Fe3O4@nSiO2@mSiO2/DBU: A Novel and Effective Basic Magnetic Nanocatalyst in the Multicomponent One Pot Synthesis of Polyhydroacridines and Polyhydroquinolines

DABCO-modified magnetic core-shell as an efficient nanocatalyst for synthesizing polyhydroquinoline derivatives

The fabrication of core-shell structured magnetic resorcinol-formaldehyde composites has garnered considerable attention within the scientific community in recent years. A key area of focus has been the immobilization of homogeneous catalysts onto the surfaces of these materials and transforming them into heterogeneous catalysts. In this study, a novel quaternary ammonium salt catalyst was synthesized by immobilizing 1,4-diazabicyclo [2.2.2] octane (DABCO) on resorcinol-formaldehyde-modified Fe3O4 nanocomposite as a support (Fe3O4@RF/Pr-DABCO). The Fe3O4@RF/Pr-DABCO nanocomposite was characterized using various physicochemical techniques, including FT-IR, VSM, SEM, XRD, and TGA. The Fe3O4@RF/Pr-DABCO nanocomposite was employed as a power nanocatalyst in the Hantzsch reaction for synthesizing polyhydroquinoline derivatives using aromatic aldehydes, ammonium acetate, dimedone and ethyl acetoacetate. Various aromatic aldehydes were used as substrates in the presence of 0.003 g of Fe3O4@RF/Pr-DABCO under solvent-free condution at 60 °C, achieving high to excellent yields (90-99%) within short reaction times (5-15 min). Furthermore, this nanocatalyst showed excellent reusability and maintained its catalytic activity for at least eight consecutive cycles without a significant decrease in efficiency. These results demonstrate the potential of the Fe3O4@RF/Pr-DABCO nanocomposite as an efficient and sustainable catalyst for the synthesis of polyhydroquinoline derivatives via the Hantzsch reaction.

Innovative synthesis of nano-magnetic bio-organocatalysts from red mud waste for green polyhydroquinoline derivatives synthesis

The imperative of transforming waste materials into valuable nanomaterials via ecological recycling has emerged as a pivotal avenue for environmental stewardship. This research contributes to the "greening" of global chemical processes by introducing a magnetic biocatalyst derived from red mud waste. Emphasizing the use of glutamic acid as the second most effective step in obtaining a green catalyst is a key focus of this work. Leveraging cost-effective materials such as FeSO4, amino acid, and Fe2O3 isolated from red mud enhances the economic viability of the synthesized catalyst. Characterization of the newly developed nano-magnetic bio-organocatalysts was conducted using advanced spectroscopic techniques, including Fourier transform infrared (FT-IR), X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), field emission scanning electron microscopy (FE-SEM), Brunauer-Emmett-Teller (BET), energy-dispersive X-ray spectroscopy (EDX), mapping, thermogravimetric analysis (TGA), and vibrating-sample magnetometers (VSM). The catalytic activity of Fe3O4@SiO2@(CH2)3@Gl was examined in the one-pot synthesis of polyhydroquinolines, showcasing short reaction times, high efficiency, ease of catalyst separation, and the potential for catalyst recycling as salient features of this work. This study pioneers the utilization of red mud waste for eco-friendly nanomaterial synthesis and underscores the economic and environmental significance of incorporating glutamic acid as a crucial element in the catalyst synthesis process.

Converting CO2 into heterocyclic compounds under accelerated performance through Fe3O4 grafted ionic liquid catalysts

Solid supported catalysts such as amines has high demand for chemical fixation of CO2 into commodity chemicals. Here, we demonstrate an accelerated platform for 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU)-ionic liquids (ILs) catalyzed CO2...