Advances in the greener synthesis of chromopyrimidine derivatives by a multicomponent tandem oxidation process

Abstract

A hydrophilic cobalt/copper heterogeneous bimetallic catalyst named mTEG-CS-Co/Cu-Schiff-base/IL was successfully synthesized from chitosan polysaccharide. The new catalyst was investigated and confirmed using various techniques including FT-IR, FE-SEM, EDX-EDS, XRD, TEM, TGA, AFM, NMR and ICP. The catalyst exhibited powerful catalyst activity for the tandem one pot oxidative chromopyrimidine reaction from benzyl alcohols under mild conditions, utilizing air as a clean source in a green protocol. The catalyst was compatible with a wide range of benzyl alcohols, and aldehydes formed in situ, and bis-aldehydes synthesized were condensed with urea/4‑hydroxycumarin to provide favorable products in good yields for all derivatives (14 new derivatives). The presence of tri-ethylene glycol and imidazolium moieties with hydrophilic properties on the mTEG-CS-Co/Cu-Schiff-base/IL nanohybrid provides dispersion of the nanohybrid particles in water, leading to higher catalytic performance. Furthermore, the reaction exhibited several other notable features, including low catalyst loading, the ability to be recycled for up to 6 stages, high atom economy, a simple work procedure, short reaction time, utilization of an environmentally friendly nanohybrid, and the replacement of volatile and organic solvents with water solvent.

Ag/GO/Fe3O4/γ-Fe2O3 Nanocomposite for Green-Light-Driven Photocatalytic Oxidation of 5-Hydroxymethylfurfural to 5-Hydroxymethyl-2-furancarboxylic Acid

“…Wide and increasing attention to these issues requires that the chemical industries revise their activity process to use new and more accessible energies as much as possible and, on the other hand, to reduce the harmful effects on the environment . This way, a combination of environmental, health, safety, and economic considerations will be involved in the production of chemical products. − Nowadays, polymers have attracted much attention due to their wide range of applications, including antibacterial composites, solar cells, sensors, supercapacitors, microwave absorbers, self-cleaning structures, self-healing materials, and photocatalysts . Photocatalytic processes have been utilized for years as an environmental solution in industrialized countries worldwide .…”

A simple and efficient synthesis of 5-hydroxymethylfurfural from carbohydrates using acidic ionic liquid grafted on silica gel

“… 20–22 Heterogeneous catalysts modified with sulfonic acid are considered effective because of their high activity, high acid strength, ease of handling, and simple production technique. Heterogeneous catalysts are frequently recycled more readily, 23 and recovery strategies utilizing filtering or centrifugation to reduce the number of catalysts have been suggested utilizing this approach. 24 A carbonaceous catalyst containing the –SO 3 H group was utilized in the dehydration process of fructose within a DMSO medium under microwave irradiation.…”

Bifunctionalised acid-base hierarchically structured monolithic micro-/mesoreactors for continuous-flow tandem catalytic processes. A case study of cyanocinnamate synthesis

“…Various catalysts have been obtained using nanoparticles, powdered porous supports with well-de ned pore structure, i.e. SBA-15, MCM-41, MOFs, zeolites and polymers [6][7][8][9][10][11][12][13][14]. The tandem reactions usually involve at least two different catalytically active species, and often with antagonistic properties.…”