Kinetics and mechanisms of nucleophilic displacements with heterocycles as leaving groups. Part 8. Conductimetric and spectrophotometric rate constants for the reactions of pyridinium and related cations with piperidine in chlorobenzene
作者:Alan R. Katritzky、Yu Xiang Ou、Joan Ellison、Giuseppe Musumarra
DOI:10.1039/p29830001421
日期:——
which the spectrophotometric method fails. It gives equivalent results. NN′-Dimethylthiourea displaces heterocyclic leaving groups at rates similar to those for piperidine. Compared with α-hydrogen, α-methyl groups render pyridine a less effective leaving group, whereas α-ethoxycarbonyl groups show a large rate enhancement.
开发了一种电导法以获得分光光度法失败的标题反应的速率。它给出了等效的结果。NN “-Dimethylthiourea取代以类似于那些哌啶率杂环离去基团。与α-氢相比,α-甲基使吡啶成为较低效的离去基团,而α-乙氧羰基则显示出较大的速率增强。