A novel class of organo-nanocatalysts was fabricated by encapsulating magnetic Fe2O3@SiO2 nanoparticles with thiamine hydrochloride. Its catalytic application in the synthesis of oxygen and nitrogen containing spiro heterocycles via ultrasonication was thoroughly investigated. The synthetic protocol was found to be efficient, economical and green. The prepared catalyst was characterised by TEM, SEM, EDS, powder XRD, VSM, FT-IR, TGA, DTA, etc. Mechanistic and kinetic studies for the organic transformations were also carried out to determine the catalytic role of thiamine hydrochloride using a computational method viz. DFT: B3LYP.
