Single-parameter versus dual-parameter correlation for radical reactions. Addition of bromine atoms to ?-methylstyrenes
作者:Xi-kui Jiang、Wayne Wei-zhong Liu、Shi-hui Wu
DOI:10.1002/poc.610070207
日期:1994.2
developed for measuring the relative rates of addition of bromine atoms to eleven substituted α-methylstyrenes (1-Y, with Y = CF3, NO2, F, CN, Cl, Br, CO2Me, Me, COMe, OMe and SMe). The reaction was run in tetrahydrofuran in the presence of HBr, O2 and dibutyl peroxyoxalate at 30°C. All products were derived from the YC6H4CMeCH2Br adduct radicals, which were immediately intercepted by O2. Correlation
开发了一种严格的程序来测量向11个取代的α-甲基苯乙烯(1-Y,Y = CF 3,NO 2,F,CN,Cl,Br,CO,2 Me,Me,COMe的溴原子加成的相对速率,OMe和SMe)。反应在30℃下在HBr,O 2和过氧草酸二丁酯存在下于四氢呋喃中进行。所有产物均来自YC 6 H 4 CMeCH 2 Br加合物自由基,这些自由基立即被O 2拦截。所有数据的相关性分析证实了这样的主张:在没有可测量的空间效应的情况下,自由基加成的相对速率只能通过双参数方程式关联,而不能通过单参数方程式关联。其中σ的各种组合*和σ X,所述(σ JJ * +σ MB)组合产生最好的相关性。