13858-67-8

Upstream product

• 104-55-2 3-phenyl-propenal 
• 123-54-6 acetylacetone 
• 41002-50-0 4-acetoxy-3-penten-2-one 
• 14371-10-9 (E)-3-phenylpropenal 
• 4187-87-5 1-Phenyl-2-propyn-1-ol 

Downstream Products

• 1216-15-5 cinnamaldehyde phenylhydrazone 
• 1257319-43-9 C₂₆H₂₄N₂O₂ 
• 1257319-44-0 C₂₈H₂₈N₂O₂ 
• 1257319-41-7 C₂₆H₂₂N₄O₄ 
• 1257319-42-8 C₂₆H₂₄N₂ 
• 87497-32-3 1,7-Bis-dimethylamino-4-((E)-3-phenyl-allylidene)-heptane-3,5-dione; hydrochloride 
• 87497-31-2 6-Dimethylamino-3-[(E)-3-phenyl-prop-2-en-(Z)-ylidene]-hexane-2,4-dione; hydrobromide 
• 1399383-36-8 ethyl 6-acetyl-2,3-dihydro-7-methyl-3-phenyloxepine-2-carboxylate 
• 1399383-27-7 ethyl 4-acetyl-2,3-dihydro-5-methyl-3-[(E)-2-phenylethenyl]furan-2-carboxylate 
• 1399383-16-4 dimethyl 6-acetyl-7-methyl-3-phenyloxepine-2,2(3H)-dicarboxylate 
• 1399383-04-0 dimethyl 4-acetyl-5-methyl-3-[(E)-2-phenylethenyl]furan-2,2(3H)-dicarboxylate 

Relevant academic research and scientific papers

Biological screening and DNA nuclease activity of transition metal complexes of N2O2 type of Knoevenagel condensate Schiff base

A novel tetradentate N2O2 type of Knoevenagel condensate Schiff base, synthesized from 4-amino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one (4-aminoantipyrine) and 3-(cinnamyl)-pentane-2,4-dione, forms stable complexes with transition met

Domino Self-Sensitized Photooxygenation of Conjugated Dienones for the Synthesis of 1,2,4-Trioxanes

The photochemical behavior of several dienones was studied under aerobic conditions. 2-Allylidene-1,3-cycloalkanediones prepared via Knoevenagel-type condensation between simple readily available 1,3-dicarbonyl substrates and α,β-unsaturated aldehydes aff

Corrigendum to: Enzyme Promiscuity as a Remedy for the Common Problems with Knoevenagel Condensation (Chemistry – A European Journal, (2019), 25, 43, (10156-10164), 10.1002/chem.201901491)

In the published paper, there is a mistake in the labelling of compounds in Figure. A corrected version of that Figure appears below. The authors apologise for the mistake. Figure (Figure presented.) Unsaturated 2,4-pentanediones obtained by enzyme-catalyzed tandem Knoevenagel reaction. Reaction conditions: aldehyde (1 mmol), 4-acetoxy-3-penten-2-one (5 a, R1=R2=R3=Me) (3 mmol), and PPL (100 mg) in tert-butyl alcohol/ 5 % H2O v/v (2 mL) for 72 h at 20 °C, 200 rpm. [a] With vinyl acetate. [b] With ethyl β-styrylcarbonate. [c] With styryl acetate.

Cross-linked polystyrene-TiCl4 complex as a reusable Lewis acid catalyst for solvent-free Knoevenagel condensations of 1,3-dicarbonyl compounds with aldehydes

Cross-linked polystyrene copolymer beads with the average particle size in the range of (50–80 mesh size) were prepared by a new method, characterized and functionalized with titanium tetrachloride to afford the corresponding polystyrene?titanium tetrachloride complex in one step reaction and characterized by FT-IR, UV, TGA, DSC, XRD, SEM, BET. This polymer metal complex (PS/TiCl4) was used as a heterogeneous, recoverable, reusable Lewis acid for solvent-free Knoevenagel condensations of 1,3-diketones with aromatic aldehydes under green and mild conditions. The rate of reactions was found to decrease with an increasing percentage of crosslinking and the mesh size of the copolymer beads. This complex showed good stability and catalytic activity in the Knoevenagel reactions.

