Ethylenediamine-functionalized magnetic Fe₃O₄@SiO₂ nanoparticles: cooperative trifunctional catalysis for selective synthesis of nitroalkenes

Abstract

A magnetically separable trifunctional nanocatalyst Fe 3 O 4 @SiO 2 -NH 2 was synthesized and characterized by TEM, FT-IR, XRD, TGA, and EA. The designed nanocatalyst was found to be highly active for selective synthesis of nitroalkenes with nitromethane and aromatic aldehyde through cooperative trifunctional catalysis of primary amine, secondary amine and Si-OH groups on the surface of catalyst. Under the optimized conditions, various representative substrates were extended to obtain the corresponding products in a moderate or excellent yield. After reaction, the trifunctional nanocatalyst was easily recovered and recycled by applying an external magnet. In addition, a possible cooperative trifunctional catalysis mechanism was also proposed.

Encapsulation of patchouli (Pogostemon cablin Benth), nutmeg (Myristica fragrans), and citronella (Cymbopogon nardus) essential oil using a combination of coating materials with complex coacervation method

“…The absorbance of the supernatant was measured using a UV-Vis spectrophotometer with a maximum wavelength. The blank measurement will be carried out as a correction [12]. The following equation will calculate the encapsulation efficiency: Encapsulation Efficiency (%) = total oil − surface oil total oil × 100%…”

Architectured Fe3Pd2(OH)2[picolinic acid]8(H2O)4 Hybrid Nanorods: A Remarkably Reusable and Robust Heterogeneous Catalyst for Suzuki–Miyaura and Mizoroki–Heck Cross-Coupling Reactions

“…Suzuki–Miyaura and Mizoroki–Heck cross-coupling reactions in solution are among the most efficient and useful cross carbon–carbon coupling reactions in organic synthesis. , They allow the highly selective joining of organic moieties A and B into A–B while avoiding the formation of A–A or B–B. Nowadays, the catalysts of Suzuki–Miyaura and Mizoroki–Heck reactions have been an ongoing research hot-spot. − Recently, heterogeneous catalysts have attracted much attention in the catalytic reaction due to the simple removal from the reaction mixture by filtration or centrifugation and its reuse following appropriate washing processes . The fabrication of multicomponent catalysts, such as metal–metal hydroxide and metal-oxide-based catalysts, has an effective method for preparing heterogeneous catalysts with high activities. − In particular, supported heterogeneous Pd-catalyzed Suzuki–Miyaura and Mizoroki–Heck, commonly used as immobilized Pd nanoparticles on silica, other inorganic supports, as well as polymeric materials, have been efficiently used in numerous procedures for the construction of C–C bonds. − Despite their superb catalytic performance, they suffer from high cost and low abundance in the Earth’s crust.…”