Synthesis and\nCharacterization of a Hercynite-Supported\nCopper(II) Complex Based on 1,10-Phenanthroline-5,6-dione and Acetylacetone\nBuilding Blocks and Its Catalytic Application in Annulation Reactions

In the present work, a novel Cu(II) complex containing\n10-phenanthroline-5,6-dione\n(phen-dione) and acetylacetone (acac) was prepared via solid-phase\nsynthesis on silica-modified hercynite magnetic nanoparticles (MNPs).\nThe resulting structure underwent thorough structural analysis using\ndiverse instrumental techniques. The catalytic potential of the synthesized\nCu(II) complex was successfully demonstrated in the synthesis of 2-amino-3-cyano-4<i>H</i>-chromenes. This was accomplished via a one-pot, three-component\ncondensation reaction involving lawsone, malononitrile, and aromatic\naldehydes in ethanol under reflux conditions, leading to remarkably\nhigh yields and product purity. Several advantages stem from this\ninvestigation. Notably, the use of ethanol as a sustainable and environmentally\nfriendly solvent highlights the ecoconscious approach of this research.\nMoreover, the reaction conditions were mild and the separation process\nwas straightforward, resulting in reduced byproducts as well as time\nand cost savings. Furthermore, the catalyst’s stability and\nreusability were studied under optimal conditions, revealing excellent\nreversibility for up to five cycles without any significant loss of\nactivity. This excellent performance underscores the potential of\nthe Cu(II) complex for sustainable catalytic applications.