27669-22-3

Upstream product

• 123-54-6 acetylacetone 
• 552-89-6 2-nitro-benzaldehyde 
• 41002-50-0 4-acetoxy-3-penten-2-one 

Downstream Products

• 33331-55-4 ethyl 5-acetyl-2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3-carboxylate 
• 60467-24-5 4-[methoxy-(2-nitro-phenyl)-methyl]-3,5-dimethyl-isoxazole 
• 60467-25-6 (XV) 
• 27669-24-5 3-Acetyl-2-methyl-chinolin-N-oxid 
• 34551-63-8 (2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-diyl)diethanone 
• 94771-65-0 (E)-2-Acetyl-3-(2-nitrobenzylidenamino)-indol 
• 14208-35-6 1-(2-methylquinolin-3-yl)ethanone 
• 860364-95-0 5-acetyl-4-(2-amino-phenyl)-2,6-dimethyl-nicotinic acid ethyl ester 
• 94398-03-5 3,5-Diacetyl-2,6-dimethyl-4-(2-nitrophenyl)-pyridin 

Relevant academic research and scientific papers

Synthesis of Functionalized Quinolines from 4-(o-Nitroaryl)-Substituted 3-Acyl-4,5-Dihydrofurans: Reductive Cyclization and C=C Bond Cleavage

A new synthetic approach to functionalized quinolines was developed based on the application of Zn–AcOH system as a simple and efficient reductive agent towards 4-(o-nitroaryl)-3-acyl-substituted 4,5-dihydrofurans. Reduction of 3-carbonyl-substituted dihy

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.

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.

Efficient promiscuous Knoevenagel condensation catalyzed by papain confined in Cu3(PO4)2 nanoflowers

To develop an efficient and green immobilized biocatalyst for promiscuous catalysis which has a broad scope of applications, hybrid nanoflower (hNF) confined papain as a biocatalyst has been proposed and characterized in this study. hNFs were firstly prepared through mixing CuSO4 aqueous solution with papain in phosphate saline (PBS) at room temperature. The resulting hNFs were characterized by SEM and verified through a hydrolysis reaction with N-benzoyl-dl-arginine amide as substrate. Under optimal conditions, this nano-biocatalyst demonstrated a 15-fold hydrolytic activity compared with papain of free form, along with better thermal stability. A series of reaction factors (reaction temperature, time, and solvent) have been investigated for Knoevenagel condensation reactions with hNFs as catalyst. At optimal conditions, product yield of the hNFs catalyzed reaction was 1.3 fold higher than that of the free enzyme with benzaldehyde and acetylacetone as substrates. A few aldehydes and methylene compounds have also been used to test the generality and scope of this new enzymatic promiscuity. To sum up, the obtained hNFs demonstrate better catalytic properties than free papain and the inorganic metal-salt crystal can function as both support and promotor in biocatalysis.

Knoevenagel condensation of aromatic aldehydes with active methylene compounds catalyzed by lipoprotein lipase

A screening of using different lipases to catalyze the Knoevenagel reaction was realized, and lipase lipoprotein (LPL) from Aspergillus niger showed the best catalytic performance. The reaction conditions including solvent, enzyme loading, and temperature were screened to improve the reaction efficiency. Various kinds of substrates were investigated, and almost all the target products were obtained in good to excellent yields (76-98%) with Z configuration exclusively. This procedure provides a novel, green and efficient method for the Knoevenagel condensation of aromatic aldehydes with active methylene compounds.

A facile synthesis of trisubstituted alkenes from β-diketones and aldehydes with AlCl3 as catalyst

Preparation of trisubstituted alkenes from low-activity β-diketones and aldehydes with aluminum chloride as catalyst has been studied. The frequently used catalyst AlCl3 is used for the first time to promote this condensation. The procedure is a convenient, low toxicity, and highly efficient method for industrial synthesis of trisubstituted alkenes in high yield. Springer Science+Business Media B.V. 2011.

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.

Catalyst-free multicomponent synthesis of β-mercapto diketones in water

A simple, efficient and eco-friendly route has been developed for the synthesis of β-mercapto diketones via a multicomponent reaction of an aldehyde, acetylacetone and thiol in water. This methodology affords a number of β-mercapto diketone derivatives in

Selective reduction of nitroarenes by a Hantzsch 1,4-dihydropyridine: A facile and efficient approach to substituted quinolines

An efficient reductive cyclization of o-nitrocinnamoyl compounds was achieved by employing a Hantzsch 1,4-dihydropyridine ester as a biomimetic reducing agent in the presence of catalytic palladium on carbon. This approach was successfully applied to the synthesis of substituted quinolines. Georg Thieme Verlag Stuttgart ? New York.