TY - JOUR A1 - Lai, Bingbing A1 - Ye, Meng A1 - Liu, Ping A1 - Li, Minghao A1 - Bai, Rongxian A1 - Gu, Yanlong T1 - A novel and robust heterogeneous Cu catalyst using modified lignosulfonate as support for the synthesis of nitrogen-containing heterocycles JF - Beilstein Journal of Organic Chemistry PY - 2020/// VL - 16 SP - 2888 EP - 2902 SN - 1860-5397 DO - 10.3762/bjoc.16.238 PB - Beilstein-Institut JA - Beilstein J. Org. Chem. UR - https://doi.org/10.3762/bjoc.16.238 KW - biomass KW - heterogeneous catalyst KW - immobilized copper catalyst KW - lignosulfonate KW - nitrogen-containing heterocycles KW - solid acid N2 - A waste biomass, sodium lignosulfonate, was treated with sodium 2-formylbenzenesulfonate, and the phenylaldehyde condensation product was then used as a robust supporting material to immobilize a copper species. The so-obtained catalyst was characterized by many physicochemical methods including FTIR, EA, FSEM, FTEM, XPS, and TG. This catalyst exhibited excellent catalytic activity in the synthesis of nitrogen-containing heterocycles such as tricyclic indoles bearing 3,4-fused seven-membered rings, 2‑arylpyridines, aminonaphthalenes and 3-phenylisoquinolines. In addition, this catalyst showed to be recyclable and could be reused several times without significant loss in activity during the course of the reaction process. ER -