10.1055/s-0028-1087950
The research presents the synthesis of novel chiral ionic liquids (CILs) based on L-(+)-tartaric acid, leveraging its low cost and renewability as a chiral pool source. The study's main content involves a two-step synthesis strategy: first, reacting L-tartaric acid with benzylamine to form pyrrolidindione, followed by reduction with LiAlH4 to obtain benzylpyrrolidine. Subsequent quaternization with benzyl or n-dodecyl bromide under conventional or microwave heating yielded the desired chiral pyrrolidinium salts. The synthesized compounds were characterized by their melting points, and anion exchange was performed to obtain different ionic liquids. The researchers also examined the crystallographic structures of selected compounds to understand the absence of hydrogen-bonding interactions between cations, which contributed to the reduced melting points. The chiral recognition ability of these ionic materials was evaluated through NMR spectroscopy, observing the interaction between the synthesized cations and Mosher acid anion, which indicated the formation of diastereomeric salts. This research provides a foundation for further investigation into the potential of these CILs as solvents, catalysts, or ligands in asymmetric synthesis.