Sangkaworn J.Limprasart W.Höfler M.V.Gutmann T.Pornsuwan S.Bunchuay T.Tantirungrotechai J.Mahidol University2025-04-012025-04-012025-12-01Scientific Reports Vol.15 No.1 (2025)https://repository.li.mahidol.ac.th/handle/123456789/108546This study presents an appealing approach to sustainable catalysis using cellulose filter paper as a support for copper-catalyzed reactions. The paper was functionalized with thiol groups through a reaction with thioglycolic acid, which served a dual purpose: partially reducing Cu(II) to Cu(I) and stabilizing active copper species via Cu–S interactions. Spectroscopic analysis confirmed the formation of highly dispersed multi-valent Cu2O/CuO on the thiol-functionalized cellulose, resulting in a highly efficient copper catalyst. This catalyst demonstrated excellent performance in the oxidative coupling of various amines to imines, achieving yields of 39–99% within 10–30 min. A key advantage of this system is its reusability; the catalyst maintained remarkable stability and activity over ten reaction cycles with straightforward recovery. This paper-based catalyst offers a promising strategy for eco-friendly and cost-effective synthetic processes, with significant implications for green chemistry and industrial applications.MultidisciplinaryArticleSCOPUS10.1038/s41598-025-95144-12-s2.0-10500046113820452322