The Knoevenagel condensation uses a catalytic base such as piperidine to convert an aldehyde or ketone and an activated methylene compound to a α,β-unsaturated dicarbonyl or related compound. The base deprotonates the methylene compound, creating a resonance stabilized enolate, which reacts with an iminium ion made from the carbonyl compound and the 1° or 2° amine to yield a tetrahedral intermediate. A 1,2-elimination affords the desired α,β-unsaturated dicarbonyl or related compound.

  • Reagents: Weak Catalytic Base (1°, 2°, 3° Amine, TiCl4/Et3N, KF, etc.), Dipolar Aprotic Solvent (e.g. DMF)
  • Reactant: Aliphatic/Aryl Aldehyde or Ketone, Activated Methylene Compound (Malonic Ester, Acetoacetic Ester, etc.)
  • Product: α,β-Unsaturated Dicarbonyl or Related Compound
  • Type of Reaction: Base-Catalyzed Aldol Condensation


Top Citations

Original Paper

Related Reactions

  • Acetoacetic Ester Synthesis
  • Malonic Ester Synthesis

Related Compounds

  • Aldehyde
  • Ketone
By shuhan yang


Just added to your wishlist:
My Wishlist
You've just added this product to the cart:
Go to cart page