Zn[L-proline]2 as an Efficient Catalyst for the Synthesis of Dihydro Pyrano Thiazole Derivatives via Cycloaddition Reaction in Aqueous Medium

: In the current study, a zinc-linked amino acid complex was successfully synthesized as an efficient and recoverable catalyst for the synthesis of dihydro pyrano thiazole derivatives via the reaction of an aromatic aldehyde with malononitrile and rhodanine in one-pot, three-component reaction under green conditions. The structures of the new compounds were elucidated by elemental and spectral analyses. Environmental friendliness, low cost, operational simplicity, extensive reusability and applicability, and easy recovery of the catalyst using simple methods are the critical features of this methodology. Moreover, a series of dihydro pyrano thiazole derivatives were synthesized. This new procedure has presented remarkable advantages in terms of safety, simplicity, stability, mild conditions, short reaction time, excellent yields, and high purity without using any hazardous solvents.