Novel Cu(0)-Fe3O4@SiO2/NH(2)cel as an Efficient and Sustainable Magnetic Catalyst for the Synthesis of 1,4-Disubstituted-1,2,3-triazoles and 2-Substituted-Benzothiazoles via One-Pot Strategy in Aqueous Media

摘要

A novel, air stable, water dispersible and efficient magnetic catalyst based on copper nanoparticles onto ethylene diamine functionalized inorganic/organic composite [Cu(0)-Fe3O4@SiO2/NH(2)cel] has been prepared. Functionalization of inorganic/organic composite by ethylene diamine imparts desirable chemical functionality and enables the generation of active sites for the immobilization of Cu(0) nanoparticles. The novel catalyst system has been well characterized by various techniques like FTIR, TGA, XRD, SEM, HRTEM, EDX, ICP-AES, UV-Vis and VSM. Further, Cu(0)-Fe3O4@SiO2/NH(2)cel opens up a new avenue to introduce a very useful and efficient catalytic system for the one-pot synthesis of 1,4-disubstituted-1,2,3-triazoles via 1,3-dipolar cycloaddition of terminal acetylenes to azides, generated in situ from anilines in water at room temperature, and one-pot three component reaction of 2-iodoaniline, aldehyde and thiourea as sulphur source for the synthesis of 2-substituted-benzothiazole derivatives in water. The novel heterogeneous magnetic catalyst offers recyclability without significant deterioration in catalytic activity and can be easily recovered using an external magnet, thus making it eco-friendly and economical to perform the desired transformations.