Squaramide-functionalized coordination capsule as hydrogen-bond-donor catalyst for efficient Friedel-Crafts alkylation.

A squaramide-functionalized tetranuclear coordination capsule was constructed as an efficient catalyst for Friedel-Crafts alkylation. The supramolecular architecture suppresses self-association and creates a confined cavity enriched with directional hydrogen-bonding sites. This defined microenvironment enables substrate encapsulation, promotes activation, and stabilizes a preorganized conformation, thereby accelerating the nucleophilic addition step.