Mechanistic insights into the CO₂-based synthesis of cyclic carbonates in micellar systems

The fixation of carbon dioxide (CO₂) from waste streams into value-added products through organic synthesis presents significant ecological benefits despite its challenges. Although a reaction involving the formal cycloaddition of CO₂ to epoxides, resulting in cyclic carbonates, can be carried out under aqueous conditions, a thorough understanding of the underlying mechanisms in micellar catalysis is essential for optimizing such transformations. In this study, we employ advanced density functional theory (DFT) and Conductor-like Screening Model for Real Solvents (COSMO-RS) calculations, alongside detailed NMR investigations, to elucidate the co-localization of reactants under micellar conditions. Our mechanistic insights reveal that CO₂ is strategically distributed within the micelle core and in water, where it is bound to an amine shuttle that efficiently transports it from the gaseous phase. Furthermore, the developed micellar system also allows for efficient carbon disulfide (CS₂) cycloaddition to epoxides and aziridines.