In this study, periodic acid-functionalized magnetic support (Fe3O4@TiO2-H5IO6) as a new, benign and recyclable nanocatalyst was prepared by anchoring / periodic acid onto TiO2-coated nano-Fe3O4. This catalyst was applied to achieve a high-efficiency, low-cost and eco-friendly approach for synthesizing 4-substituted-1,5-benzodiazepines with the multicomponent reactions of aromatic aldehydes, o-phenylenediamine, and dimedone. The / periodic acid group on Fe3O4@TiO2 possesses both Lewis and Brønsted acidity, which is responsible for the high catalyst activity. The obtained results show that the catalyst performance has been acceptable in the presented research. / The catalyst could be recovered and reused up to six times without any notable decrease in its activity.

Fatemeh Ahmadzadeh, Bahador Karami, Mahnaz Farahi and Jamileh Etemad