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 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

An Efficient and Green Microwave-Assisted Synthesis of Quinoline DerivativesviaKnoevengal Condensation

2020 ◽  
Vol 17 (2) ◽  
pp. 157-163 ◽  
Author(s):  
Syed Tasqeeruddin ◽  
Yahya Asiri ◽  
Jaber Abdullah Alsherhri
Keyword(s):  
Green Synthesis ◽  
Knoevenagel Condensation ◽  
Microwave Assisted Synthesis ◽  
Quinoline Derivatives ◽  
Efficient Catalyst ◽  
Microwave Assisted ◽  
Active Methylene Compounds ◽  
Active Methylene ◽  
Quinolone Derivatives

:We have developed an efficient and green synthesis of quinoline derivatives using L-proline under Knoevenagel condensation. L-proline was found to be an efficient catalyst for the Knoevenagel condensation of substituted 2-aminoaryl ketones 1 with the active methylene compounds 2, affording quinolone derivatives 3. The reaction has been done under conventional as well as under microwave conditions. The latter procedure has been found to be much more efficient in terms of time and yield.

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.

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.

Urotropine: An Efficient Catalyst Precursor for the Microwave-Assisted Knoevenagel Reaction

2001 ◽  
Vol 2001 (5) ◽  
pp. 188-189 ◽  
Author(s):  
Yanqing Peng ◽  
Gonghua Song ◽  
Xuhong Qian
Keyword(s):  
Knoevenagel Reaction ◽  
Catalyst Precursor ◽  
Efficient Catalyst ◽  
Microwave Assisted ◽  
Active Methylene Compounds ◽  
Active Methylene

By using urotropine as a catalyst precursor, a rapid microwave-assisted Knoevenagel reaction of various active methylene compounds with aldehydes gave the corresponding olefinic products with satisfactory yields.

scholarly journals Zirconium(IV) Oxychloride: A Simple and Efficient Catalyst for the Synthesis of Chromen-2-one Derivatives

2020 ◽  
Vol 32 (10) ◽  
pp. 2611-2616
Author(s):  
S. Tasqeeruddin ◽  
Yahya I. Asiri ◽  
S. Shaheen
Keyword(s):  
Reaction Time ◽  
Spectral Data ◽  
Rapid Method ◽  
Knoevenagel Condensation ◽  
Efficient Catalyst ◽  
Operational Procedure ◽  
Green Protocol ◽  
Environmental Friendly ◽  
Active Methylene Compounds ◽  
Active Methylene

The present work explores a highly efficient, environmental friendly, green protocol for the synthesis of chromen-2-one derivatives (3a-m) by the condensation of salicylaldehydes with various active methylene compounds using zirconium (IV) oxychloride as catalyst. This is a convenient and rapid method for Knoevenagel condensation and this methodology offers several advantages including shorter reaction time, milder conditions, inexpensive catalyst, simple operational procedure and allowed to achieve the desired products in excellent yields. The structures of all the synthesized compounds were confirmed by spectral data.

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.

The remarkable catalytic activity of ultra-small free-CeO2 nanoparticles in selective carbon–carbon bond formation reactions in water at room temperature

2015 ◽  
Vol 39 (7) ◽  
pp. 5350-5353 ◽  
Author(s):  
Subhash Banerjee
Keyword(s):  
Catalytic Activity ◽  
Room Temperature ◽  
Bond Formation ◽  
Ceo2 Nanoparticles ◽  
Cerium Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Reusable Catalyst ◽  
Carbon Carbon Bond ◽  
Active Methylene Compounds ◽  
Active Methylene

A simple and efficient protocol for selective bis-Michael addition and mono-allylation of active methylene compounds has been demonstrated using ultra-small size (∼5 nm) uncapped cerium oxide nanoparticles (free-CeO2 NPs) as a reusable catalyst in water at room temperature.

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