A review of the latest advances in click reaction using magnetite nanocatalysts

Magnetic nanocatalysts, in particular magnetite (Fe₃O₄)-based, have been leading the way in the last decade for serving as the key to facilitating efficient, green, and sustainable organic reactions. One of their most significant applications is in the area of click chemistry, more particularly copper-catalyzed azide-alkyne cycloaddition (CuAAC) reactions, which find universal application in the synthesis of 1,2,3-triazoles important pharmacophores in pharmaceuticals, agrochemicals, and functional materials. This review thoroughly discusses the advancements from 2018 until 2025 in the design, synthesis, and application of Fe₃O₄-based magnetic nanocatalysts in click reactions. The catalysts offer many advantages, such as high catalytic performance, superb regioselectivity, mild reaction conditions, green solvents (primarily water or water mixture), and decent reusability due to their inherent magnetic properties. Different structural strategies have been tried to improve their performance, including surface functionalization with organic ligands, metal ion doping (with copper as a particular example), and hybrid material design. Reaction mechanisms, catalysis efficiency, etc., are also discussed in the review. More recent trends such as bio-based supports, metal-organic frameworks, and sonochemical activation are also discussed, which put magnetite nanocatalysts at the forefront of future sustainable click chemistry. Additionally, structural and morphological characterizations of selected magnetic nanocatalysts have been incorporated to provide deeper insight into their properties and catalytic performances.