Design and Synthesis of a Cluster-Based Supramolecular Reaction Pump for the Efficient Catalysis of Amination Reactions

Although discrete self-assembled cage compounds with single-metal centers mimicking natural bioreactors for catalysis have been extensively investigated, studies on those with multimetal active centers, i.e., cluster active centers (CACs), have been less explored. Herein, we present the design and synthesis of a novel cluster-based supramolecular reaction pump (CSRP-1) featuring four CACs that facilitate catalysis. CSRP-1 holds a cationic supramolecular tetrahedral structure, comprising four WS₃Cu₃ clusters, each positioned at one vertex and interconnected by dipyridyl linkers. Substrates, including aryl iodides or primary or secondary amines, enter the cage cavity by replacing N,N-dimethylformamide at the CACs through weak Cu···I/N interactions. This design leverages the coordinatively unsaturated Cu centers within each CAC to activate the substrates, resulting in efficient catalytic amination. CSRP-1 works like a dynamic pump, and upon completion of the reaction, the amine product is expelled from the cavity, allowing the catalytic cycle to repeat with maintained efficiency. Theoretical calculations complement the experimental findings, providing key insights into the catalytic mechanism and the synergistic role of the clusters and linkers. This work offers a new catalysis paradigm with broad applicability to various organic reactions.