Solvent-Free Selective Condensations Based on the Formation of the Olefinic (C=C) Bond Catalyzed by Organocatalyst

Pyrrolidine and its derivatives were used to catalyze aldol and Knoevenagel condensations for the formation of the olefinic (C=C) bond under solvent-free conditions. The 3-pyrrolidinamine showed high activity and afforded excellent yields of α,β-unsaturated compounds. The aldol condensation of aromatic/heterocyclic aldehydes with ketones affords enones in high conversion (99.5%) and selectivity (92.7%). Good to excellent yields of α,β-unsaturated compounds were obtained in the Knoevenagel condensation of aldehydes with methylene-activated substrates.