Fe3O4@SiO2@D-NHCS-Tr was used as an efficient catalyst in the threecomponent reaction between indole derivatives, salicylaldehyde, and active methylene compounds under solvent-free conditions to the synthesis of indol- 3-yl-4H-chromene derivatives. The features of this method include the green conditions of the reaction, easy separation, eco-friendly and cost-effectiveness of the catalyst, and high yield in short reaction times.
