A new copper(II) Schiff base complex immobilized on silica-coated nanomagnetic Fe 3 O 4 was synthesized from acetylacetonate (acac) and 2aminothiophenol (ATP). The newly synthesized nanocatalyst, Fe 3 O 4 @SiO 2acac-2ATP-Cu(II), was structurally characterized using several analytical techniques. The catalytic activity of the Fe 3 O 4 @SiO 2 -acac-2ATP-Cu(II) nanoparticles was investigated for the synthesis of pyrano[2,3-b]pyridine derivatives from the one-pot three-component reaction of aldehydes, malononitrile and 3-cyano-6-hydroxy-4-methylpyridin-2(1H)-one. A high catalytic performance was exhibited by this nanocatalyst under solvent-free conditions and excellent yields of the products were achieved in reasonably short reaction times. The nanoparticles could be easily separated from the reaction mixture simply by magnetic decantation and reused for several consecutive runs without significant loss of catalytic activity. KEYWORDS acac-2ATP Schiff base-Cu(II) complex, Fe 3 O 4 -immobilized Schiff base copper complex, nanomagnetic Fe 3 O 4 , nanoparticle, pyranopyridine

A novel Cu (II) Schiff-base complex immobilized on core-shell magnetic Fe 3 O 4 nanoparticles (Fe 3 O 4 @SPNC) was successfully designed and synthesized. The structural features of these nanoparticles were studied and confirmed by using various techniques including FT-IR spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive Xray spectroscopy (EDS), vibrating sample magnetometer (VSM), X-Ray diffraction (XRD), wavelength dispersive X-ray spectroscopy (WDX), and inductively coupled plasma (ICP). These newly synthesized nanoparticles have been used as efficient heterogeneous catalytic system for one-pot multicomponent synthesis of new pyrano[2,3-b]pyridine-3-carboxamide derivatives. Notably, the catalyst could be easily separated from the reaction mixture by using an external magnet and reused for several successive reaction runs with no significant loss of activity or copper leaching. The present protocol benefits from a hitherto unreported MNPs-immobilized Cu (II) Schiff-base complex as an efficient nanocatalyst for the synthesis of newly reported derivatives of pyrano[2,3-b] pyridine-3-carboxamide from one-pot multicomponent reactions.