Synthesis of a novel tetracationic acidic organic salt based on DABCO and its applications as catalyst in the Knoevenagel condensation reactions in water

Synthesis of a novel tetracationic acidic organic salt based on DABCO containing two sulfonic acid groups in the skeleton and four hydrogensulfate groups as counterion is described. Its catalytic efficiency in the Knoevenagel condensation of aldehydes with active cyclic methylene compounds in water is investigated. While 2,2'-(phenylmethylene)bis(3-hydroxy-5,5-dimethylcyclohex-2-enone) derivatives were obtained in 40-98% isolated yields in the reaction of aldehydes with dimedone, the corresponding Knoevenagel adducts were provided in 85-95% yields using 1,3-dimethylbarbituric acid. In addition, a DABCO-based polycationic organic salt polymer was prepared and characterized for the first time.本文报道了一种基于DABCO（1,4-二氮杂双环[2.2.2]辛烷）的新型四阳离子酸性有机盐的合成：该盐分子骨架中含有两个磺酸基团，以四个硫酸氢根作为抗衡离子。本文考察了该盐在水相体系中催化醛与活性环状亚甲基化合物发生克脑文盖尔（Knoevenagel）缩合反应的催化效能。在醛与达米酮（dimedone）的反应中，目标产物2,2'-（苯亚甲基）双（3-羟基-5,5-二甲基环己-2-烯酮）类衍生物的分离产率可达40%~98%；而当以1,3-二甲基巴比妥酸为底物时，对应克脑文盖尔缩合加合物的产率为85%~95%。此外，本文首次合成并表征了一种基于DABCO的多阳离子有机盐聚合物。