2235-15-6Relevant articles and documents
Oxidation of alkyl aromatics to ketones by tert-butyl hydroperoxide on manganese dioxide catalyst
Burange, Anand S.,Kale, Sandip R.,Jayaram, Radha V.
, p. 2989 - 2992 (2012)
The catalytic activity of the manganese oxide was investigated for the oxidative functionalization of alkylaromatics to benzylic ketones using tert-butyl hydroperoxide (TBHP) as an oxidant. Manganese oxides of different types were tested for this reaction. Of all the oxides, the nano amorphous manganese dioxide exhibited significant catalytic activity and selectivity for the reaction. The nano amorphous MnO2/TBHP catalytic system could also be reused for six consecutive cycles with no considerable loss in catalytic activity.
The electron as a protecting group. 3. Generation of acenaphthyne radical anion and the determination of the heat of formation of a strained cycloalkyne
Broadus,Kass
, p. 4189 - 4196 (2001)
Acenaphthyne dicarboxylate (12) was transferred into the gas phase from solution via electrospray ionization and subsequently was sequentially fragmented in a Fourier transform mass spectrometer to afford acenaphthyne radical anion (9). Structural confirmation of 9 was achieved by converting it to acenaphthenone enolate (13) and demonstrating that this species is identical to the ion produced upon deprotonation of acenaphthenone (5). The reactivity of 9 was explored, and since an electron can serve as a protecting group, we were able to measure the heat of hydrogenation (98 ± 4 kcal mol-1) and the heat of formation (160 ± 4 kcal mol-l) of acenaphthyne (1) via the application of a thermodynamic cycle. Its strain energy (68 kcal mol-1) and acenaphthylene's (10H) first and second C-H bond dissociation energies (117 ± 4 and 84 ± 2 kcal mol-1) also were obtained. Ab initio and density functional theory calculations were carried out on the species of interest to explore their geometries and energetics. Our results were interpreted in comparison to cyclopentyne, and its predicted heat of formation (98 kcal mol-l) and strain energy (59 kcal mol-1) are reported.
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Ramirez,F.,Ramanathan,N.
, p. 3041 - 3042 (1961)
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Conjugated Biradical Intermediates: Spectroscopic, Kinetic, and Trapping Studies of 2,2-Dimethyl-1,3-perinaphthadiyl
Hasler, Erich,Gassmann, Ernst,Wirz, Jacob
, p. 777 - 788 (1985)
The biradical 2,2-dimethyl-1,3-perinaphthadiyl (a) was generated from different precursors, the naphthocyclopropane 1 and the azo copound 2, and from each by three different pathways (pyrolysis, direct photolysis, and triplet sensitization, Scheme 1).The combined evidence from flash photolysis, low-temperature spectroscopy, and product analyses provides a detailed mechanistic picture of the formation and decay of this reactive intermediate which is persistent at 77 K in the triplet ground state (3a) and rather long-lived (400 μs) at room temperature.When formed in its lowest singlet state (1a), the biradical is too short-lived to undergo intersystem crossing to 3a or bimolecular reactions.Thus, 3a is formed exclusively from the excited triplet state of the precursor compounds, 31* or 32*.The monomolecular decay of 3a is retarded by the spin barrier; 3a initiates the polymerization of acrylonitrile and is trapped by 3O2.
Polyethylene glycol radical-initiated benzylic C-H bond oxygenation in compressed carbon dioxide
Wang, Jin-Quan,He, Liang-Nian
, p. 1637 - 1640 (2009)
The PEG radical originating from the thermal/oxidative degradation of PEG in dense CO2 was successfully applied to the oxygenation of benzylic hydrocarbons under organic solvent-free conditions. In addition, in our study, dense CO2 could improve the oxygenation reaction.
High-efficient metal-free aerobic oxidation of aromatic hydrocarbons by N, N-dihydroxypyromellitimide and 1,4-diamino-2,3-dichloroanthraquinone
Chen, Chen,Lv, Zhenguo,Wang, Huibin,Yang, Yuanyuan,Ye, Yicheng,Zhang, Qiaohong,Zhu, Zhuwei
, (2021/12/30)
Metal-free organic catalytic system combining with N, N-dihydroxypyromellitimide (NDHPI) and 1,4-diamino-2,3-dichloroanthraquinone (DADCAQ) was developed for the selective oxidation of hydrocarbon. Being able to simultaneously show good catalytic activity for the oxidation of hydrocarbon and alcohol, NDHPI/DADCAQ was found to be efficient for the conversion of hydrocarbon to ketone. In addition, due to its specific molecular structure, NDHPI was found to be more stable and could supply a PIDNO (pyromellitimide N, N-dioxyl free radical) during the catalytic process. So, higher catalytic activity could be obtained than the famous NHPI even with only half usage, which resolved the problem of high usage (usually 10 mol%) for the organic N-OH compounds to some extent. With 5 mol% NDHPI and 1.25 mol% DADCAQ being used under the conditions of 110 °C and 0.3 MPa molecular oxygen for 7 h, high conversion of ethylbenzene (89.6%), tetralin (98.8%), indene (96.9%), and inert toluene (50.7%) could be selectively converted to the products of acetophenone (93.4%), α-tetralone (97.3%), 1-indanone (98.9%), and benzoic acid (92.4%), respectively.
Selective electrochemical oxidation of aromatic hydrocarbons and preparation of mono/multi-carbonyl compounds
Li, Zhibin,Zhang, Yan,Li, Kuiliang,Zhou, Zhenghong,Zha, Zhenggen,Wang, Zhiyong
, p. 2134 - 2141 (2021/09/29)
A selective electrochemical oxidation was developed under mild condition. Various mono-carbonyl and multi-carbonyl compounds can be prepared from different aromatic hydrocarbons with moderate to excellent yield and selectivity by virtue of this electrochemical oxidation. The produced carbonyl compounds can be further transformed into α-ketoamides, homoallylic alcohols and oximes in a one-pot reaction. In particular, a series of α-ketoamides were prepared in a one-pot continuous electrolysis. Mechanistic studies showed that 2,2,2-trifluoroethan-1-ol (TFE) can interact with catalyst species and generate the corresponding hydrogen-bonding complex to enhance the electrochemical oxidation performance. [Figure not available: see fulltext.]
Ruthenium-Catalyzed Dehydrogenation of Alcohols with Carbodiimide via a Hydrogen Transfer Mechanism
Sueki, Shunsuke,Matsuyama, Mizuki,Watanabe, Azumi,Kanemaki, Arata,Katakawa, Kazuaki,Anada, Masahiro
, p. 4878 - 4885 (2020/06/02)
Ruthenium-catalyzed oxidative dehydrogenation of alcohols using carbodiimide as an efficient hydrogen acceptor has been developed. The protocol exhibits wide substrate scope with good to excellent yields. The results of the kinetic analysis indicated that the reaction mechanism includes the hydrogen transfer process and that the addition of carbodiimide is essential for the reaction system, and the resulting amidine also could react as a hydrogen acceptor.