Further study of axial chirality due to an acyclic imide N–Ar bond: control of rotational barrier by electronic effects of acyl groups
作者:Kazuhiro Kondo、Takeko Iida、Hiroko Fujita、Tomoko Suzuki、Ryoko Wakabayashi、Kentaro Yamaguchi、Yasuoki Murakami
DOI:10.1016/s0040-4020(01)00295-2
日期:2001.5
Studies on stability to racemization in a series of optically active N-aroyl-N-(2-t-butylphenyl)acetamides 2a–g (X=NMe2, OMe, Me, H, F,Cl, CF3), depending on the electronic effect of their aroyl groups, are described. It has been revealed that the stability of 2 bearing stronger electron-withdrawing groups on the aroyl benzene ring was enhanced, with linear correlation between the ΔG‡ and Hammett's
一系列光学活性N-芳酰基-N-(2-叔丁基苯基)乙酰胺2a–g(X = NMe 2,OMe,Me,H,F,Cl,CF 3)的消旋稳定性研究描述了其芳酰基的电子效应。已经发现,芳基苯环上带有2个较强吸电子基团的稳定性得到增强,并且ΔG ‡和Hammett的σp对位取代常数2a–g之间呈线性相关。此外,旋光酰亚胺2a–g的绝对构型通过与(S)-N-(2-叔丁基苯基)-N-(4-三氟甲基苯甲酰基)丙酰胺(5b)的CD光谱比较确定了(R a,2 S)-N-(2-叔丁基苯基)-N-(4-三氟甲基苯甲酰基)-2-乙酰氧基丙酰胺(4b),其绝对构型通过X射线分析确定。