The preparation of polyvinyl imidazole-functionalized magnetic biochar decorated by silver nanoparticles as an efficient catalyst for the synthesis of spiro-2-Amino-4H-pyran compounds

Abstract

The silver nanoparticle was synthesized by developing poly (1-vinylimidazole) on the surface of magnetized biochar (the stem and roots of Spear Thistle) (biochar/Fe3O4/PVIm/Ag). This nanocomposite was characterized by Fourier-transformed infrared spectroscopy (FTIR), powder X-ray diffraction (XRD), vibrating sample magnetometer (VSM), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM–EDS), and transmission electron microscopy (TEM). The SEM and TEM images of the nanocatalyst, biochar/Fe3O4/PVIm/Ag-NPs, confirmed the observation of microscopic sheets of biochar. The catalytic activity of these Ag NPs was tested via multicomponent reaction plus reusing to successful formation of 2-amino-4H-pyran and functionalized spirochromen derivatives. The prepared nanocatalyst was easily separated by an external magnet and reused in repeating coupling reaction cycles four times without remarkable activity loss. The catalyst showed great efficiency and reusability, thus making it an ideal candidate for catalytic purposes in several organic transformations.

Copper Immobilized on Modified LDHs as a Novel Efficient Catalytic System for Three-Component Synthesis of Pyrano[2,3-d]pyrimidine and pyrazolo[4′,3′:5,6]pyrano[2,3-d]pyrimidine Derivatives

“…The melting points of the samples were determined using the Electrothermal 9200 device and have not been modified. 1 H and 13 CNMR spectra of the products were taken using the Varian INOVA 500 MHz device. The FTIR spectrum of the samples was obtained using KBr tablets and the PerkinElmer GX FTIR device.…”

“…Also, the peaks of 517, 574, and 1384 cm −1 are related to copper nitrate, indicating successful placement of copper nitrate on the catalyst. The 1 HNMR and 13 CNMR spectra of ligand N1,N4-bis(4,6diamino-1,3,5-triazin-2-yl)benzene-1,4-disulfonamide (NDBD) are shown in Figure 2. Part (a) corresponds to the 1 HNMR of NDBD in DMSO solvent.…”

“…The single protons of the benzene ring with an integral of 1 appear at δ 7.27−7.33 and δ 8.39, respectively, as a tribrach and a monobranch. Part (b) is the 13 C NMR spectrum of the NDBD ligand. The peak at δ 147.4 is related to two carbons of the benzene ring connected to the SO 2 group.…”

“…Multicomponent reactions (MCRs) constitute one of the most important fields in organic synthesis, widely employed for their energy efficiency, high speed, ease, and cost-effectiveness . In recent years, significant advances have been made in multicomponent reactions, with ongoing efforts focused on MCRs in the presence of new catalysts. − Pyrano­[2,3- d ]­pyrimidines and their derivatives are heterocycle compounds containing nitrogen, utilized for their extraordinary medicinal and medical properties, including anticancer, antibacterial, antiviral, antihypertensive, antiallergic, anticoagulant, and antibronchitis effects . Due to the myriad applications, the design of new catalysts for their synthesis is paramount.…”

Hyperbranched 5-sulfosalicylic acid-TDI-chitosan decorated by Fe3O4 nanoparticles: a highly efficient solid acid organocatalyst for the synthesis of quinazoline derivatives under green conditions

“…Among these, heterogeneous catalytic systems and associated magnetic nanoparticles (MNP) have received great attraction from scientists recently, since they have unique properties including high thermal stability, structural diversity, easy modi cations, strong absorption, low toxicity, and a variety of advantages such as ease of separation and reusability [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39] . Moreover, the designed-procedures for the preparation of nanomaterials including magnetic nanoparticles and their catalytic activities are entirely veri ed in the eld of greener and atom-economic reactions especially multicomponent reactions (MCRs) 12,21,[40][41][42][43][44][45][46][47] .This impact would be more deepened if the naturally occurring, renewable and biodegradable biopolymers such as chitosan, cellulose, alginate, etc be used in the structure of magnetic nanomaterials 12,23,34,[48][49][50] .…”