Caffeine gold complex supported on magnetic nanoparticles as a green and high turnover frequency catalyst for room temperature A3 coupling reaction in water

A new heterogeneous catalyst derived from gold (III) and supported on caffeine‐coated magnetic nanoparticles, Fe₃O₄@Caff‐Au, has been prepared and characterized using different techniques. This magnetic gold composite shows high catalytic activity in A³ coupling reactions of terminal alkynes, aldehydes and secondary amines. Using this green catalyst, propargylamines are obtained in high turnover frequency in short reaction times using water as solvent at room temperature. This stable and ready accessible catalyst can be easily recycled magnetically for at least nine consecutive runs without significant loss of activity and with slight aggregation of Au species.