A new green method for synthesis of some novel derivatives uses Core-shell Fe3O4@SiO2 nanoparticles as a reusable catalyst

The preparation and the use of magnetic nanoparticles (MNPs) in organic synthesis has become a subject of intense investigation. which offer advantages in clean and sustainable chemistry as they can be non-toxic, readily accessible, and reusable. Additionally, the activity and selectivity of magnetic catalysts can be manipulated by its surface modification.[1] Thiopyran and indole core skeleton are important syntonic of heterocyclic compounds and are important class of structural motifs present in many natural products [2]. Thiopyrano sulfur compounds as well as have a many biological activity such as anti-bacterial, anti-hyperplasia and anti-cancer activities [3,4]. In this regard, we are reported a facile, green and high efficiency methodology for synthesis of some novel dihydrothiopyran derivatives from indolin-2-thion 1, malononitrile 2 and aldehyde 3. (Figure1) This catalytic system can be easily recovered and reused for at least three times without significant loss of its activity.