IIn this work, a new core-shell magnetic silica functionalized with 3,4-diaminobenzoic acid nanocatalyst (Fe3O4@SiO2@PTS-DABA) was successfully prepared and characterized using different spectroscopic methods or techniques including FT-IR, FE-SEM, VSM, XRD,...

In this work, D-(–)-α-phenylglycine (APG)-functionalized magnetic nanocatalyst (Fe3O4@SiO2@PTS-APG) was designed and successfully prepared in order to implement the principles of green chemistry for the synthesis of polyhydroquinoline (PHQ) and 1,4-dihydropyridine (1,4-DHP) derivatives under ultrasonic irradiation in EtOH. After preparing of the nanocatalyst, its structure was confirmed by different spectroscopic methods or techniques including Fourier transform infrared (FTIR) spectroscopy, energy-dispersive X-ray spectroscopy (EDS), field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), vibrating sample magnetometer (VSM) and thermal gravimetric analysis (TGA). The performance of Fe3O4@SiO2@PTS-APG nanomaterial, as a heterogeneous catalyst for the Hantzsch condensation, was examined under ultrasonic irradiation and various conditions. The yield of products was controlled under various conditions to reach more than 84% in just 10 min, which indicates the high performance of the nanocatalyst along with the synergistic effect of ultrasonic irradiation. The structure of the products was identified by melting point as well as FTIR and 1H NMR spectroscopic methods. The Fe3O4@SiO2@PTS-APG nanocatalyst is easily prepared from commercially available, lower toxic and thermally stable precursors through a cost-effective, highly efficient and environmentally friendly procedure. The advantages of this method include simplicity of the operation, reaction under mild conditions, the use of an environmentally benign irradiation source, obtaining pure products with high efficiency in short reaction times without using a tedious path, which all of them address important green chemistry principles. Finally, a reasonable mechanism is proposed for the preparation of polyhydroquinoline (PHQ) and 1,4-dihydropyridine (1,4-DHP) derivatives in the presence of Fe3O4@SiO2@PTS-APG bifunctional magnetic nanocatalyst.

In this work, D-(−)-α-phenylglycine (APG)-functionalized magnetic nanocatalyst (Fe3O4@SiO2@PTS-APG) was designed and successfully prepared in order to implement the protocols of green chemistry for the synthesis of polyhydroquinoline (PHQ) and 1,4-dihydropyridine (1,4-DHP) derivatives under ultrasonic radiation in EtOH. After preparing the nanocatalyst and confirming its structure by different spectroscopic methods or techniques including Fourier transform infrared (FT-IR) spectroscopy, energy-dispersive X-ray spectroscopy (EDS), field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), vibrating sample magnetometer (VSM) and thermal gravimetric analysis (TGA). Its performance under ultrasonic radiation and various conditions were examined. The yield of target derivatives was controlled under various conditions and it was found that it reaches more than 80% in just 10 min, which indicates the high performance of the nanocatalyst along with the synergistic effect of ultrasonic radiation. The structure of the products was identified by melting point as well as FT-IR and 1H NMR spectroscopic methods. The Fe3O4@SiO2@PTS-APG nanocatalyst is easily prepared from commercially available, lower toxicity and thermally stable precursors through a cost-effective, highly efficient and environmentally friendly procedure. The advantages of this method include simplicity of operation, reaction under mild conditions, use of environmental radiation sources, obtaining pure products with high efficiency in the shortest time without using a tedious path which is all in the shadow of green chemistry. Finally, a reasonable mechanism is proposed for the preparation of polyhydroquinoline (PHQ) and 1,4-dihydropyridine (1,4-DHP) derivatives in the presence of Fe3O4@SiO2@PTS-APG bifunctional magnetic nanocatalyst.