Design of a Chiral Ionic Liquid System for the Enantioselective Addition of Diethylzinc to Aldehydes

Abstract

An important contribution to the field of asymmetric catalysis is described in this work, as it merges the search for new ligands that can provide high performance in asymmetric catalysis with the extremely important and increasing need for sustainability. New chiral ionic liquids have been synthesised from the amino acid l‐cysteine by straightforward routes. With these ligands, we have developed a chiral ionic system that includes chiral ionic liquids and their immobilisation in ionic solvents to provide a chiral supramolecular structure. These new catalytic systems were used in the enantioselective addition of alkylzinc to aldehydes and proved to be very efficient, capable of providing chiral secondary alcohols in excellent enantiomeric excesses and yields. This system also enabled the recycling of the ionic media and the ionic ligand, taking into account green chemistry considerations.

Thiazolidine-Based Fluorescent Chiral Ionic Liquids for Trace Copper(II) Ion Sensing

“…On the other hand, imparting chirality to the cation requires more intricate synthetic routes. Recently, chiral ionic liquids derived from L-cysteine derivatives have demonstrated high efficiency as catalysts in the enantioselective addition of diethylzinc to aldehydes [21]. Other derivatives derived from L-phenylalanine and L-tyrosine have been reported, aiming to develop agents with antimicrobial activity [22], and sensors for bovine serum albumin (BSA) were prepared from L-serine [23].…”