Reactions of ethyl cyanoformate with cycloimmonium salts: a direct pathway to fused or substituted azaheterocycles
作者:Cristina M. Al Matarneh、Mircea O. Apostu、Ionel I. Mangalagiu、Ramona Danac
DOI:10.1016/j.tet.2016.05.061
日期:2016.7
Aromatic cycloimmonium salts underwent different reaction pathways when treated with ethyl cyanoformate in triethyl amine medium, including selective γ-cyano substitutions (in case of phenanthrolinium and quinolinium salts) and 3+2 dipolar cycloadditions (for phthalazinium and isoquinolinium salts). When using phthalazinium salts, besides the 3+2 cycloaddition products (imidazo[2,1-a]phthalazines)
当在三乙胺介质中用氰基甲酸乙酯处理时,芳族环亚铵盐会经历不同的反应途径,包括选择性的γ-氰基取代(在菲咯啉鎓和喹啉鎓盐的情况下)和3 + 2偶极环加成反应(对于邻苯二甲酸和异喹啉鎓盐)。当使用phthalazinium盐,除了3个+ 2环加成产物(咪唑并[2,1-一个]酞嗪),我们得到8,8一,16,16一个-tetrahydropyrazino- [2,1-一个; 4,5-一个′]-二酞嗪通过3 + 3环加成二聚化作为副产物。合成的化合物的结构已通过光谱数据和三种新衍生物的X射线衍射证明。