Zeolite-catalyzed synthesis of 2,3-unsubstituted benzo[b]furans via the intramolecular cyclization of 2-aryloxyacetaldehyde acetals
作者:Nan Sun、Peng Huang、Yifan Wang、Weimin Mo、Baoxiang Hu、Zhenlu Shen、Xinquan Hu
DOI:10.1016/j.tet.2015.05.029
日期:2015.7
An efficient and environmentally benign heterogeneous catalytic process for the synthesis of 2,3-unsubstituted benzo[b]furans has been established via the intramolecular cyclization of 2-aryloxyacetaldehyde acetals. By utilizing tin-exchanged H-β zeolite (Sn-β) as catalyst, a wide range of functionalized 2,3-unsubstituted benzo[b]furans could be prepared in good to excellent yields. The Sn-β zeolite
通过2-芳氧基乙醛缩醛的分子内环化,已经建立了一种有效的,对环境无害的非均相催化方法,用于合成2,3-未取代的苯并[ b ]呋喃。通过使用锡交换的H-β沸石(Sn-β)作为催化剂,可以以良好或极好的收率制备各种功能化的2,3-未取代的苯并[ b ]呋喃。Sn-β沸石催化剂还在间位取代的2-芳氧基乙醛缩醛的环化上表现出优异的形状选择性,并且优选形成高达97%的区域选择性的6-取代的异构体。而且,Sn-β沸石可以容易地回收和再利用而没有任何明显的活性损失。