Beyond Covalent Bonding: The Rise of Chiral Cations in Asymmetric Catalysis

Abstract:

Chiral cationic catalysts direct reactivity and stereocontrol through synergistic ion-pairing interactions and chiral environment enforcement, enabling asymmetric transformations. This minireview highlights the recent advances in quaternary ammonium/phosphonium, chalcogenonium salts, bisguanidinium catalysts, and metal-cooperative systems, presenting their potential in C–X bond formation and cyclization. Over the past five years, rational catalyst design, guided by computational modeling, has also gained increasing prominence. This strategy facilitated the rapid discovery of novel cationic scaffolds and provided mechanistic insights, thereby enabling precise stereocontrol and broadening the accessible substrate scope. The future perspective of chiral cation catalysts centres on developing robust, tunable frameworks, integrating multi-catalytic systems, leveraging machine learning for optimization, and enabling sustainable and highly selective asymmetric transformations.