Active‐Metal Template Synthesis of a Molecular Trefoil Knot

Tying the knot: The marriage of catalysis and coordination chemistry enables two CuI ions (red; see picture) to work in partnership for the synthesis of a molecular trefoil knot. One ion entangles an acyclic building block to create a loop in the ligand, and the other gathers the ligand's reactive end-groups, threads the loop, and catalyzes the covalent capture of the knotted architecture by an alkyne–azide “click” reaction.