Synthesis and characterization of the novel diamine‐functionalized Fe3O4@SiO2 nanocatalyst and its application for one‐pot three‐component synthesis of chromenes

Fe3O4@SiO2@propyltriethoxysilane@o‐phenylendiamine as an environmentally‐benign functionalized silica‐coated magnetic organometallic nanomaterial has been synthesized and characterized by Fourier transforms infrared (FT‐IR) spectroscopy, scanning electron microscopy (SEM) images and energy dispersive X‐ray (EDX) and vibrating sample magnetometer (VSM) analyses. Then, its catalytic activity was investigated for the one‐pot three‐component condensation reaction between dimedone, malononitrile and various substituted aromatic aldehydes to afford the corresponding 2‐amino‐4H‐chromene derivatives under mild reaction conditions. This nanocatalyst can be easily recovered from the reaction mixture by using a magnet and reused for at least five times without significant decrease in catalytic activity. A new and environmentally‐benign OPDA‐functionalized silica‐coated magnetic heterogeneous catalyst have been synthesized and its activity was investigated for the one‐pot three‐component condensation reaction between aromatic aldehydes, dimedone and malononitrile to afford the corresponding chromene derivatives under mild reaction conditions.