Selective Synthesis and Cycloaddition Reactions of New Azomethine Imines Containing a 1,2,4-Triazine Ring
作者:Csilla Gróf、Gábor Hegedűs、Zsuzsanna Riedl、György Hajós、Orsolya Egyed、Antal Csámpai、Veronika Kudar、Branko Stanovnik
DOI:10.1002/ejoc.200500137
日期:2005.8
The reactions of 4,5-dihydro[1,2,4]triazolo[3,4-c]benzo[1,2,4]triazines with aromatic aldehydes gave stable iminium salts which were deprotonated to give new azomethine imines. These new mesomeric betaines underwent 1,3-dipolar cyclization reactions to yield new tetra- and pentacyclic heterocycles. X-ray analysis and decoupling NMR experiments unambiguously supported the fact that these transformations
4,5-二氢[1,2,4]三唑并[3,4-c]苯并[1,2,4]三嗪与芳香醛的反应得到稳定的亚胺盐,该盐被去质子化得到新的偶氮甲碱亚胺。这些新的内消旋甜菜碱经过 1,3-偶极环化反应生成新的四环和五环杂环。X 射线分析和去耦 NMR 实验明确支持这样一个事实,即这些转化是区域选择性的,并且在每种情况下亚胺部分都在 N-5 原子处形成。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)