scholarly journals Efficient Knoevenagel Condensation Reactions Catalyzed by Activated Gel Zirconium(IV) Oxide

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Mohammad Reza Poor Heravi ◽  
S. Piri
Keyword(s):  
Knoevenagel Condensation ◽  
Condensation Reaction ◽  
Reaction Conditions ◽  
Condensation Reactions ◽  
Active Methylene Compounds ◽  
Active Methylene

The condensation reaction has been carried out very conveniently to obtain the corresponding substituted 2,2′-(arylmethylene)bis(3-hydroxy-5,5-dimethylcyclohex-2-enone) in excellent yields. The reaction conditions are very mild and applicable to various aldehydes as well as active methylene compounds.

Knoevenagel Reactions in Ionic Liquids

2012 ◽  
Vol 554-556 ◽  
pp. 557-561 ◽  
Author(s):  
Xiao Mei Hu ◽  
Yang Zhao ◽  
Yun Fei Gao ◽  
Yi Bo Xiao ◽  
Bi Xian Zhang
Keyword(s):  
Ionic Liquids ◽  
Large Range ◽  
Knoevenagel Condensation ◽  
Reaction Rates ◽  
Green Solvents ◽  
Efficient Procedure ◽  
Condensation Reactions ◽  
Active Methylene Compounds ◽  
High Yields ◽  
Active Methylene

Ionic liquids (ILs) as “green solvents” provided an effective and efficient procedure for Knoevenagel condensation reactions. It is applicable for a large range of aldehydes, ketones with active methylene compounds. ILs can significantly promote the reaction rates. High yields and selectivity of products have been observed. ILs can be recycled and reused. In this paper, the recent achievements of Knoevenagel condensation reactions promoted by ILs are reviewed.

Polyguanidine as a Highly Efficient and Reusable Catalyst for Knoevenagel Condensation Reactions in Water

2013 ◽  
Vol 66 (4) ◽  
pp. 500 ◽  
Author(s):  
Xian-Liang Zhao ◽  
Ke-Fang Yang ◽  
Xuan-Gan Liu ◽  
Chun-Lin Ye ◽  
Li-Wen Xu ◽  
...  
Keyword(s):  
Knoevenagel Condensation ◽  
Knoevenagel Reaction ◽  
Reusable Catalyst ◽  
Efficient Catalyst ◽  
Condensation Reactions ◽  
Highly Efficient ◽  
Wide Range ◽  
Active Methylene Compounds ◽  
Simple Filtration ◽  
Active Methylene

Polyguanidine is used as a novel and highly efficient catalyst in the Knoevenagel reaction of aldehydes with active methylene compounds in water to afford substituted electrophilic alkenes. This method is applicable for a wide range of aldehydes including aromatic and heterocyclic substrates. The polyguanidine catalyst can be recovered by simple filtration and reused many times for the aqueous Knoevenagel reaction without loss of activity.

scholarly journals Ammonium Chloride: An Efficient and Environmentally benign Catalyst for Knoevenagel Condensation of Carbonyl and Active Methylene Compounds

2020 ◽  
Vol 32 (12) ◽  
pp. 3024-3028
Author(s):  
S. Tasqeeruddin ◽  
Yahya I. Asiri ◽  
M. Mujahid A lam
Keyword(s):  
Ammonium Chloride ◽  
Large Scale ◽  
Knoevenagel Condensation ◽  
Catalytic Amount ◽  
Environmentally Benign ◽  
Reaction Conditions ◽  
Efficient Procedure ◽  
Active Methylene Compounds ◽  
Characteristic Features ◽  
Active Methylene

In the present study, a rapid, simple and an efficient procedure for the Knoevenagel condensation of various carbonyl and active methylene compounds in ethanol at a moderate temperature in the presence of a catalytic amount of an efficient, environmentally benign and inexpensive ammonium chloride is reported. Simple reaction procedure, economic and ecofriendly catalyst, mild reaction conditions and good to excellent yield of the products are the characteristic features of this study. The non-extractive workup/purification, economic and environmentally benign catalyst make this operationally straightforward procedure affordable for large scale.

Highly efficient FeNP-embedded hybrid bifunctional reduced graphene oxide for Knoevenagel condensation with active methylene compounds

2020 ◽  
Vol 44 (7) ◽  
pp. 2868-2881 ◽  
Author(s):  
Dikin Patel ◽  
Ravi Vithalani ◽  
Chetan K. Modi
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Knoevenagel Condensation ◽  
Condensation Reaction ◽  
Highly Efficient ◽  
Reduced Graphene ◽  
Active Methylene Compounds ◽  
Knoevenagel Condensation Reaction ◽  
Active Methylene

Novel hybrid bifunctional FeNPs/PPD@rGO for Knoevenagel condensation reaction with 100% conversion and yield.

scholarly journals Microwave-assisted urea catalyzed Knoevenagel condensation of aldehydes with active methylene compounds

2020 ◽  
Vol 55 (2) ◽  
pp. 159-164
Author(s):  
WT Purba ◽  
PS Roy ◽  
S Jannat ◽  
SA Begum ◽  
MM Rahman
Keyword(s):  
Microwave Irradiation ◽  
Efficient Method ◽  
Knoevenagel Condensation ◽  
Efficient Catalyst ◽  
Microwave Assisted ◽  
Solvent Free Conditions ◽  
Wide Range ◽  
Active Methylene Compounds ◽  
Reaction Proceeds ◽  
Active Methylene

Rapid and efficient method for the synthesis of substituted olefins such as 2-(4-chlorophenylmethylene) malononitrile, 2-(4-hydroxyphenylmethylene) malononitrile and 2-cyano-3-(4-hydroxyphenyl) acrylamide etc under the influence of microwave irradiation are described. Urea has been utilized as an efficient catalyst for the Knoevenagel condensation of aldehydes with acidic active methylene compounds such as malononitrile, ethylcyanoacetate and cyanoacetamide to afford substituted olefins under the influence of microwave irradiation. The reaction proceeds smoothly under mild and solvent free conditions and the products are obtained in good yield. The method is applicable for a wide range of aldehydes including aromatic and heterocyclic substrates. Bangladesh J. Sci. Ind. Res.55(2), 159-164, 2020

Cellulose Supported Tetraethylenepentamine as a Catalyst for the Knoevenagel Condensation

2003 ◽  
Vol 2003 (3) ◽  
pp. 134-135 ◽  
Author(s):  
Yi-Qun Li ◽  
Mei-Yun Zhou ◽  
Xin-Ming Xu
Keyword(s):  
Knoevenagel Condensation ◽  
Active Methylene Compounds ◽  
Active Methylene

The Knoevenagel condensation of carbonyl substrates with active methylene compounds proceeds smoothly in commercial 95% ethanol and catalysed by cellulose supported tetraethylenepentamine to afford the desired products of good purity in moderate to excellent yields.

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