A synthetic method is described to produce some chromenone-pyrazole derivatives through a one-pot multicomponent reaction using SrFe12O19 as a magnetic catalyst. This method provides quite a few merits, including the use of an effective and easy separable nanocatalyst, high yields of products, short reaction time, and easy work-up. Two of the products showed fluorescence properties, which have detected mercury ions without any interference with other ions. They can detect a tiny amount of mercury ions, which were comparable with other chemosensors. The detection limit is 4×10− 7 and 3×10− 8 M, respectively, for the compound I and II, respectively, which were considered very low amounts. The effect of mercury on health and environmental pollution is essential in medical science.

A synthetic method is described to produce some chromenone-pyrazole derivatives through a one-pot multicomponent reaction using SrFe 12 O 19 as a magnetic catalyst. This method provides quite a few merits, including the use of an effective and easy separable nanocatalyst, high yields of products, short reaction time, and easy work-up. Two of the products showed uorescence properties, which have detected mercury ions without any interference with other ions. They can detect a tiny amount of mercury ions, which were comparable with other chemosensors. The detection limit is 4×10 − 7 and 3×10 − 8 M, respectively, for the compound I and II, respectively, which were considered very low amounts. The effect of mercury on health and environmental pollution is essential in medical science.

For almost half a century of efforts to make them, the importance of Ugi products has substantially expanded because they are used as precursors for the synthesis of more complex structures, such as peptides, amino acids, pharmaceutical compounds, and heterocycles. Through the introduction of a double or triple bond along with a carbon‐halide bond in the starting materials, the Ugi adduct can be cyclized through Pd‐catalyzed intramolecular reactions to create sophisticated heterocycles. This article discusses the role of palladium in the catalytic cyclization of the Ugi adducts and covers the published research from 2000 to 2022. Moreover, the proposed mechanisms of Pd‐catalyzed annulation of Ugi adducts are also reviewed.