https://mch.du.ac.ir/ Materials Chemistry Horizons en daily 1 Mon, 27 Jul 2026 00:00:00 +0330 Mon, 27 Jul 2026 00:00:00 +0330 https://mch.du.ac.ir/article_2137.html The synthesis, characterization, and catalytic activity of a novel magnetic nanocatalyst based on phosphorus-functionalized silica-coated iron oxide nanoparticles (Fe₃O₄@SiO₂–O–PCl₂) are described. The prepared nanocatalyst was characterized using FTIR, XRD, VSM, TGA/DTG, FESEM, SEM–EDX, and mapping techniques. Its catalytic performance was evaluated in a one-pot three-component reaction of aromatic aldehydes, isatin, and ammonium acetate to afford a series of substituted 2-phenyl-3,4-dihydroimidazo[4,5-b]indoles with yields of up to 90%. The method offers several advantages, including mild reaction conditions, short reaction times (1 h), high product yields, and excellent catalyst reusability (up to 5 cycles with only a slight loss of activity). The magnetic nature of the catalyst enables facile recovery using an external magnet, making this protocol economically and environmentally benign.