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 S₈ as a sulfur source in the presence of KOAc as a base.