Synthesis and kinetic investigation of the selective acidolysis of para-substituted N-benzyl- or N-phenyl-N-phenylacetyl-α,α-dialkylglycine cyclohexylamides
作者:Filipa C.S.C. Pinto、Sílvia M.M.A. Pereira-Lima、Cristina Ventura、Lídia Albuquerque、Raquel Gonçalves-Maia、Hernâni L.S. Maia
DOI:10.1016/j.tet.2006.05.078
日期:2006.8
biparametric relationships and the results were analysed in terms of structure–reactivity in connection with the sensitivity of the reaction rates to the electronic contributions of the various substituents at position 4 of the aromatic rings. The results allowed comparison with information obtained in previous investigations and rationalise the contribution of the substituent at the nitrogen atom to the
通过Ugi-Passerini反应合成了N-苯基乙酰基-N-苄基-α,α-二甲基甘氨酸环己酰胺的几种衍生物及其α,α-二苄基甘氨酸类似物。另外,合成了一些前者的类似物,但在氮原子上具有N-苯基而不是苄基。这三组化合物各自在N-苄基的4位(和N-苯基)基团。将这些加合物用TFA酸解以获得相应的游离酸,通过HPLC监测反应并出于动力学目的收集数据。将动力学数据提交给Hammett单参数和双参数关系,并根据结构反应性以及反应速率对芳环第4位各种取代基的电子贡献的敏感性进行分析。结果允许与先前研究中获得的信息进行比较,并使氮原子上的取代基对C-末端酰胺键的不稳定性的贡献合理化。