One-pot synthesis of imidazo[1,2-a]pyridines from benzyl halides or benzyl tosylates, 2-aminopyridines and isocyanides
摘要:
A one-pot synthesis of imidazo[1,2-a]pyridines is described. Benzyl halides or benzyl tosylates are oxidized to aldehydes under mild Kornblum conditions which then undergo a three-component reaction with various 2-aminopyridines and isocyanides to afford the imidazo[1,2-a]pyridines in excellent yields. (C) 2011 Elsevier Ltd. All rights reserved.
A microwave-promoted highly flexible and efficientUgi-type multicomponent reaction of heterocyclic amidines with aldehydes and isocyanides catalyzed by zirconium(IV) chloride was developed. The general protocol offered the very reliable synthesis of a library of medicinally important, widely versatile N-fused aminoimidazoles in excellent yields. Poorly reactive heterocyclic amidines, functionally
A new electrostatically enhanced sulfuric acid as a strong Brønstedacidiccatalyst has been developed for multi-component reactions. A positively charged center in the catalyst electrostatically activates it for acid-catalyzed multi-component reactions and afforded desired products in short reaction time and near room temperature in EtOH as a green solvent.Graphical Abstract
Catalytic activity of aqueous cationic polyurethane dispersions: A novel feature of polyurethanes
作者:Hamed Daemi、Reza Rezaieyeh Rad、Mehdi Barikani、Mehdi Adib
DOI:10.1016/j.apcata.2013.08.023
日期:2013.11
Polyurethane ionomers are well-known and user-friendly polymers. Here, we introduce their catalytic activity for organic reactions as a novel aspect of these polymers. We selected an isocyanide-based multicomponent reaction for proving the catalytic activity of polyurethane ionomers. Therefore, a convenient and very mild methodology is described for the preparation of 3-aminoimidazo[1,2-a]pyridines via a three component reaction between 2-aminopyridines, aldehydes and isocyanides in the presence of a cationic polyurethane dispersion at low reaction temperatures, in short reaction times and excellent yields. (C) 2013 Elsevier B.V. All rights reserved.