Synthesis of Environmentally Friendly, Magnetic Acid-type Calix[4]arene Catalyst for Obtaining Biginelli Adducts

Publication date: Available online 8 June 2019Source: Journal of Saudi Chemical SocietyAuthor(s): Carlos Henrique Callegario Zacchi, Sara Silveira Vieira, José Domingos Ardisson, Maria Helena Araujo, Ângelo de FátimaAbstractAn immobilized p-sulfonic acid calix[4]arene was synthesized on the surface of silica-coated Fe3O4 nanoparticles. Due to the combination of the magnetic recovery and the acid properties, it acted as a robust, safe and environmentally friendly catalyst for the one-pot synthesis of Biginelli adducts under microwave irradiation and solvent-free conditions. A series of Biginelli adducts were obtained in moderate to excellent yields, and most importantly, the catalyst could be easily recovered by an external magnet and reused five times without significant loss of catalytic activity (ca. 80% yield for all reuses using 0.64 mol% of the catalyst).Graphical abstractp-Sulfonic acid calix[4]arene immobilized on the surface of silica-coated Fe3O4 nanoparticle efficiently catalyzes the synthesis of Biginelli adducts.
Source: Journal of Saudi Chemical Society - Category: Chemistry Source Type: research