Visible Light‐Mediated Multicomponent Synthesis of Spirooxindole‐Linked Fused Pyrans: An Eco‐Friendly One‐Pot Strategy

Abstract A green and efficient method for the preparation of spirooxindole‐linked fused pyrans has been developed utilizing a catalyst‐free visible‐light‐driven one‐pot multicomponent reaction strategy. The reaction was performed in a water and ethanol mixture, using the combination of isatin, malononitrile, and cyclic 1,3‐dicarbonyls such as 4‐hydroxy‐1‐methyl‐2(1 H )‐quinolone, 4‐hydroxycoumarin, 4‐hydroxythiocoumarin, or barbituric acid derivatives. This catalyst‐free, environmentally friendly, visible‐light‐driven, and room temperature method is a valuable addition to the synthetic toolbox for constructing complex heterocyclic scaffolds under one‐pot conditions. It holds promise for future applications in medicinal chemistry and drug discovery.