Synthesis and characterization of a novel functionalized magnetic Fe3O4 as a nanocatalyst for synthesis and antibacterial activities of 2-amino-3-phenylsulfonyl-4-aryl-4H-benzo[h]chromens derivatives and theoretical study on the mechanism using a DFT Method

摘要

In this work, a new organic-inorganic hybrid heterogeneous and efficient magnetic nanocatalyst was fabricated with 4-aminopyridine (AP)-functionalized Fe3O4 (Fe3O4@AP) nanoparticles. Then, prepared nanocatalyst was characterized by FT-IR, XRD, TGA, TEM and SEM techniques. The catalytic activity of the magnetic nanocatalyst was employed to synthesis of 2-amino-3-phenylsulfonyl-4-aryl-4H-benzo[h]chromens derivatives through one-pot three-component reactions of alpha-naphtol with aromatic aldehyde and (phenylsulfonyl) acetonitrile under ethanol solvent at 60 degrees C conditions. The synthetic compounds exert moderate activity against both Gram-positive and Gram-negative bacteria and their effectiveness is higher against Bacillus subtilis. This green nanocatalytic procedure has advantages such as excellent recoverability, short reaction time, simple and comfortable procedure, ready separation with an external magnet with no considerable loss of its catalytic efficiency, high yields and biocompatibility. The mechanism of the reaction investigated by density functional theory-based modelling is also reported. Results of this study show that the reaction has four TS structure. For TS1, mode using GaussView software clearly shows the animation of the imaginary frequency with a vibration frequency at - 874.23 cm(-1) and TS2 at - 1058.67 cm(-1). Also, the transition state for TS3 and TS4 shows an imaginary frequency with a vibration frequency at - 1044.65 cm(-1) and at - 815.11 cm(-1). This study aims at giving insight into the mechanism of the 2-amino-3-phenylsulfonyl-4-aryl-4H-benzo[h]chromens reaction in the presence of nanocatalyst of Fe3O4@AP.