Asymmetric Catalysis Promoted by Hierarchical Chirality of Metal Nanoclusters
Asymmetric catalysis is a cornerstone for producing enantiopure fine chemicals and pharmaceuticals, yet conventional nanoparticle catalysts suffer from limited enantioselectivity, high catalyst loading, and ill-defined active sites. Chiral metal nanoclusters (NCs) have emerged as a frontier due to their atomically precise structures and hierarchical chirality spanning the metal core, metal-ligand interface, ligand body, and assembly patterns. This review systematically summarizes recent progress in the synthesis and asymmetric catalytic applications of chiral metal NCs, organized by their core-shell structural scheme. The structural origins of cluster chirality are first elaborated, followed by synthetic methodologies delivering enantiopure metal NCs. Catalytic applications are then outlined, including enantioselective allylic alkylation, Suzuki-Miyaura coupling, and 1,4-addition, with enantiomeric excess (ee) values reaching up to 99% and turnover numbers (TONs) exceeding 1000 in selected systems. The review concludes with perspectives on designing chiral metal NCs for asymmetric catalysis. The fundamental and applicable advances summarized herein provide a framework for developing next-generation enantioselective catalysts with high atom economy, enhanced catalytic efficiency, and clear mechanistic pathways.