KA2‐Coupling Reaction Catalyzed by Semi‐Heterogeneous Magnetically Graphene Oxide Supported Copper Catalyst under Microwave Condition

Abstract

AbstractFunctional Schiff base chelating groups (PCA) were covalently grafted onto the surface of magnetic graphene oxide (GO‐Fe3O4) via a facile silanization reaction under mild condition. The obtained GO‐Fe3O4‐PCA was further chelated with CuCl2 as an efficient, robust, and recyclable semi‐heterogeneous catalyst (GO‐Fe3O4‐CuCl2) for one‐pot three‐component KA2 coupling of ketones, amines, and alkynes. It exhibited environmentally benign, excellent magnetic separation performance, and higher catalytic activity than other commercially available copper sources. A series of propargylamines are prepared from cycloketones, cycloamines, and phenylacetylene in moderate to excellent yields under microwave (MW) irradiation (70–93%). Interestingly, the catalyst can be separated conveniently by a simple magnetic separation and reused at least four consecutive runs with a slight drop in the product yields. The semi‐heterogeneous property and excellent accessibility of GO‐Fe3O4‐CuCl2 might cause high catalytic activity.