The β-(Phosphatoxy)alkyl Radical Rearrangement. Rate Constants, Arrhenius Parameters, and Structure Activity Relationships
作者:David Crich、Xian-Yun Jiao
DOI:10.1021/ja961275a
日期:1996.1.1
Rate constants for the migration of a series of p,p-disubstituted β-(diarylphosphatoxy)alkyl migrations have been determined in benzene at reflux by competition against the benzeneselenol clock reaction. There is a strong linear correlation of log(k) with the Hammett σp but not with various σ• parameters indicating that the migration occurs through a highly polarized transition state resembling an
通过与苯硒醇时钟反应的竞争,在回流的苯中确定了一系列 p,p-二取代 β-(二芳基磷酸酯氧基) 烷基迁移的速率常数。log(k) 与 Hammett σp 有很强的线性相关性,但与各种 σ• 参数无关,表明迁移是通过高度极化的过渡态发生的,类似于松散结合到磷酸根阴离子的烯烃自由基阳离子。发现描述 β-苯基-β-(二苯基磷酸酯氧基)乙基自由基在甲苯中迁移的阿伦尼乌斯方程为 log(kR) = (10.2 ± 0.8) - (7.0 ± 1.0)/2.3RT。