Silica-Supported LiHSO4 as a Highly Efficient, Heterogeneous and Reusable Catalytic System for the Solvent-Free Synthesis of β-Enaminones and β-Enamino Esters

A highly efficient, simple and green procedure for the synthesis of β-enaminones and β-enamino esters is described. The reaction of aromatic and aliphatic amines with β-dicarbonyl compounds using catalytic amount of silica-supported LiHSO4 (LiHSO4/SiO2) under solvent-free conditions at 80 °C affords the title compounds in high to excellent yields and in short reaction times.