A Magnetoclick Imidazolidinone Nanocatalyst for Asymmetric 1,3‐Dipolar Cycloadditions

A 1,3-dipolar azide-alkyne cycloaddition has been used to prepare a magnetic nanoparticle immobilized MacMillan catalyst that catalyzes the enantioselective 1,3-dipolar cycloaddition between nitrones and ,-unsaturated aldehydes. The catalyst can be recovered and recycled for five consecutive runs without any significant loss in yields and diastereo- and enantioselectivities of the isoxazolidines.