Magnetic sulfonated polysaccharides as efficient catalysts for synthesis of isoxazole-5-one derivatives possessing a substituted pyrrole ring, as anti-cancer agents.

Four polysaccharides (chitosan, cellulose, starch, and pectin) were magnetized with magnetic iron oxide (FeO) and then sulfonated (except pectin) with chlorosulfonic acid. The obtained solid acids were used as a catalyst in three-component reactions between -substituted-2-formylpyrrole, hydroxylamine-hydrochloride, and β-keto esters for the synthesis of 4-(2-pyrrolyl) methylene-isoxazole-5-ones. The optimal catalyst system was selected and studied by IR, SEM, TEM and XRD methods.

Magnetic chitosan nanocomposite: As a novel catalyst for the synthesis of new derivatives of N-sulfonylamidine and N-sulfonylimidate.

This study reports the synthesis and characterization of a highly active catalyst based on chelated copper iodide on magnetic chitosan-salicylaldehyde Schiff base. This catalyst was successfully used for the three-component reaction of N-propargylphthalimide, tosylazide, and NH or OH containing nucleophiles to access new classes of N-sulfonylamidine or N-sulfonylimidate derivatives. The products, which were constructed via an in situ generated sulfonyl keteneimine intermediate, were obtained in good to excellent yields.