PhCH2 >Et ? i-Pr. Copyright
A New Selective Method for the Homolytic Alkylation and Carboxylation of Quinones by Monoesters of Oxalic Acid
Coppa, Fausta,Fontana, Francesca,Lazzarini, Edoardo,Minisci, Francesco
, p. 1299 - 1302 (2007/10/02)
Alkyl and alkoxycarbonyl radicals were generated by oxidative decarboxylation of oxalic acid monoesters by persulfate; they were then utilized for the selective substitution of quinones.
