An Attractive Route to Benzothiazole or Benzoxazole-Sulfide Aryls: CuFe₂O₄ NPs as a Highly Efficient Recoverable Nanocatalyst for Three-Component Coupling Reaction of Benzoazoles with Aryl Iodides and Sulfur Source in ChCl-Urea

Magnetic nanoparticles are efficient catalytic systems for various reactions because of their high efficiency and easy separation. Amongst magnetic nanoparticles, copper ferrite (CuFe2O4 NPs) is one of the different types of ferrites, which is widely used in catalytic reactions because of its magnetic properties. On the other hand, deep eutectic solvents (DESs) consisting of a hydrogen bond acceptor component and a hydrogen bond donor component have recently attracted the attention of many researchers as green solvents. ChCl-urea is considered a green DES that has been reported several times to carry out chemical reactions. In recent years, research on the synthesis of 2-thioaryl-benzothiazoles and 2-thioaryl-benzoxazoles (compounds containing C-S aryls and benzothiazoles and benzoxazoles scaffolds) has become an attractive challenge in organic chemistry. In this research, we report the synthesis of 2-thio-benzothiazoles and 2-thioaryl-benzoxazoles by CuFe2O4 NPs in ChCl-urea as an efficient nanocatalyst. These compounds were synthesized via a one-pot, three-component coupling reaction of benzoxazoles or benzothiazoles with aryl iodides and S-8 as a sulfur source in the presence of KOAc as a base.