Résumé
Benzoin condensation consists in reacting two aldehyde functions through a resonance-stabilized enaminol-type intermediate called the Breslow intermediate. This communication describes for the first time the use of N-heterocyclic carbenes (NHCs) as organic catalysts for the step-growth polymerization of a bis-aldehyde monomer, namely terephtaldehyde, which leads to poly(l,4-phenylene-l-oxo-2-hydroxyethylene) referred to as polybenzoin. These NHC-catalyzed polymerizations presumably involve the formation of Breslow intermediates. The effect of the NHCs catalyst activity and of the solvent polarity on the kinetics of the polymerization and on the formation of linear and cyclic polybenzoins is discussed.