Generation of 15N labelled bis(polyfluoroalkyl) nitroxides and their hydrogen-abstraction reactions with alkanes, alkylbenzenes and aldehydes
作者:Cheng-Xue Zhao、Guo-Fei Chen、Xi-Kui Jiang
DOI:10.1016/s0022-1139(00)81074-x
日期:1988.3
Blue solutions containing 15 labelled bis(polyfluoralkyl) nitroxides and spin traps, polyfluoronitrosoalkanes, were conveniently made from the reactions of Na15NO2 with polyfluoro-compounds, (RFCO2) and RFSO2Br in F113. It has been found that the nitroxides effected fast H-abstraction from alkanes, alkylbenzenes, aldehydes and the radicals derived from the substrates were in turn effectively trapped
由Na 15 NO 2与多氟化合物(R F CO 2)和R F SO 2 Br在F113中的反应可方便地制备包含15个标记的双(聚氟烷基)氮氧化物和自旋阱,多氟亚硝基链烷的蓝色溶液。已经发现,氮氧化物有效地从烷烃,烷基苯,醛中快速吸氢,而衍生自底物的自由基又被R F 15 NO有效地捕获,得到15 N标记的可通过ESR检测的自旋加合物。N越大(15 N)值以及氮氧化物和自旋加合物的简单拆分,使得对H原子吸收和其他自由基反应的动力学研究变得十分可行。
Bis(perfluoroalkyl) nitroxides and perfluoroalkyl nitroalkyl nitroxides generated in SET reactions between perfluorodiacyl peroxides and nitroalkane salts
ESR detection of bis(perfluoroalkyl) nitroxides 11 and perfluoroalkyl nitroalkyl nitroxides 12 in accord with expected products suggests an electron transfer mechanism for the reactions between nitroalkane salts 1 and perfluorodiacyl peroxides 2. Nitroxides 11 and 12 are the spin-adducts of radical intermediates R1R2C·NO2 (3) and R·f (10) with the nitroso-trap RfNO (9) generated in the reactions. These
根据预期产物对双(全氟烷基)氮氧化物11和全氟烷基硝基烷基氮氧化物12的ESR检测表明,硝基烷盐1与全氟二酰过氧化物2之间反应的电子转移机理。硝基氧化物11和12是自由基中间体R 1 R 2 C · NO 2(3)和R · f(10)与亚硝基阱R f NO(9)的自旋加合物)在反应中生成。这些反应已成为一些含氮底物单电子氧化机理研究中的有用技术。
Unexpected, Latent Radical Reaction of Methane Propagated by Trifluoromethyl Radicals
作者:Nima Zargari、Pierre Winter、Yong Liang、Joo Ho Lee、Andrew Cooksy、K. N. Houk、Kyung Woon Jung
DOI:10.1021/acs.joc.6b01903
日期:2016.10.21
Thorough mechanistic studies and DFT calculations revealed a background radical pathway latent in metal-catalyzed oxidation reactions of methane at low temperatures. Use of hydrogen peroxide with TFAA generated a trifluoromethylradical (•CF3), which in turn reacted with methane gas to selectively yield acetic acid. It was found that the methyl carbon of the product was derived from methane, while
Reactivity and properties of bis(chlorodifluoroacetyl) peroxide generated <i>in situ</i> from chlorodifluoroacetic anhydride for chlorodifluoromethylation reactions
作者:Shintaro Kawamura、Cassandra J. Henderson、Yuma Aoki、Daisuke Sekine、Shū Kobayashi、Mikiko Sodeoka
DOI:10.1039/c8cc05905e
日期:——
We developed a practical chlorodifluoromethylation reaction mediated by diacyl peroxide generated in situ from chlorodifluoroacetic anhydride. Allylic and amino-chlorodifluoromethylations of alkenes proceeded well with the combination of this reagent, Cu(II) catalyst and a pyridine additive. Carbo- and aromatic chlorodifluoromethylations proceeded under metal-free conditions.
Connecting Organometallic Ni(III) and Ni(IV): Reactions of Carbon-Centered Radicals with High-Valent Organonickel Complexes
作者:James R. Bour、Devin M. Ferguson、Edward J. McClain、Jeff W. Kampf、Melanie S. Sanford
DOI:10.1021/jacs.9b02411
日期:2019.6.5
one-electron interconversions of isolable NiIII and NiIV complexes through their reactions with carbon-centered radicals (R•). First, model NiIII complexes are shown to react with alkyl and aryl radicals to afford NiIV products. Preliminary mechanistic studies implicate a pathway involving direct addition of a carbon-centered radical to the NiIII center. This is directly analogous to the known reactivity of