Ultrasound assisted synthesis of spirooxindole analogs catalyzed by Fe3O4@PPCA NPs: Experimental, theoretical and in vitro biological studies

Abstract

In this research, a magnetically retrievable heterogenous catalyst, Fe3O4@PPCA was prepared and characterized using different techniques such as FT-IR, p-XRD, SEM, EDS, TEM, TGA and VSM. The catalytic efficiency of the nanocatalyst was evaluated in the synthesis of spirooxindole derivatives. Also, the use of ultrasonication further demonstrated the versatility of this protocol in addition to other features like simple work-up procedure, mild reaction conditions, simple catalyst recovery, short reaction time and the use of environmental friendly solvents. In vitro biological evaluation of the synthesized compounds also revealed the antitubercular activity of compound 4ce while compounds 4ga, 4gb and 4gc showed profound antioxidant activity. Computational study on the mechanistic pathway for the organic conversions was also conducted, using density functional theory (DFT), to ascertain the catalytic role of PPCA.