Fe₃O₄@SiO₂–NH₂core-shell nanocomposite as an efficient and green catalyst for the multi-component synthesis of highly substituted chromeno[2,3-b]pyridines in aqueous ethanol media

Abstract

(2015) Fe 3 O 4 @SiO 2 -NH 2 core-shell nanocomposite as an efficient and green catalyst for the multi-component synthesis of highly substituted chromeno [2,3-b]

Biomass Derivative Valorization Using Nano Core-Shell Magnetic Materials Based on Keggin-Heteropolyacids: Levulinic Acid Esterification Kinetic Study with N-Butanol

“…The decrease in the M S value for Fe 3 O 4 @SiO 2 can be attributed to the deposition of nonmagnetic SiO 2 on the Fe 3 O 4 surface, with the consequent lower amount of magnetite in the same sample weight [28]. However, in the Fe 3 O 4 @SiO 2 @SiO 2 /T-PA 400N2 solid ( Figure 5(a), green line), the M S value drops 30 Journal of Nanomaterials considerably to 15 emu/g, evidencing that the SiO 2 layer is much thicker, with the consequent lower amount of magnetite per unit area. In addition, a slight hysteresis loop can be observed, indicating that the catalyst has a small remanence, probably due to a significant increase in size of the catalyst particles, to a lower crystallinity, or to changes in the surface structure, as evidenced in the XRD analysis.…”

“…The applied magnetic field for these systems confirms the ferromagnetic response of these materials. It can be observed that the Fe 3 O 4 and Fe 3 O 4 @SiO 2 curves pass through the origin ( Figure 5(a), blue and red lines), giving rise to solids that do not present coercivity or remanence, whish evidences their superparamagnetic behavior [29,30]. The magnetization saturation (M S ) values for these two materials were 87 and 52 emu/g, respectively.…”

MIL‐53(Fe) Metal–Organic Frameworks (MOFs) as an Efficient and Reusable Catalyst for the One‐Pot Four‐Component Synthesis of Pyrano[2,3‐c]‐pyrazoles

“…We recently reported various synthetic methods for several biologically interesting products using nanocatalysts …”

Multi-component synthesis of spiro[diindeno[1,2-b:2′,1′-e]pyridine-11,3′-indoline]-triones using zinc terephthalate metal-organic frameworks

“…In continuation of our research on sustainable approaches for the preparation of organic compounds using nanocatalysts (38)(39)(40)(41)(42), the current article reports on the efficient synthesis of functionalized spiro…”