Generation of Halomethyl Radicals by Halogen Atom Abstraction and Their Addition Reactions with Alkenes
作者:Robynne K. Neff、Yong-Liang Su、Siqi Liu、Melina Rosado、Xinhao Zhang、Michael P. Doyle
DOI:10.1021/jacs.9b05921
日期:2019.10.23
α-Aminoradicals undergo halogen atom abstraction to form halomethyl radicals in reactions initiated by the combination of tert-butyl hydroperoxide, aliphatic trialkylamine, halocarbon, and copper(I) iodide. The formation of the α-aminoradical circumvents preferential hydrogen atom transfer in favor of halogen atom transfer, thereby releasing the halomethyl radical for addition to alkenes. The resulting
α-氨基在由叔丁基过氧化氢、脂肪族三烷基胺、卤代烃和碘化铜(I)的组合引发的反应中经历卤素原子抽吸形成卤甲基自由基。α-氨基自由基的形成避免了有利于卤素原子转移的优先氢原子转移,从而释放卤代甲基自由基以加成到烯烃中。所得自由基加成产物与叔丁基过氧基团相加形成 α-过氧-β,β-二氯丙苯产物,该产物可转化为其相应的 β,β-二氯醇和新型吡啶衍生物。计算分析清楚地解释了氯仿与传统 HAT 的偏差,并建立了正式的氧化加成/还原消除作为最低能量途径。