期刊
JOURNAL OF ORGANIC CHEMISTRY
卷 76, 期 11, 页码 4645-4651出版社
AMER CHEMICAL SOC
DOI: 10.1021/jo200660d
关键词
-
资金
- Ministero dell'Istruzione dell'Universita e della Ricerca (MIUR)
A kinetic study of the hydrogen atom abstraction reactions from propanal (PA) and 2,2-dimethylpropanal (DMPA) by the cumyloxyl radical (CumO*) has been carried out in different solvents (benzene, PhCl, MeCN, t-BuOH, MeOH, and TFE). The corresponding reactions of the benzyloxyl radical (BnO*) have been studied in MeCN. The reaction of Cum. with 1,4-cyclohexadiene (CHD) also has been investigated in TFE solution. With CHD a 3-fold increase in rate constant (k(H)) has been observed on going from benzene, PhCl, and MeCN to TFE. This represents the first observation of a sizable kinetic solvent effect for hydrogen atom abstraction reactions strong HBD solvents influence the hydrogen abstraction reactivity been observed on going from benzene and PhCl to MeOH and TFE, lone pair and the solvent in the transition state. The similar k(H) values point toward differential hydrogen bond interactions of the latter The small reactivity ratios observed for the reactions of Cum. and from hydrocarbons of CumO*. With PA and indicative of hydrogen-bond observed for the reactions solvent with the substrate BnO. with PA and DMPA by alkoxyl radicals and indicates that DMPA a significant decrease in kH has interactions between the carbonyl of the aldehydes in MeOH and TFE and the radical in the transition state. (kH(BnO*)/k(H)(CumO*) = 1.2 and 1.6, respectively) indicate that with these substrates alkoxyl radical sterics play a minor role.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据