high-yielding, one-step procedure is described for the preparation of a wide range of stable iminium salts by direct combination of an aldehyde or a ketone with a secondary free amine in the presence of an ammonium salt. The broad scope of the method is illustrated by the preparation of iminium ions derived fromaldehydes, cyclic/acyclic ketones, and cyclic/acyclic secondary amines.
Inhibition and Stabilization: Cucurbituril Induced Distinct Effects on the Schiff Base Reaction
作者:Wanjun Gong、Jun Ma、Zhiyong Zhao、Fang Gao、Feng Liang、Haijun Zhang、Simin Liu
DOI:10.1021/acs.joc.6b02971
日期:2017.3.17
CB[7], the condensation reaction of aldehyde and primary amine is dramatically inhibited. In contrast, the presence of CB[7] does tremendously stabilizeiminium cation in water through ion–dipole interactions. A single crystal structure of the complex of iminiumion 7 with CB[7] grown in water is reported.
1 H NMR光谱和单X射线晶体学探讨了葫芦[7]尿素(CB [7])对水溶液中席夫碱反应的不同影响。使用CB [7],可以极大地抑制醛与伯胺的缩合反应。相反,CB [7]的存在通过离子-偶极相互作用极大地稳定了水中的亚胺阳离子。报道了在水中生长的亚胺离子7与CB [7]的配合物的单晶结构。