One-Pot Multicomponent Synthesis of Chromene Analogues by HQS@CoFe2O4 Nanocatalyst

A green and efficient method has been developed for the synthesis of chromene analogues via atom-economical heterocyclization. This methodology enables ultrarapid and sustainable synthesis of heterocyclic analogues, without generating byproducts and multiple reuse cycles of the nanocatalyst. This process involves the reaction of different aldehydes, 4-hydroxycoumarin, and malononitrile in water using 8-hydroxyquinoline-5-sulfonic acid@CoFe₂O₄ (HQS@CoFe₂O₄) as a magnetic catalyst under mild reaction conditions (70 °C). The procedure offers several advantages, including operational simplicity, high yields (97%), short reaction times, and no need for laborious purification steps. The catalyst demonstrates excellent activity in aqueous media and its easy preparation and straightforward magnetic separation make it a practical and effective heterogeneous system. Notably, the catalyst can be reused multiple times with minimal loss of performance. The synthesized chromene analogues were characterized by melting point, IR, and ¹H NMR spectroscopy, confirming their successful formation.

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