Fe 3 O 4 @SiO 2 @propyl-AMP/Co: A new catalyst for the synthesis of benzopyrans

Among the multicomponent reaction, synthesis of benzopyrans is one of the most important and vital reactions with remarkable industrial significance. This study describes the design/preparation of an ecofriendly recyclable catalyst for this reaction. For this purpose, a new functionalized magnetic nanocatalyst was designed through the reaction between 2-aminomethylpyridine (AMP) and Fe 3 O 4 @SiO 2 @propyl. Next, the as-prepared nanocatalyst was decorated via cobalt ions to synthesize Fe 3 O 4 @SiO 2 @propyl-AMP/Co. The as-synthesized materials were properly characterized through ICP-OES, TG-DTA, FT-IR, EDX, XRD, SEM, and TEM. This nanocatalyst was used in the synthesis of benzopyrans and showed its application in a diverse range of different functional groups with good efficiency. The melting point test, 1 H-NMR and 13 C-NMR were taken from the reaction products, showing the successful performance of this catalyst. The remarkable characteristics of this catalytic system are the great turnover number (TON), considerably high selectivity, good turnover frequency (TOF), high yield, fast and almost complete conversion of products, and facile and convenient separation of catalyst and product. According to the obtained results, the highest yields in the shortest reaction time were attained using Fe 3 O 4 @SiO 2 @propyl-AMP/Co. (c) 2023 Elsevier B.V. All rights reserved.