An Efficient, Regioselective, Versatile Synthesis of N-Fused 2- and 3-Aminoimidazoles via Ugi-Type Multicomponent Reaction Mediated by Zirconium(IV) Chloride in Polyethylene Glycol-400
作者:Sankar Guchhait、Chetna Madaan
DOI:10.1055/s-0028-1087915
日期:2009.3
An Ugi-type multicomponent reaction of heterocyclicamidines with aldehydes and isocyanides catalyzed by zirconium(IV) chloride in PEG-400 was developed. The protocol offers the rapid, environment friendly, regioselective and versatile synthesis of medicinally important N-fused 2- and 3-aminoimidazoles in good to high yields. The combination of catalyst and solvent, that was judiciously explored, was
开发了 PEG-400 中氯化锆 (IV) 催化的杂环脒与醛和异氰化物的 Ugi 型多组分反应。该协议提供了快速、环境友好、区域选择性和多功能的医学上重要的 N-融合 2-和 3-氨基咪唑的合成,产量高。明智地探索了催化剂和溶剂的组合,对于该方法的区域选择性和多功能性至关重要。
Three Novel Sequential Reactions for the Facile Synthesis of a Library of Bisheterocycles Possessing the 3-Aminoimidazo[1,2-a]pyridine Core Catalyzed by Bismuth(III) Chloride
作者:Aziz Shahrisa、Somayeh Esmati
DOI:10.1055/s-0032-1318221
日期:——
Novel, one-pot, two-step, sequential protocols for the synthesis of 1,4-phenylene bisheterocyclic compounds have been developed. Successive sequencing of the Groebke-Blackburn-Bienayme reaction with Ugi-azide, Hantzsch and Biginelli reactions results in rapid and efficient formation of bisheterocyclic compounds. A simple, fast and high yielding method for the synthesis of 3-aminoimidazo[1,2-a]pyridines catalyzed by bismuth(III) chloride under solvent-free conditions is reported. Bismuth(III) chloride is also an efficient catalyst for the Ugi-azide reaction under solvent free conditions.