Zn[(L)-proline], as a recyclable and green catalyst for efficient and one-pot three-component synthesis of 1,4-Dihydro- pyridines under solvent-free and microwave irradiation conditions

Abstract

Zn[(L)-proline], was faund to be efficient, green, and recyclable catalyst for the synthesis of 1,4-dihydropyridines by condensation reaction of aldehydes, ethyl acetoacetate, and ammonium acetate in high to excellent yields under solvent-free and microwave irradiation conditions. The present methodology offers several advantages, such as a simple procedure with an easy workup, high yields, and the absence of any volatile and hazardous organic solvent. Morever, the catalyst can be easily recovered and reused at least three time with only slight reduction in its catalytic activity.