Arup Dutta and Rishanlang Nongkhlaw
A new class of organo-nanocatalysts was fabricated by encapsulating magnetic Fe2O3@SiO2 nanoparticles with thiamine hydrochloride. The prepared catalyst was characterized by various analytical techniques viz., FT-IR, TGA, TEM, SEM, EDX, Powder XRD and VSM and its catalytic activity was investigated for the synthesis of spirooxindole derivatives. Utilizing the ferromagnetic nature of core Fe2O3 nanoparticles, the encapsulated catalyst could be easily retrieved from the reaction mixture after completion of the reaction by using an external magnet. The catalyst was reused up to six runs with remarkable catalytic activity. The main advantages of this synthetic approach lie in its operational simplicity, cost effectiveness, higher yields, easy catalyst recyclability and reusability, eco-friendly procedures and shorter reaction times. Mechanistic studies for the organic transformations were also carried out to determine. The catalytic role of thiamine hydrochloride using a computational method viz. DFT: B3LYP. Also, the anthelminthic assay of the synthesized spirooxindoles was evaluated against raillietina sp and syphaciaobvelata and the results showed profound anthelmintic activities.
