酞嗪-2-二氰基甲烷鎓盐的串联环化反应及新型六环咪唑并[2,1-a]酞嗪的构建

Cascade Cycloaddition Reaction for the Construction of Novel Hexacyclic Imidazo[2,1-a]phthalazine

酞嗪-2-二氰基甲烷鎓盐是一类研究相对较少的1,3-偶极子,目前关于其化学反应的报道主要局限于1,3-偶极环加成反应。本研究发展了一种酞嗪-2-二氰基甲烷鎓盐在1,3-偶极环加成以外的新反应模式,以酞嗪-2-二氰基甲烷鎓盐与取代2-(羟基(苯基)甲基)苯酚为原料,在质子酸的催化下经历[2+4]环加成-串联环化历程,合成了7个不同取代的六环咪唑并[2,1-a]酞嗪产物,其结构经^(1)H NMR,^(13)C NMR和HR-MS(ESI)表征。

Compared with other types of 1,3-dipoles,the chemical reaction of phthalazinium-2-dicyanomethanide is much less explored.This work developed a new reaction mode of phthalazinium-2-dicyanomethanide beyond 1,3-dipole cycloadditions.Using phthalazine-2-dicyanomethane salt and substituted 2-(hydroxy(phenyl)methyl)phenol as substrates under the catalysis of protic acid,seven different substituted hexacyclic imidazo[2,1-a]phthalazine products were constructed through[2+4]cycloaddition-intramolecular cyclization.Their structures were characterized by^(1)H NMR,^(13)C NMR and HR-MS(ESI).