Kinetics of alkaline hydrolysis of p-substituted benzylidenemalononitriles in 50% aqueous acetonitrile: substituent effects and quantification of the electrophilic reactivity
作者:Nejeh Dhahri、Boubaker Taoufik、Régis Goumont
DOI:10.1002/poc.3286
日期:2014.6
The rate constants of the reaction of p‐X‐substituted benzylidenemalononitriles 1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h with hydroxide ion were measured in 50% water–50% acetonitrile at 20 °C. The experimental kinetic data reveal that the points pertaining to electron donating substituted compounds (X = Me, OMe and NMe2) exhibit negative deviations from the Hammett plot. However, the Yukawa–Tsuno plot for the
在20°C下于50%水–50%乙腈中测量对-X-取代的亚苄基丙二腈1a,1b,1c,1d,1e,1f,1g,1h与氢氧根离子反应的速率常数。实验动力学数据表明,与给电子取代化合物(X = Me,OMe和NMe 2)有关的点与Hammett图具有负偏差。但是,在相同的速率常数下,由汤川-Tsuno图得出了一条具有良好相关系数的良好直线(r 2 = 0.9916)和r值1.15。已经提出通过共振相互作用可能的基态稳定来解释非线性哈米特图的起源。上之间的关系的基础上ë和σ p +,亲电性参数Ë一些benzylidenemalononitriles的1C和1E,1F,1克,1H已被评估。更重要的是,三种化合物1f(E = −7.90),1g(E = −7.80)和1h(E = -7.55)具有很高的亲电性,与4,6-二硝基苯并硒二唑(E = -7.40)相比具有很高的亲电性,该化合物具有代