Harboring organocatalysts in a star-shaped block copolymer for micellar catalysis and emulsion catalysis†
Abstract
Performing organocatalysis in an aqueous environment holds great promise to mimic enzyme catalysis for its simpler preparation and modification, but also confronts considerable challenges due to the adverse effects and solubility issues caused by excess water. To meet this challenge, we report here an elegant strategy by incorporating adamantane-modified proline (Ad-pro) into a star-shaped polymer with an inherently self-folded hydrophobic center. The catalyst–polymer complex not only self-assembles into micelles in water for an asymmetric aldol reaction with high reactivity and selectivity but also stabilizes an emulsion in the biphasic system for promoting the substrates' solubility and achieving good conversion (up to 97.5%) and excellent stereoselectivity (up to 99.7%) simultaneously. This work demonstrates the application of multi-dimensional self-assembly systems for asymmetric organocatalysis, showcasing its huge potential in mimicking and coupling enzyme catalysis for advanced synthetic purposes in precision chemistry.