Development of magnetically retrievable spinel nanoferrites as efficient catalysts for aminolysis of epoxides with amines

Magnetically separable spinel nanoferrites (MFe2O4; M = Co, Ni, Cu and Zn) have been used as proficient catalysts for epoxide ring opening with amines. To study the effect of synthetic methodology on the catalytic activity, all the spinel nanoferrites were fabricated using three different techniques i.e sol-gel, hydrothermal and micro-emulsion method. The synthesized samples exhibited small particle size and high surface area values along with sufficiently magnetic nature to be used as magnetically separable heterogeneous green catalysts. The commencement of the important epoxide ring opening reaction via a green approach i.e by using magnetically recyclable nanoferrites under solvent free conditions in a very short reaction time (4-25 min), is the main highlight of the present work. Best catalytic results for epoxide ring opening were obtained with CoFe2O4 nanoparticles prepared using hydrothermal method which resulted in 100% conversion of the reactants to the corresponding amino alcohol.