Damghan University Press Materials Chemistry Horizons 2821-2428 5 1 2026 07 27 Silica-Supported Magnetic Nanoparticles Functionalized with Phosphorus Species (Fe₃O₄@SiO₂–O–PCl₂): An Efficient and Recyclable Catalyst for the One-Pot Synthesis of Isatin-Based Imidazoles under Mild and Green Conditions 1 13 2137 10.22128/mch.2026.3386.1073 EN Somayeh Zare Department of Chemistry, Marv.C., Islamic Azad University, Marvdasht, Iran 0009-0002-9883-5649 Arezu Jamalian Department of Chemistry, Marv.C., Islamic Azad University, Marvdasht, Iran 0009-0003-4820-8599 Masoomeh Emadi Department of Chemistry, Marv.C., Islamic Azad University, Marvdasht, Iran 0000-0001-5335-4943 Journal Article 2026 07 07 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. https://mch.du.ac.ir/article_2137_08fe9447002adb5680d97974e589c1ba.pdf