Kushch Olga, Hordieieva Iryna, Novikova Katerina, Litvinov Yurii, Kompanets Mykhailo, Shendrik Alexander, Opeida Iosip
L.M. Litvinenko Institute of Physico-Organic Chemistry and Coal Chemistry, National Academy of Sciences of Ukraine, Kyiv 02660, Ukraine.
Faculty of Chemistry, Biology and Biotechnologies, Vasyl' Stus Donetsk National University, Vinnytsia 21021 Ukraine.
J Org Chem. 2020 Jun 5;85(11):7112-7124. doi: 10.1021/acs.joc.0c00506. Epub 2020 May 26.
-oxyl radicals of various structures were generated by oxidation of corresponding -hydroxy compounds with iodobenzene diacetate, [bis(trifluoroacetoxy)]iodobenzene, and ammonium cerium(IV) nitrate in acetonitrile. The decay rate of -oxyl radicals follows first-order kinetics and depends on the structure of -oxyl radicals, reaction conditions, and the nature of the solvent and oxidant. The values of the self-decay constants change within 1.4 × 10 s for the 3,4,5,6-tetraphenylphthalimide--oxyl radical to 1.4 × 10 s for the 1-benzotriazole--oxyl radical. It was shown that the rate constants of the phthalimide--oxyl radicals' self-decay with different electron-withdrawing or -donor substituents in the benzene ring are higher than that of the unsubstituted phthalimide--oxyl radical in most cases. The solvent effect on the process of phthalimide--oxyl radical self-decomposition was investigated. The dependence of the rate constants on the Gutmann donor numbers was shown.
通过在乙腈中用二乙酸碘苯、[双（三氟乙酰氧基）]碘苯和硝酸铈（IV）铵氧化相应的 - 羟基化合物，生成了各种结构的 - 氧基自由基。 - 氧基自由基的衰减速率遵循一级动力学，并且取决于 - 氧基自由基的结构、反应条件以及溶剂和氧化剂的性质。自衰减常数的值在3,4,5,6 - 四苯基邻苯二甲酰亚胺 - 氧基自由基的1.4×10⁻⁵ s⁻¹到1 - 苯并三唑 - 氧基自由基的1.4×10⁻³ s⁻¹范围内变化。结果表明，在大多数情况下，苯环上带有不同吸电子或供电子取代基的邻苯二甲酰亚胺 - 氧基自由基的自衰减速率常数高于未取代的邻苯二甲酰亚胺 - 氧基自由基。研究了溶剂对邻苯二甲酰亚胺 - 氧基自由基自分解过程的影响。显示了速率常数对古特曼给体数的依赖性。
