90-44-8Relevant articles and documents
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Bansho,Nukada
, p. 579 (1960)
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ON THE MECHANISM OF THE CATHODIC REDUCTION OF ANTHRAQUINONE TO ANTHRONE.
Beck,Heydecke
, p. 37 - 43 (1987)
The cathodic reduction of anthraquinone in 85% H//2SO//4 at cathodes of glassy carbon or mercury has been investigated. Voltammetric curves exhibit two steps at plus 0. 23 and plus 0. 10 V vs. SHE. The limiting current densities show a ratio between 4:0 via 1:1 to 1:3, depending on the experimental conditions. Experiments at the RRDE indicate two reoxidizable intermediates. We derive a mechanism from our findings, involving the electrochemical formation of these intermediates, anthrasemiquinone AQH multiplied by (times) and anthrahydroquinone AQH//2. Both are subject to a bimolecular follow up reaction (disproportionation) to yield AQH//2 and anthrone. The rate constants are estimated to be 2. 10**3 and 3. 10**4 1 mol** minus **1 s** minus **1, respectively. Anthrone is the only reduction product which could be isolated.
A Synthetic Model for the Possible FeIV2(μ-O)2Core of Methane Monooxygenase Intermediate Q Derived from a Structurally Characterized FeIIIFeIV(μ-O)2Complex
Aono, Yuri,Harada, Masafumi,Kajiwara, Atsushi,Katano, Hajime,Kobayashi, Yoshio,Kodera, Masahito,Kotegawa, Fukue,Kubo, Minoru,Matsumoto, Arimasa,Mikata, Yuji,Nakayama, Hiromi,Yamamoto, Chihiro,Yanagisawa, Sachiko
supporting information, (2021/12/09)
A bis(μ-oxo)diiron(IV,IV) complex as a model for intermediate Q in the methane monooxygenase reaction cycle has been prepared. The precursor complex with a [FeIIIFeIV(μ-O)2] core was fully characterized by X-ray crystallography and other spectroscopic analyses and was converted to the [FeIV2(μ-O)2] complex via electrochemical oxidation at 1000 mV (vs Ag/Ag+) in acetone at 193 K. The UV-vis spectral features, M?ssbauer parameters (ΔEQ = 2.079 mm/s and δ= -0.027 mm/s), and EXAFS analysis (Fe-O/N = 1.73/1.96 ? and Fe···Fe = 2.76 ?) support the structure of the low-spin (S = 1, for each Fe) [FeIV2(μ-O)2] core. The rate constants of the hydrogen abstraction reaction from 9,10-dihydroanthracene at 243 K suggest the high reactivity of these synthetic bis(μ-oxo)diiron complexes supported by simple N4 tripodal ligand.
Insight into the chemoselective aromatic: Vs. side-chain hydroxylation of alkylaromatics with H2O2catalyzed by a non-heme imine-based iron complex
Ticconi, Barbara,Capocasa, Giorgio,Cerrato, Andrea,Di Stefano, Stefano,Lapi, Andrea,Marincioni, Beatrice,Olivo, Giorgio,Lanzalunga, Osvaldo
, p. 171 - 178 (2021/01/28)
The oxidation of a series of alkylaromatic compounds with H2O2 catalyzed by an imine-based non-heme iron complex prepared in situ by reaction of 2-picolylaldehyde, 2-picolylamine, and Fe(OTf)2 in a 2?:?2?:?1 ratio leads to a marked chemoselectivity for aromatic ring hydroxylation over side-chain oxidation. This selectivity is herein investigated in detail. Side-chain/ring oxygenated product ratio was found to increase upon decreasing the bond dissociation energy (BDE) of the benzylic C-H bond in line with expectation. Evidence for competitive reactions leading either to aromatic hydroxylation via electrophilic aromatic substitution or side-chain oxidation via benzylic hydrogen atom abstraction, promoted by a metal-based oxidant, has been provided by kinetic isotope effect analysis. This journal is
V2O5@TiO2 Catalyzed Green and Selective Oxidation of Alcohols, Alkylbenzenes and Styrenes to Carbonyls
Upadhyay, Rahul,Kumar, Shashi,Maurya, Sushil K.
, p. 3594 - 3600 (2021/07/02)
The versatile application of different functional groups such as alcohols (1° and 2°), alkyl arenes, and (aryl)olefins to construct carbon-oxygen bond via oxidation is an area of intense research. Here, we report a reusable heterogeneous V2O5@TiO2 catalyzed selective oxidation of various functionalities utilizing different mild and eco-compatible oxidants under greener reaction conditions. The method was successfully applied for the alcohol oxidation, oxidative scission of styrenes, and benzylic C?H oxidation to their corresponding aldehydes and ketones. The utilization of mild and eco-friendly oxidizing reagents such as K2S2O8, H2O2 (30 % aq.), TBHP (70 % aq.), broad substrate scope, gram-scale synthesis, and catalyst recyclability are notable features of the developed protocol.