The Knövenagel condensation has been an important tool for constructing the α,β-unsaturated structure unit from a carbonyl and an active methylene components. 1., and The reaction is usually carried out in the presence of a weak base, which includes aliphatic amines such as ethylenediamine and piperidine or corresponding ammonium salts, 2., and amino acids such as glycine and β-alanine, 3., and and potassium fluoride. 4 The reaction is strongly dependent on ...