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 of 1,4-dihydropyridines from β-dicarbonyl compounds, aldehyde, and ammonium acetate is reported using sulfonic acid-functionalized silica at 90 °C under solvent-free conditions with good to excellent yields. The catalyst is easily prepared, stable (up to 300 ° C), reusable, and efficiently used under reaction conditions.