Sol–gel derived LaFeO3/SiO2 nanocomposite: synthesis, characterization and its application as a new, green and recoverable heterogeneous catalyst for the efficient acetylation of amines, alcohols and phenols

CdS/CeO2/Ag2CO3 nanocomposite as an efficient heterogeneous catalyst for Knoevenagel condensation and acetylation reactions

Knoevenagel condensation and acetylation reactions play a critical role in organic synthesis by facilitating the formation of carbon-carbon bonds and the modification of functional groups; however, limitations like low efficiency and demanding reaction conditions and time underscore the necessity for developing better techniques to enhance their practical applications. In this study, a ternary nanocomposite of CdS/CeO2/Ag2CO3 was synthesized by varying the molar ratio of CdS to CeO2/Ag2CO3 using the precipitation method. This heterogeneous catalyst was developed for Knoevenagel condensation and acetylation reactions applications. The optical properties, functional groups, crystalline structure, morphology, and surface area of the synthesized catalysts were characterized using UV-Vis-DRS, FTIR, XRD, SEM, and N2 adsorption-desorption isotherms, respectively. For the Knoevenagel condensation reaction between benzaldehyde and malononitrile, the optimal conditions were found to be the use of water as a solvent, at 10% w/w catalyst loading based on the total reagent mass, and room temperature (20 °C). Under these conditions, CdS/CeO2/Ag2CO3 with a CdS: CeO2/Ag2CO3 weight ratio of 3:1 gave high yields, 92.19 ± 0.41 in 33 min for Knoevenagel condensation and 93.8 ± 1.19 in just 3 min for the acetylation reaction. The reaction conditions were tested for different aromatic aldehydes with malononitrile, yielding high isolated products. The reusability of the CdS/CeO2/Ag2CO3 (3:1) catalyst was assessed, with only a 6.4% decrease in yield after sixth consecutive runs under optimal reaction conditions. Furthermore, the optimized catalyst, CdS/CeO2/Ag2CO3 (3:1), was evaluated for its catalytic activity in the acetylation of an aniline derivative. The structures of the synthesized products, 2-benzalidinemalononitrile and acetanilide, were confirmed by spectrometric techniques such as1H-NMR,13C-NMR, and FTIR analysis.

Visible Light-Promoted Green and Sustainable Approach for One-Pot Synthesis of 4,4'-(Arylmethylene)bis(1H-pyrazol-5-ols), In Vitro Anticancer Activity, and Molecular Docking with Covid-19 Mpro

A visible light-promoted, efficient, green, and sustainable strategy has been adopted to unlatch a new pathway toward the synthesis of a library of medicinally important 4,4'-(arylmethylene)bis(1H-pyrazol-5-ols) moieties using substituted aromatic aldehydes and sterically hindered 3-methyl-1-phenyl-2-pyrazoline-5-one in excellent yield. This reaction shows high functional group tolerance and provides a cost-effective and catalyst-free protocol for the quick synthesis of biologically active compounds from readily available substrates. Synthesized compounds were characterized by spectroscopic techniques such as IR, 1HNMR, 13CNMR, and single-crystal XRD analysis. All the synthesized compounds were evaluated for their antiproliferative activities against a panel of five different human cancer cell lines and compared with Tamoxifen using MTT assay. Compound 3m exhibited maximum antiproliferative activity and was found to be more active as compared to Tamoxifen against both the MCF-7 and MDA-MB-231 cell lines with an IC50 of 5.45 and 9.47 μM, respectively. A molecular docking study with respect to COVID-19 main protease (Mpro) (PDB ID: 6LU7) has also been carried out which shows comparatively high binding affinity of compounds 3f and 3g (-8.3 and -8.8 Kcal/mole, respectively) than few reported drugs such as ritonavir, remdesivir, ribacvirin, favipiravir, hydroxychloroquine, chloroquine, and olsaltamivir. Hence, it reveals the possibility of these compounds to be used as effective COVID-19 inhibitors.