Sulfonic acid-functionalized silica: a remarkably efficient heterogeneous reusable catalyst for the one-pot synthesis of 1,4-dihydropyridines

摘要

An efficient one-pot method for the synthesis of1,4-dihydropyridines from eta-dicarbonyl compounds, aldehyde, andammonium acetate is reported using sulfonic acid-functionalized silicaat 90 °C under solvent-free conditions with good to excellent yields.The catalyst is easily prepared, stable (up to 300 °C), reusable, andefficiently used under reaction conditions.