Immobilized Cu(II) Schiff base complex supported on Fe₃O₄ magnetic nanoparticles: A highly efficient and reusable new catalyst for the synthesis of pyranopyridine derivatives

Abstract

A new copper(II) Schiff base complex immobilized on silica‐coated nanomagnetic Fe 3 O 4 was synthesized from acetylacetonate (acac) and 2‐aminothiophenol (ATP). The newly synthesized nanocatalyst, Fe 3 O 4 @SiO 2 ‐acac‐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(1 H )‐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.