- Hydrogen Atom Transfer (HAT) Processes Promoted by the Quinolinimide-N-oxyl Radical. A Kinetic and Theoretical Study
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A kinetic study of the hydrogen atom transfer (HAT) reactions from a series of organic compounds to the quinolinimide-N-oxyl radical (QINO) was performed in CH3CN. The HAT rate constants are significantly higher than those observed with the phthalimide-N-oxyl radical (PINO) as a result of enthalpic and polar effects due to the presence of the N-heteroaromatic ring in QINO. The relevance of polar effects is supported by theoretical calculations conducted for the reactions of the two N-oxyl radicals with toluene, which indicate that the HAT process is characterized by a significant degree of charge transfer permitted by the π-stacking that occurs between the toluene and the N-oxyl aromatic rings in the transition state structures. An increase in the HAT reactivity of QINO was observed in the presence of 0.15 M HClO4 and 0.15 M Mg(ClO4)2 due to the protonation or complexation with the Lewis acid of the pyridine nitrogen that leads to a further decrease in the electron density in the N-oxyl radical. These results fully support the use of N-hydroxyquinolinimide as a convenient substitute for N-hydroxyphthalimide in the catalytic aerobic oxidations of aliphatic hydrocarbons characterized by relatively high C-H bond dissociation energies.
- Dilabio, Gino A.,Franchi, Paola,Lanzalunga, Osvaldo,Lapi, Andrea,Lucarini, Fiorella,Lucarini, Marco,Mazzonna, Marco,Prasad, Viki Kumar,Ticconi, Barbara
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- Electrochemical Radical Silyl-Oxygenation of Activated Alkenes
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An efficient electrochemical radical silyl-oxygenation of electron-deficient alkenes is demonstrated, which gives access to a variety of new highly functionalized silicon-containing molecules, including β-silyl-cyanohydrin derivatives in good yields with
- Ke, Jie,Liu, Wentan,Zhu, Xujiang,Tan, Xingfa,He, Chuan
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- Kinetics of N-oxyl Radicals' Decay
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N-oxyl radicals of various structures were generated by oxidation of corresponding N-hydroxy compounds with iodobenzene diacetate, [bis(trifluoroacetoxy)]iodobenzene, and ammonium cerium(IV) nitrate in acetonitrile. The decay rate of N-oxyl radicals follows first-order kinetics and depends on the structure of N-oxyl radicals, reaction conditions, and the nature of the solvent and oxidant. The values of the self-decay constants change within 1.4 × 10-4 s-1 for the 3,4,5,6-tetraphenylphthalimide-N-oxyl radical to 1.4 × 10-2 s-1 for the 1-benzotriazole-N-oxyl radical. It was shown that the rate constants of the phthalimide-N-oxyl radicalsê? self-decay with different electron-withdrawing or-donor substituents in the benzene ring are higher than that of the unsubstituted phthalimide-N-oxyl radical in most cases. The solvent effect on the process of phthalimide-N-oxyl radical self-decomposition was investigated. The dependence of the rate constants on the Gutmann donor numbers was shown.
- Hordieieva, Iryna,Kompanets, Mykhailo,Kushch, Olga,Litvinov, Yurii,Novikova, Katerina,Opeida, Iosip,Shendrik, Alexander
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p. 7112 - 7124
(2020/07/07)
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- Design, synthesis and biological evaluation of novel isoindolinone derivatives as potent histone deacetylase inhibitors
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Histone deacetylases (HDACs) as appealing targets for the treatment of many diseases has been studied extensively and its use in cancer care is the most important. Here, we developed a series of novel derivatives containing isoindolinone skeleton. Twelve compounds demonstrated nanomolar IC50 values against HDAC1, and the best compounds were 5a (65.6 nM), 5b (65.1 nM) and 13a (57.9 nM). In vitro, 5a and 5b also showed potent antiproliferative activities against several cancer cell lines, in particular 5b, which behaved better than approved drug chidamide. Morever, enzyme inhibition and western blot assay established 5b to be a selective inhibitor for HDAC1-3. Molecular docking was performed to rationalize the high potency of isoindolinones. Additionally, 5b had more appropriate drug metabolism in human liver microsome (HLM) compared with chidamide and moderate pharmacokinetics properties. These results indicated that 5b was worthy of further biological studies.
- Chen, Xin,Zhao, Shuang,Li, Hongmei,Wang, Xin,Geng, Aixin,Cui, Hao,Lu, Tao,Chen, Yadong,Zhu, Yong
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p. 110 - 122
(2019/02/25)
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- A novel histone deacetylase inhibitors
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The invention belongs to the field of medical chemistry, and particularly relates to a novel histone deacetylase inhibitor and a preparation method thereof, a pharmaceutical combination containing the histone deacetylase inhibitor, and application of the inhibitor in preparing drugs for preventing and/or treating diseases related to histone deacetylase activity out-of-control (especially antitumor application).
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Paragraph 0073; 0076; 0077
(2018/01/11)
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- A complexation promoted organic N-hydroxy catalytic system for selective oxidation of toluene
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Complexation was innovatively utilized to design a novel catalytic system for the selective oxidation of toluene, which runs contrary to the traditional definition of organic metal complex catalysis. In the present system, an N-heteroaromatic ring-contain
- Zhang, Qiaohong,Chen, Chen,Xu, Jie,Wang, Feng,Gao, Jin,Xia, Chungu
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supporting information; experimental part
p. 226 - 230
(2011/04/16)
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