▎ 摘　　要

L-arginine modified graphene oxide (GO-Arg) was introduced as a new heterogeneous biocatalyst for synthesis of benzo[b]pyran and pyrano[3,2-c]chromene derivatives. First GO was synthesized and then, Arg was covalently bonded on its surface. The new catalyst was analyzed using spectroscopic techniques such as Fourier transform infrared (FT-IR), X-ray diffraction (XRD), Field emission scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Energy-dispersive X-ray spectroscopy (EDS) and Raman. XRD analysis results showed that, Arg was located between the graphene oxide layers. Comparison of the bond intensity ratio of the D and G (ID/IG) in GO and GO-Arg confirmed the presence of Arg via covalent bond on the GO surface. XPS analysis also confirmed the successful modification through the presence of C -N bonds in the structure. Moreover, changes in morphology of the samples were observed using SEM analyze, respectively. Evaluation of the performance of the catalyst in the synthesis of benzo[b]pyran and pyrano[3,2-c]chromene derivatives showed presentable results. Using of amino acid as an available organocatalyst, its stabilization by a simple method on graphene oxide, reusing the catalyst up to 5 times, and introducing a highly pure product are positive points of this work. (c) 2022 Elsevier B.V. All rights reserved.