Transmission of polar substituent effects through the bicyclo[2.2.2]octane ring system as monitored by NMR shifts: A13C NMR study of 4-substituted-1-methylbicyclo[2.2.2]octanes
作者:William Adcock、Anil N. Abeywickrema、V. Sankar Iyer、Gaik B. Kok
DOI:10.1002/mrc.1260240306
日期:1986.3
substituent chemical shifts (SCS) are reported for the methyl group of a series of 4‐substituted 1‐methylbicyclo[2.2.2]octanes covering a wide range of electronic substituent effects. Unlike the 13C SCS of the α‐carbon centre in various unsaturated side‐chain probes attached to the bicyclo[2.2.2]octane ring, which are mainly proportional to substituent field effects (σF), the 13CH3, SCS are found to display
据报道,碳 13 取代基化学位移 (SCS) 是一系列 4 取代的 1-甲基双环 [2.2.2] 辛烷的甲基,涵盖了广泛的电子取代基效应。与连接到双环 [2.2.2] 辛烷环的各种不饱和侧链探针中 α-碳中心的 13C SCS 不同,13C SCS 主要与取代基场效应 (σF) 成正比,发现 13CH3、SCS对取代基电负性效应以及场参数的明确统计依赖性。对极性磁化率参数(ρF;CDCl3 和 CCl4)的独立测量提供了对多元分析统计分析有效性的有力支持。对于 CCl4 作为溶剂,计算了白金汉方程对 CH3 组的线性电场效应的系数 (A)。