- Quinone C-H Alkylations via Oxidative Radical Processes
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A brief survey of radical additions to quinones is reported. Carboxylic acids, aldehydes, and unprotected amino acids are compared as alkyl radical precursors for the mono- or bis- C-H alkylation of several quinones. Two methods for radical initiation are discussed comparing inorganic persulfates and Selectfluor as stoichiometric oxidants. Kinetic analysis reveals dramatic differences in the rate of radical initiation depending on the identity of the radical precursor and oxidant. Synthetic strategies for efficiently producing alkyl-quinones are discussed in the context of selecting optimum radical precursors and initiators depending on quinone identity and functional groups present.
- Hamsath, Akil,Galloway, Jordan D.,Baxter, Ryan D.
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p. 2915 - 2923
(2018/06/12)
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- Steric effects on the cyclability of benzoquinone-type organic cathode active materials for rechargeable batteries
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Benzoquinone derivatives, which undergo reversible twoelectron redox reactions, should afford high capacity as positive electrode materials for rechargeable batteries. Although some benzoquinones have been reported as cathode active materials, their low c
- Yokoji, Takato,Kameyama, Yuki,Sakaida, Shun,Maruyama, Norihiko,Satoh, Masaharu,Matsubara, Hiroshi
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supporting information
p. 1726 - 1728
(2016/02/19)
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- The reaction of nitrile oxide-quinone cycloadducts. III. Reinvestigation of the base-induced isomerization of the 1:1 -C=C-adducts of aromatic nitrile oxides with 2,5-and 2,6-dialkyl-substituted p-benzoquinones
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The structure of the product obtained by the base, induced isomerization of the 1,3-dipolar cycloadduct of 2,5-di-t-butyl-p-benzoquinone with 2,6- dichlorobenzonitrile oxide was determined by X-ray analysis. The t-butyl group at the bridgehead position of the 1,3-dipolar cycloadduct migrated to the neighboring carbonyl carbon atom. This base-induced rearrangement took place with a bulky group, i.e., Et, i-Pr, t-Bu, and Bn at the bridgehead position of nitrile oxide-quinone cycloadducts in an alcoholic media. The driving force of this reaction is considered to be due to stabilization by aromatization from isoxazoline derivatives to isoxazole-fused p-quinol derivatives.
- Mukawa, Takashi,Inoue, Yukihiko,Shiraishi, Shinsaku
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p. 2549 - 2556
(2007/10/03)
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- Catalytic Autoxidation of Benzoquinone Dioximes with Nitrogen Oxides: Steric Effects on the Preparation of Monomeric Dinitrosobenzenes
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A convenient catalytic method for the autoxidation of quinone dioximes to dinitrosobenzenes with dioxygen is based on the presence of small amounts of nitrogen oxides.The catalytic cycle is deduced from the facile chemical oxidation of quinone dioxime to dinitrobenzene with stoichiometric amounts of the 1-electron oxidant, nitrosonium-either as the NO+BF4- salt or the disproportionated ion pair NO+NO3- derived from nitrogen dioxide.The regeneration of NO+ occurs by the subsequent oxidation of nitric oxide (NO) with dioxygen to nitrogen dioxide followed by the disproportionation to nitrosonium nitrate in the presence of electron-rich donors.Indeed, dioximes of various p-benzoquinones are shown to be strong reducing agents by transient electrochemistry.Electrochemical oxidation also leads to dinitrosobenzenes in good yields at anodic potentials of ca. 1.3 V.The substitution of p-dinitrosobenzene with bulky alkyl groups stabilizes the monomeric form, which is otherwise extensively associated.
- Rathore, R.,Kim, J. S.,Kochi, J. K.
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p. 2675 - 2684
(2007/10/02)
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- A New Selective Method for the Homolytic Alkylation and Carboxylation of Quinones by Monoesters of Oxalic Acid
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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.
- Coppa, Fausta,Fontana, Francesca,Lazzarini, Edoardo,Minisci, Francesco
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p. 1299 - 1302
(2007/10/02)
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