Facile and sustainable approach to the synthesis of 4H-pyrans using efficient pyrazolium ionic liquids functionalized silica nanocomposites catalysts

The development of sustainable and multifunctional catalytic systems is of paramount importance in advancing green synthetic methodologies. In this study, a type of novel functional ionic liquids functionalized silica nanocomposites, based on a pyrazolium core, were strategically designed and synthesized. The catalytic efficacy of these nanocomposites was systematically investigated in the one‐pot three-component reaction of aldehydes and malononitrile with 1,3-cyclohexanedione or ethyl acetoacetate, targeting the synthesis of 4H-pyrans. Among the evaluated systems, SiO 2 @PILAlO 2 exhibited superior catalytic activity, affording 89–98% isolated product yields under optimized green conditions using water as the reaction medium. Notably, the catalyst SiO 2 @PILAlO 2 exhibited excellent recyclability, retaining catalytic performance over six successive cycles without observable loss in activity. Compared to conventional catalysts, this method offers significantly shorter reaction times, higher yields, operation at room temperature, and facile recovery with reusability up to six cycles. Thus, this approach provides a practical and eco-friendly for the synthesis of 4H-pyran derivatives.