Economic and environmentally friendly bio-mimetic one-pot three and four-component Knoevenagel-hydrogenation (K-H), five-component Knoevenagel-hydrogenation-alkylation (K-H-A) and six-component Knoevenagel-hydrogenation-alkylation-Huisgen cycloaddition (K-H-A-HC) reactions of aldehydes, CH-acids, o-phenylenediamine, alkyl halides and azides using proline, proline-metal carbonate and proline-met...

ABSTRACT Knoevenagel condensation of barbituric acids with aromatic aldehydes containing one or two formyl groups was carried out. 5-Arylidenebarbituric acids underwent smooth hetero-Diels-Alder (HDA) reactions with enol ethers to afford cis and trans diastereoisomers of pyrano[2,3-d]pyrimidine-2,4-diones and 5,5'-(1,4-phenylene)bis[2H-pyrano[2,3-d]pyrimidine-2,4(3H)-dione] derivatives in excel...

A series of N-substituted-2,4-thiazolidinedione derivatives (TZDs) were prepared via N-alkylation of 2,4-TZD at position 3 using substituted benzyl halides. Synthesized N-substituted-2,4-TZD was then substituted at position 5 with substituted aromatic aldehyde according to Knoevenagel condensation method. Structures of the compounds were elucidated using various spectral techniques viz. IR, 1HN...

The synthesis of new α,β-unsaturated furanuronic acid derivatives of α-gluco-, β-gluco- and β-manno-chloraloses via a convenient one pot procedure using the Knoevenagel-Doebner reaction approach are described. The dialdofuranose derivatives were reacted with malonic acid under Knoevenagel-Doebner reaction conditions and (E)-α,β-unsaturated furanuronic acid derivatives were obtained.

Knoevenagel condensations between aldehydes and substrates containing active methylene groups were carried out in ethanol at room temperature, in the presence of potassium phosphate, to afford unsymmetrical olefins. These condensations have been shown to afford only the E-isomers in greater than 80% yields. Salicylaldehyde first produces the Knoevenagel condensation products, which undergo a su...

Visible light induced a highly efficient and environmentally-friendly Knoevenagel condensation of various aliphatic and aromatic aldehydes with malononitrile has been achieved in excellent yield in presence of aqueous tamarind juice. The tamarind juice could be simply prepared from unripe fruit of Tamarindus indica in water and the reactions go to completion within 2-7 min. A plausible mechanis...

A novel one-pot aerobic oxidation/Knoevenagel condensation reaction system was developed employing a Cu(ii)/amine bifunctional, basic metal-organic framework (MOF) as the catalyst. The sequential aerobic alcohol oxidation/Knoevenagel condensation reaction was efficiently promoted by the Cu3TATAT MOF catalyst in the absence of basic additives. The benzylidenemalononitrile product was produced in...

The mechanism of the TiCl4-promoted condensation of methyl acetoacetate, isobutyraldehyde, and indole was studied by a combination of theoretical and experimental techniques. The energy profile of plausible reaction paths was evaluated by DFT calculations, and various reaction intermediates were isolated or observed in solution by NMR spectroscopy. Theoretical and experimental results indicate ...

Starting from aromatic ortho-dialdehydes, we devised a homo-elongation protocol that combines a Wittig olefination and subsequent intramolecular Knoevenagel condensation to produce acene diesters and dinitriles.

A porous molecular crystalline solid based on amide-containing Pd(II) triangles was created for size-selective heterogeneous catalysis of the Knoevenagel condensation reaction.