Magnetically Recyclable CoFe2O4@SiO2/Co (III) Salen complex as a Heterogeneous Nanocatalyst for the synthesis of di-indolyloxindole.

Di-indolyloxindoles are heterocyclic compounds with biological properties such as anti-inflammatory, antibacterial and laxative effects [1]. From economic and environmental viewpoints, developing novel, efficient and inexpensive catalytic system for the synthesis of heterocyclic compounds specially di-indolyloxindoles isstill an important goal in chemistry. Heterogeneous catalysts have been extensively studied as a powerful and extremely versatile synthetic tool to afford selectively heterocyclic compounds [2]. In this study, CoFe2O4@SiO2/Co (III) Salen complex was synthesized and used for the synthesis of di-indolyloxindoles in water at 80 ℃. The results showed that the corresponding products were syntrhesized in good to excellent yields. This catalyst exhibits good reusability, efficiency, and complies with the concept of green chemistry.