GO@dopamine-Cu as a Green Nanocatalyst for the Efficient Synthesis of Fully Substituted Dihydrofuran-2(5H)-ones

A new nanocatalyst graphene oxide@dopamine-Cu was synthesized, and its structure was characterized by fourier transform infrared (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Energy Dispersive X-ray Spectrometry (EDX), and thermogravimetric analysis – differential thermal analysis (TGA-DTA) techniques. The three-component one-pot reaction between an arylamine, aromatic aldehyde, and acetylenic carboxylate was achieved and formed methyl 5-oxo-2-aryl-4-(arylamino)-2,5-dihydrofuran-3-carboxylate derivatives (4) in the presence of the catalytic amount of graphene oxide@dopamine-Cu nanocatalyst in high yield. Molecular structures of products were characterized by FT-IR, 1H, 13C nuclear magnetic resonance (NMR), and Mass spectroscopy techniques. Representatively, the mass fragmentation of 4a was discussed, and the structure was confirmed. Easy reaction, high performance, and easy catalyst recyclability are the main advantages of this work. This nanocatalyst is recycled up to five successive runs.