GO‐TiO2 Nanocomposite: An Efficient Catalyst for the Conventional and Ultrasonically Mediated Multicomponent Synthesis of 2, 4, 5‐Trisubstituted Imidazole Derivatives**

Abstract

AbstractA flexible, reliable, and effective method for the synthesis of a wide variety of highly functionalized 2, 4, 5‐trisubstituted imidazole derivatives are reported. It involves a one‐pot, multicomponent process using a variety of aldehydes, ammonium acetate, and benzil /benzoin in the presence of non‐toxic, readily accessible, affordable, reusable and unexplored catalysts, GO‐TiO2. This one‐pot synthesis method has numerous benefits, including benign reaction conditions, a quick reaction time, low catalyst loading, efficient productivity with better atom economy and functional group tolerance, which makes this methodology realistic. TiO2 is known for its excellent catalytic activity for many organic reactions, however GO‐TiO2 nanocomposite is yet to be explored in the field of heterocyclic synthesis. In the present work GO‐TiO2 nanocomposite has been introduced as a catalyst for the synthesis of imidazole derivatives and among the TiO2 and GO‐TiO2 catalysts, GO‐TiO2 exhibited better catalytic efficiency and provided great substrate scope with α‐hydroxy ketone (benzoin) as well as 1, 2‐diketone (benzil). Both the conventional method as well as ultrasonically mediated method has been adopted to find out the best possible methodology for the synthesis of 2, 4, 5‐trisubstituted imidazole derivatives.