Silica-Supported Preyssler Nano Particles: A Novel, Green and ReusableCatalyst for Rapid and EfficientOne-Pot Synthesis

Multicomponent reactions (MCRs) are one of the most important protocols in organic synthesis andmedicinal chemistry. They are very fast, economical, facile, easy to work-up and eco-friendly.۱ So, thedesign of new MCRs on one hand, and the full exploitation of already known multicomponent reactionson the other hand, is therefore of considerable current interest.The imidazole ring system is the most important substructures found in a large number of naturalproducts and pharmacologically active compounds.۲ ۱,۲,۴,۵-tetrasubstituted imidazoles are generallysynthesized by one-pot four-component reaction, starting from ۱,۲-dicarbonyl compounds, aldehydes,primary amines and ammonium acetate in presence of Lewis acid catalysts.۲ However, some of theseprevious methods have suffered from one or more drawbacks like high temperature requirement, highlyacidic conditions, significant amounts of waste materials, occurrence of side reactions, low yields and theuse of expensive reagents. Therefore, the development of mild, efficient and environmentally method isstill strongly desirable.In the last two decades, heteropoly acids (HPAs) have found numerous applications as useful andversatile acid catalysts for some acid-catalyzed reactions.۳ HPAs are more reactive catalysts thanconventional inorganic and organic acids for reactions in solution, non-toxic, highly stable towardshumidity, air stable, recyclable, non-explosive, easy to handle, compatible with the environment, andexperimental simplicity.۴ However, there is a need to develop and generate new catalysts of thesecompounds that are more active and effective for applications as solid acid catalysts. So, for the first time,we synthesis and characterization of silica-supported Preyssler nanoparticles (SPNP),۵ and studied itscatalytic activity for different organic reactions.

کلیدواژه ها:

Solid acid ، Preyssler ، Green catalyst ، One-pot reaction