Superparamagnetic CuFeO₂ Nanoparticles in Deep Eutectic Solvent: an Efficient and Recyclable Catalytic System for the Synthesis of Imidazo[1,2‐a]pyridines

Abstract

Superparamagnetic CuFeO2 nanoparticles were prepared and characterized by XRD, SEM, TEM, FRIR spectroscopy, and vibrating sample magnetometry techniques. The catalytic activity of CuFeO2 nanoparticles was investigated in the one‐pot, three‐component reaction of 2‐aminopyridines, aldehydes, and alkynes using citric acid–dimethylurea melt as a green solvent. An array of imidazo[1,2‐a]pyridines were obtained in good to excellent yields. The catalytic system can be successfully reused six times with keeping its catalytic performance.

Deep Eutectic Solvents: The Organic Reaction Medium of the Century

“…Following this methodology, both catalyst and DES could be reused six times without any detrimental effect on the yield. [123] Scheme 47. Multicomponent synthesis of imidazo[1,2-a]pyridines.…”

Choline chloride and itaconic acid-based deep eutectic solvent as an efficient and reusable medium for the preparation of 13-aryl-5H-dibenzo[b,i]xanthene-5,7,12,14(13H)-tetraones

“…The ease of preparation, availability, cost effectiveness, stability, less toxicity, and biodegradability make these DESs versatile alternatives to ionic liquids. In view of some previous works [26][27][28][29][30][31][32][33][34][35][36][37][38] and our recent research programme on the development of novel and environmentally benign synthetic methodologies [39][40][41][42][43][44][45], herein we report ChCl/itaconic acid as reaction medium and catalyst for the synthesis of 13-aryl-5H-dibenzo[b,i]xanthene-5,7,12,14(13H)-tetraones by condensation of 2-hydroxynaphthalene-1,4-dione with aldehydes (Scheme 1).…”

Mesoporous silica SBA‐15 functionalized with acidic deep eutectic solvent: A highly active heterogeneous N‐formylation catalyst under solvent‐free conditions

“…Moreover, unlike ionic liquids, these green solvents do not require a preliminary purification step since one only has to mix natural and readily available starting materials. [36][37][38][39][40][41][42] Based on the above information, our research group has been engaged mainly on the development of environmentally friendly organic synthesis in green reaction media such as water and DESs. [43][44][45] In our development efforts towards this important class of DESs, herein we report an alternative, recyclable, mild and highly effective catalytic system based DES that immobilized on nanoporous silica SBA-15 for the N-formylation of amine derivatives with formic acid under solvent-free conditions.…”