Enzyme Promiscuity as a Remedy for the Common Problems with Knoevenagel Condensation

A new protocol based on lipase-catalyzed tandem reaction toward α,β-enones/enoesters is presented. For the synthesis of the desired products the tandem process based on enzyme-catalyzed hydrolysis and Knoevenagel reaction starting from enol acetates and aldehyde is developed. The relevant impact of the reaction conditions including organic solvent, enzyme type, and temperature on the course of the reaction was revealed. It was shown that controllable release of the active methylene compound from the corresponding enol carboxylate ensured by enzymatic reaction diminishes significantly the formation of the unwanted co-products. Furthermore, this protocol was extended by including a second tandem chemoenzymatic transformation engaging various aldehyde precursors. After a careful optimization of the reaction conditions, the target products were obtained with yields up to 86 % and with excellent E/Z-selectivity.

Base-Promoted Tandem Cyclization for the Synthesis of Benzonitriles by C?C Bond Construction

A facile synthesis of benzonitriles via a base-promoted tandem cyclization reaction of α,β-unsaturated enones having electron-withdrawing group (EWG) and 2-acyl-acrylonitriles was developed. This new synthetic method to access benzonitriles is suitable for a wide range of substrates. A plausible reaction mechanism is proposed on the basis of previous literature and our own investigations. (Figure presented.).

Lipase-catalyzed Knoevenagel condensation between α,β- unsaturated aldehydes and active methylene compounds

A simple and efficient Knoevenagel condensation between α,β-unsaturated aldehydes and active methylene compounds is reported. Notably, this condensation can be catalyzed by PPL (lipase from porcine pancreas) with satisfied yields (49%-92%). Moreover, PPL induces moderate Z/E selectivity in the Knoevenagel condensation.

Biocatalytic Knoevenagel reaction using alkaline protease from Bacillus licheniformis

BLAP (alkaline protease from Bacillus licheniformis) was used as a biocatalyst in the Knoevenagel condensations of aromatic, hetero-aromatic and α;β-unsaturated aldehydes with less reactive acetylacetone or ethyl acetoacetate. The reactions were performed in organic solvent in the presence of water. The functionalized trisubstituted alkenes and α,β,γ, δ-unsaturated carbonyl compounds could be obtained in moderate to good yields with E/Z selectivities up to >99:1. This biocatalytic reaction provided an alternative pathway for Knoevenagel condensation, which also demonstrates a novel case of unnatural activity of existing enzymes.

Enzyme catalytic promiscuity: The papain-catalyzed Knoevenagel reaction

Papain as a sustainable and inexpensive biocatalyst was used for the first time to catalyze the Knoevenagel reactions in DMSO/water. A wide range of aromatic, hetero-aromatic and α,β-unsaturated aldehydes could react with less active methylene compounds acetylacetone and ethyl acetoacetate. The products were obtained in moderate to excellent yields with Z/E selectivities of up to 100:0. This case of biocatalytic promiscuity not only widens the application of papain to new chemical transformations, but also could be developed into a potentially valuable method for organic synthesis.

Efficient solvent-free knoevenagel condensation between -diketone and aldehyde catalyzed by silica sulfuric acid

Silica sulfuric acid has been utilized as an efficient heterogeneous recyclable catalyst for Knoevenagel condensation between poorly reactive β-diketones and aldehydes under solvent-free conditions. This protocol also works well with more reactive β-ketoesters. The condensation is efficient, clean, and mild. The scope and generality of the Knoevenagel condensation were investigated. The procedure led only to the Knoevenagel product, and no side product derived from a subsequent Michael βaddition of -diketone to alkene was detected at rt. Increasing temperature led to a subsequent Michael addition, and it was applied to the efficient synthesis of 9-aryl-1,8-dioxo- octahydroxanthene derivatives.