چكيده فارسي :
During the past decade, a great deal of attention has been paid to developing greener chemical processes and synthetic methods. Catalysts bound to inorganic solids are widely used for organic transformations due to environmental and economical considerations [1]. Nanoparticles supported on a metal oxide as an inorganic solid, in particular magnetic nanoparticles (MNPs), have been extensively studied in the field of chemical catalysis, environmental protection, sensors, magnetic storage media, and clinical diagnosis treatments. MNPs have great potential in view of their recovery, since the magnetic separation of MNPs from the reaction mixture with an external magnet is simpler and more efficient than conventional separation with filtration or centrifugation. On the other hand, MNPs are accessible from inexpensive materials and can be easily supported organic and inorganic materials. Recently, MNP-supported-copper ions have been used extensively in organic transformations.[2]. In this work, a new magnetically recoverable nanocatalyst was developed by covalent binding of a ligand, 2-amino banzhydrazide and 2-hydroxy naphtaldehyde on the surface of silica coated magnetite nanoparticles (SCMNPs) and followed complexation with CuCl2.4H2O. Characterization of the prepared nanocatalyst was performed with different physicochemical methods such as FT-IR, TCP-AES, VSM, SEM EDS and TGA analyses. Finally, catalytic activity of the prepared nanocatalyst was examined in the preparation of 2-amino-4H-benzo[h]chromene derivetives through a one-pot, three component reactions of 1-naphthol, various aldehydes and malononitrile. The synthesized nanocatalyst was efficient. The benefits of this protocol are simple workup procedure, short reaction time and high yields of products. The immobilized complex was reused for several times without meaningful loss in catalytic performance.
