Let's get fluorophilic! Tagging the imidazolium ionic liquids catalytically active in redox esterification with large fluorous substituents enables their facile recovery from reaction mixtures and multiple reuse without loss of activity. It also enables their application as catalysts in fluorous biphase catalysis and supercritical CO2.
Cyclophane-type imidazolium salts with planar chirality were synthesized from enantiopure 2-amino alcohols, of which the N(1) and N(3) positions were connected with a bridge. The structural profiles of the imidazolium salts and their derivative N-heterocyclic carbenes (NHCs) were investigated by means of several analyses. The chiral NHCs derived from these imidazolium salts were found to catalyze the
Umpolung reactions in an ionic liquid catalyzed by electrogenerated N-heterocyclic carbenes. Synthesis of saturated esters from activated α,β-unsaturated aldehydes
The umpolung reaction of alpha,beta-unsaturated aldehydes to saturated esters has been carried out in an ionic liquid by organocatalysis of electrogenerated NHC. The roles of solvent, precatalyst and proton donor of the ionic liquid have been verified and good to high yields of esters have been obtained using a "green" and mild methodology.