Generation and trapping of non-aromatic cycloimines via diazotization/dediazotization of N-amino cyclic amines: theoretical and experimental results
作者:Minita Ojha、Raj K. Bansal
DOI:10.1007/s11224-020-01567-z
日期:2020.12
1-amino-4-methylpiperazine with tert. -butyl nitrite followed by dediazotization to generate transiently the corresponding cycloimines, which could be trapped with dimethyl acetylenedicarboxylate. to afford new annelated pyridine derivatives, namely tetramethyl 9H -5,6,7,8-tetrahydroquinolizine-1,2,3,4-tetracarboxylate, tetramethyl 5,6,8,9-tetrahydropyrido[2,1-c][1,4]oxazine-1,2,3,4-tetracarboxylate and
在 DFT (B3LYP/6-31+G(d)) 水平对 N-氨基哌啶和 N-氨基吗啉的模型重氮化/去重氮化的理论研究表明,相应的环亚胺可以瞬时生成,可以用乙炔二甲酸二甲酯捕获(DMAD),以形成1,4-偶极接着后者的环加成与DMAD的第二分子,得到相应的吡啶并 - 稠合的产品。所有步骤都具有低活化自由能垒,并且在热力学上是有利的。基于理论结果,我们成功地进行了N-氨基环胺的重氮化,即N-氨基哌啶、4-氨基吗啉和1-氨基-4-甲基哌嗪与叔。-亚硝酸丁酯,然后去重氮化以瞬时生成相应的环亚胺,它可以被乙炔二羧酸二甲酯捕获。提供新的退火吡啶衍生物,即四甲基 9H -5,6,7,8-四氢喹啉-1,2,3,4-四羧酸酯,四甲基 5,6,8,9-四氢吡啶并[2,1-c][1 ,4]恶嗪-1,2,3,4-四羧酸酯和四甲基 9H -5,6,7,8-四氢-7-甲基吡啶并[1,2-a]吡嗪-1,2,3,4-四羧酸酯,其中被适当地表征。