Comparison of the One-Bond Nucleophilicities of Monomethyl- and Dimethyl-Substituted 1,3-Butadienes
作者:Herbert Mayr、Manfred Hartnagel
DOI:10.1002/jlac.199619961211
日期:1996.12
The kinetics of the reactions of (E)-2-methyl-1,3-pentadiene (2a), 4-methyl-1,3-pentadiene (2b), and (Z)-1,3-pentadiene (2c) with benzhydryl cations have been studied photometrically in dichloromethane solution. Substitution of these rate constants into the linear free enthalpy relationship lgk=s(N + E) yielded the nucleophilicity parameters N for these dienes. The influence of methyl groups on the
(E)-2-甲基-1,3-戊二烯(2a),4-甲基-1,3-戊二烯(2b)和(Z)-1,3-戊二烯(2c)与已经在二氯甲烷溶液中以光度法研究了苯甲基阳离子。将这些速率常数代入线性自由焓关系lg k = s(N + E),即可得到这些二烯的亲核参数N。讨论了甲基对1,3-丁二烯亲核反应性的影响,并提出了一种估计其他烷基化1,3-二烯反应性的系统。