Stability of carbonium ions. Part 3. The transmission of substituent effects across the fluorene and biphenyl systems
作者:Roger Bolton、Rita E. M. Burley
DOI:10.1039/p29770000426
日期:——
The effects of substituents (X) upon the rates of solvolysis of α-(7-X-fluoren-2-yl)benzyl chlorides parallel those of substituents in the corresponding reaction of α-(4-X-fluoren-2-yl)benzyl chlorides, although the former is the more susceptible system. These results are consistent with regarding fluorene as a planar biphenyl structure. Both aromatic systems transmit substituent effects less well
取代基(X)对α-(7-X-芴-2-基)苄基氯的溶剂分解速率的影响与取代基在相应的α-(4-X-芴-2-基)反应中的速率平行苄基氯,尽管前者是较易感的系统。这些结果与将芴视为平面联苯结构是一致的。两种芳族体系的传递取代基效果均不如苯体系,但取代基影响溶剂分解速率的相对能力在所有三个体系中均相同。这表明复合电子(I,M)取代基的传输方式如何,其取代基的贡献都相似,因此没有证据表明一种选择性的,距离依赖性的电子贡献者受到抑制,因此I和M贡献可能都得到了实质性发展在带有取代基的芳族原子处并从其传播。