Deep eutectic solvent-catalyzed arylation of benzoxazoles with aromatic aldehydes

Abstract

A novel and efficient methodology for the arylation of benzoxazoles with aromatic aldehydes catalyzed by deep eutectic solvent has been developed. The reaction smoothly proceeded with a wide range of substrates to give the desired products in high yields within short reaction time. Deep eutectic solvents are easily recovered and reused without significant loss of catalytic activity. Results and discussion Preparation and characterization of [ZnCl 2 ][ethylene glycol] 4DESs were synthesized by mixing zinc chloride and ethylene glycol (HBDs) at a dened molar ratio (1 : 4) and heating at 120 C for 1 h at atmospheric pressure under constant magnetic stirring until a homogeneous liquid was formed. The charge delocalization which occurs through hydrogen bonding between the halide anion and ethylene glycol is responsible for the decrease in the T m of the mixture. 52,53

An efficient multicomponent synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles catalyzed by a magnetic nanoparticle supported Lewis acidic deep eutectic solvent

“…3,4 The stable and efficient LADESs can afford the desired products in high yield and selectivity against the conventional metal halide catalysts. [5][6][7][8][9][10][11] However, some drawbacks such as the use of a large amount of LADESs, difficulty in catalyst recovery and product separation, which can cause environmental pollution and a high-cost to the procedure, limit their application in industrial processes. The development of heterogeneous DES catalysts in organic reactions has become a signicant area of research due to the advantages of these materials over traditional homogeneous DESs such as easy product separation, efficient recovery and reusability, and workup simplicity.…”

Synthesis of a new series of 2-hydroxy-5-iodo-N’-(1-arylethylidene)benzohydrazides using a deep eutectic solvent as solvent/catalyst under sonication

“…Recently, DESs have been applied to many applications such as electrochemistry, gas adsorption, extraction [16], metal processing, catalysis, drug solubilization vehicles [17], fuel [18], and biodiesel [19]. However, a few studies were reported for using DES as a catalyst or solvent in chemical reactions [2, 20, 21, 22, 23, 24, 25].…”

Peering into the Formation of Template-Free Hierarchical Flowerlike Nanostructures of SrTiO3

“…The IR features shown in Figure 7 a display the vibration bands at 1084 and 1030 cm –1 , related to the C–C–O vibration of surface-adsorbed EG. 49 , 50 The bands at 1650 and 1460 cm –1 are related to the C=O and pyrrolidinyl groups from the PVP chains. 51 A low intensity band can also be observed for all samples at 856 cm –1 .…”