Regulation of polar microenvironment on the surface of tertiary amines functionalized polyacrylonitrile fiber and its effect on catalytic activity in Knoevenagel condensation

2019 ◽  
Vol 118 ◽  
pp. 19-24 ◽  
Author(s):  
Lishuo Zheng ◽  
Pengyu Li ◽  
Minli Tao ◽  
Wenqin Zhang
Keyword(s):  
Catalytic Activity ◽  
Knoevenagel Condensation ◽  
Polyacrylonitrile Fiber ◽  
Tertiary Amines

Investigation of the basis of catalytic activity of solid state phosphate complexes in the Knoevenagel condensation

2003 ◽  
Vol 202 (1-2) ◽  
pp. 247-252 ◽  
Author(s):  
Jamal Bennazha ◽  
Mohamed Zahouilly ◽  
Ali Boukhari ◽  
Elizabeth M Holt
Keyword(s):  
Catalytic Activity ◽  
Solid State ◽  
Knoevenagel Condensation

scholarly journals Cu(II) and magnetite nanoparticles decorated melamine-functionalized chitosan: A synergistic multifunctional catalyst for sustainable cascade oxidation of benzyl alcohols/Knoevenagel condensation

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Zahra Alirezvani ◽  
Mohammad G. Dekamin ◽  
Ehsan Valiey
Keyword(s):  
Catalytic Activity ◽  
Knoevenagel Condensation ◽  
Ambient Pressure ◽  
Reaction Medium ◽  
Environmentally Benign ◽  
One Pot ◽  
Benzyl Alcohols ◽  
External Magnet ◽  
Multistep Synthesis ◽  
Multifunctional Catalyst

AbstractThe uniform decoration of Cu(II) species and magnetic nanoparticles on the melamine-functionalized chitosan afforded a new supramolecular biopolymeric nanocomposite (Cs-Pr-Me-Cu(II)-Fe3O4). The morphology, structure, and catalytic activity of the Cs-Pr-Me-Cu(II)-Fe3O4 nanocomposite have been systematically investigated. It was found that Cs-Pr-Me-Cu(II)-Fe3O4 nanocomposite can smoothly promote environmentally benign oxidation of different benzyl alcohol derivatives by tert-butyl hydroperoxide (TBHP) to their corresponding benzaldehydes and subsequent Knoevenagel condensation with malononitrile, as a multifunctional catalyst. Interestingly, Fe3O4 nanoparticles enhance the catalytic activity of Cu(II) species. The corresponding benzylidenemalononitriles were formed in high to excellent yields at ambient pressure and temperature. The heterogeneous Cs-Pr-Me-Cu(II)-Fe3O4 catalyst was also very stable with almost no leaching of the Cu(II) species into the reaction medium and could be easily recovered by an external magnet. The recycled Cs-Pr-Me-Cu(II)-Fe3O4 was reused at least four times with slight loss of its activity. This is a successful example of the combination of chemo- and bio-drived materials catalysis for mimicing biocatalysis as well as sustainable and one pot multistep synthesis.

scholarly journals Hydrogenation of unactivated enamines to tertiary amines: rhodium complexes of fluorinated phosphines give marked improvements in catalytic activity

2015 ◽  
Vol 11 ◽  
pp. 622-627 ◽  
Author(s):  
Sergey Tin ◽  
Tamara Fanjul ◽  
Matthew L Clarke
Keyword(s):  
Catalytic Activity ◽  
Environmentally Benign ◽  
Acid Extraction ◽  
Rhodium Complexes ◽  
Tertiary Amines

In the hydrogenation of sluggish unactivated enamine substrates, Rh complexes of electron-deficient phosphines are demonstrated to be far more reactive catalysts than those derived from triphenylphosphine. These operate at low catalyst loadings (down to 0.01 mol %) and are able to reduce tetrasubstituted enamines. The use of the sustainable and environmentally benign solvent (R)-limonene for the reaction is also reported with the amine isolated by acid extraction.

scholarly journals Simple Protocol for the Knoevenagel Condensation Under Solvent Free Conditions using Tungstophosphoric Acid as Catalyst

2019 ◽  
Vol 31 (10) ◽  
pp. 2181-2184
Author(s):  
Abdulrahman I. Alharthi
Keyword(s):  
Catalytic Activity ◽  
Reaction Time ◽  
Room Temperature ◽  
Model Compound ◽  
Knoevenagel Condensation ◽  
Maximum Yield ◽  
Tungstophosphoric Acid ◽  
Grinding Method ◽  
Solvent Free Conditions ◽  
Simple Protocol

The effect of calcination on the performance of tungstophosphoric acid for the product of Knoevenagel condensation was investigated. Substituted aldehydes and dimedone has been used in the presence of calcined tungstophosphoric acid as a heterogeneous catalyst using grinding method at room temperature. The results of reactions revealed that calcined tungstophosphoric acid has superior catalytic activity comparing to non-calcined catalyst in terms of yield and reaction time. Maximum yield of model compound was achieved by using 10 mol% of calcined catalyst in a reaction time that does not exceed 10 min, whereas the yield at same amount of non-calcined catalyst was 86 % in a reaction time of 35 min.

scholarly journals Syntheses of ZnO with Different Morphologies: Catalytic Activity toward Coumarin Synthesis via the Knoevenagel Condensation Reaction

2019 ◽  
Vol 58 (9) ◽  
pp. 5703-5714 ◽  
Author(s):  
Md. R. Shakil ◽  
Andrew G. Meguerdichian ◽  
Habiba Tasnim ◽  
Alireza Shirazi-Amin ◽  
Mohammad S. Seraji ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Knoevenagel Condensation ◽  
Condensation Reaction ◽  
Knoevenagel Condensation Reaction ◽  
Coumarin Synthesis

scholarly journals Layer-Like Zeolite X as Catalyst in a Knoevenagel Condensation: The Effect of Different Preparation Pathways and Cation Exchange

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 474
Author(s):  
Jan-Paul Grass ◽  
Katharina Klühspies ◽  
Bastian Reiprich ◽  
Wilhelm Schwieger ◽  
Alexandra Inayat
Keyword(s):  
Catalytic Activity ◽  
Reaction Rate ◽  
Knoevenagel Condensation ◽  
Ethyl Cyanoacetate ◽  
Reaction Rates ◽  
Initial Reaction Rate ◽  
Comparative Investigation ◽  
Morphological Properties ◽  
Initial Reaction ◽  
Zeolite X

This study is dedicated to the comparative investigation of the catalytic activity of layer-like Faujasite-type (FAU) zeolite X obtained from three different synthesis routes (additive-free route, Li2CO3 route, and TPOAC route) in a liquid-phase Knoevenagel condensation of benzaldehyde and ethyl cyanoacetate to ethyl trans-α-cyanocinnamate. It is shown that the charge-balancing cations (Na+ and K+) and the morphological properties have a strong influence on the apparent reaction rate and degree of conversion. The highest initial reaction rate could be found for the layer-like zeolite X synthesised by the additive-free route in the potassium form. In most cases, the potassium-exchanged zeolites enabled higher maximum conversions and higher reaction rates compared to the zeolite X catalysts in sodium form. However, very thin crystal plates (below 100 nm thickness), similar to those obtained in the presence of TPOAC, did not withstand the multiple aqueous ion exchange procedure, with the remaining coarse crystals facilitating less enhancement of the catalytic activity.

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