Green asymmetric synthesis of binol via oxidative cross-coupling in the presence of L-cysteine@Fe3O4 nanoparticles

A green synthesis method was used to prepare racemic binol for the first time, yielding up to 92% in the presence of Fe3O4 magnetic nanoparticles in water.Additionally, an enantioselective cross-coupling of 2naphthols was conducted using a chiral magnetic nano catalyst L-cysteine@Fe3O4, leading to the preparation of the S-binol enantiomer with up to 85% yield and 80% enantioselectivity.The structure and morphology of the magnetic nanoparticles were characterized using various techniques, including energy-dispersive X-ray spectroscopy (EDAX), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), vibrating-sample magnetometer (VSM) analysis, and Fourier-transform infrared (FT-IR) spectroscopy.