Institute of Chemistry, St. Petersburg State University, Universitetskii pr. 26, 198504 St. Petersburg, Russia.
Molecules. 2020 Dec 17;25(24):5977. doi: 10.3390/molecules25245977.
The influence of steric repulsion between the NMe group and a second -(-)substituent in the series of 1-dimethylaminonaphthalene and ,-dimethylanilene -oximes on the ease of the NMe group's intramolecular nucleophilic substitution is studied. Possible reaction intermediates for three mechanisms are calculated (ωB97xd/def-2-TZVP), and their free Gibbs energies are compared to model reaction profiles. Supporting experiments have proved the absence of studied reactivity in the case of simple 2-dimethylaminobenzaldoxime, which allowed us to establish reactivity limits. The significant facilitation of NMe group displacement in the presence of bulky substituents is demonstrated. The possibility of fused isoxazoles synthesis via the intramolecular nucleophilic substitution of a protonated NMe group in the aniline and naphthalene series is predicted.
研究了 1-二甲基氨基萘和 -二甲基苯胺 -肟系列中 NMe 基团和第二个 -(-)取代基之间的空间排斥对 NMe 基团分子内亲核取代的影响。计算了三种机制的可能反应中间体（ωB97xd/def-2-TZVP），并比较了它们的自由吉布斯能与模型反应轮廓。支持性实验已经证明了在简单的 2-二甲基氨基苯甲醛肟的情况下不存在研究的反应性，这使我们能够确定反应性极限。在存在大体积取代基的情况下，NMe 基团取代的显著促进作用得到了证明。通过苯胺和萘系列中质子化的 NMe 基团的分子内亲核取代预测了稠合异恶唑的合成可能性。
