Evidence for Divalent Iodine (9-I-2) Radical Intermediates in the Thermolysis of (<i>tert</i>-Butylperoxy)iodanes. An Unusually Efficient Deiodination of <i>o</i>-Iodocumyl Alcohols by Cyclohexyl Radicals<sup>1</sup>
作者:Darko Dolenc、Božo Plesničar
DOI:10.1021/ja9636404
日期:1997.3.1
3-dimethyl-1H-1,2-benziodoxoles (2a and 2b) and 1-(tert-butylperoxy)-3,3-bis(trifluoromethyl)-5-methyl-1H-1,2-benziodoxole (2c) were prepared from chloroiodanes 1a−c and tert-butyl hydroperoxide in the presence of potassium tert-butoxide in tetrahydrofuran. Products, kinetic data for the decomposition of 2 in cyclohexane, benzene, toluene, and acetonitrile (Ea = 31.0 ± 1.0 kcal/mol, log A = 17.0 ± 0.5; 35−70
1-(叔丁基过氧基)-3,3-二甲基-1H-1,2-苯并氧杂(2a和2b)和1-(叔丁基过氧基)-3,3-双(三氟甲基)-5-甲基-1H-在叔丁醇钾的存在下,在四氢呋喃中由氯碘烷 1a-c 和叔丁基氢过氧化物制备 1,2-苯并氧杂环戊烷 (2c)。产物,2 在环己烷、苯、甲苯和乙腈中分解的动力学数据(Ea = 31.0 ± 1.0 kcal/mol,log A = 17.0 ± 0.5;35-70 °C),以及 2c 的分解速率增加在存在磁场(7 T)的情况下,苯-d6 中的 2 中的 I-O 键均裂并形成碘代基(9-I-2)和叔丁基过氧自由基是主要的分解步骤。在环己烷中 2c 的分解过程中几乎定量地形成碘环己烷是由于环己基与 2-(2-iodo-5-methylphenyl)-1,1,1,3,3,3-hexafluoro-2 发生了意想不到的反应-丙醇,2c的主要分解产物。o-io 脱碘的单独研究结果