Potassium-Exchanged Zirconium Hydrogen Phosphate [-Zr(KPO4)2]-Catalyzed Synthesis of 2-Amino-4H-pyran Derivatives under Solvent-Free Conditions

A high-yielding, one-pot, three-component synthesis of functionalized 2-amino-4H-pyrans from -dicarbonyl compounds, activated cyanomethylene compounds, and aldehydes, mediated by potassium-exchanged zirconium hydrogen phosphate [-Zr(KPO4)(2)], is reported. The protocol shows excellent versatility, as it can be applied to aromatic, aliphatic, or ,-unsaturated aldehydes under solvent-free conditions.