scholarly journals Knoevenagel condensation reaction catalysed by agro-waste extract as a greener solvent catalyst

2021 ◽  
Vol 14 (1) ◽  
pp. 81-91
Author(s):  
Krishnappa B. Badiger ◽  
Kantharaju Kamanna
Keyword(s):  
Solvent Extraction ◽  
Organic Solvent ◽  
Present Method ◽  
Knoevenagel Condensation ◽  
Condensation Reaction ◽  
Knoevenagel Reaction ◽  
Organic Solvent Extraction ◽  
Knoevenagel Condensation Reaction ◽  
Waste Extract ◽  
Heterocyclic Aldehydes

This paper present a novel Knoevenagel reaction protocol for the condensation of aromatic/heteroaromatic aldehydes with malononitrile to give α, β–unsaturated benzylidene derivatives. The main focus of this work is to reveal the usability of agro-waste extracts as a catalyst in the Knoevenagel condensation. The present protocol proceeds efficiently for various substituted aromatic and heterocyclic aldehydes in the Knoevenagel reactions. In addition, the present method describes direct isolation of the formed products without using organic solvent extraction gave good yields product.

scholarly journals Layered double hydroxide anchored ionic liquids as amphiphilic heterogeneous catalysts for the Knoevenagel condensation reaction

2018 ◽  
Vol 47 (9) ◽  
pp. 3059-3067 ◽  
Author(s):  
Tengfei Li ◽  
Wei Zhang ◽  
Wei Chen ◽  
Haralampos N. Miras ◽  
Yu-Fei Song
Keyword(s):  
Heterogeneous Catalysts ◽  
Knoevenagel Condensation ◽  
Condensation Reaction ◽  
Knoevenagel Reaction ◽  
Solid Base ◽  
Solid Base Catalysts ◽  
Base Catalysts ◽  
Excellent Activity ◽  
Knoevenagel Condensation Reaction ◽  
Double Hydroxide

In this paper, three solid base catalysts of LDH-IL-Cn (n = 4, 8, 12) were synthesized by adopting an exfoliation/assembly approach. The as-prepared catalyst showed excellent activity and selectivity for the Knoevenagel reaction in aqueous solution.

Mechanism and free energy profile of base-catalyzed Knoevenagel condensation reaction

RSC Advances ◽  
2016 ◽  
Vol 6 (63) ◽  
pp. 57803-57810 ◽  
Author(s):  
Ellen V. Dalessandro ◽  
Hugo P. Collin ◽  
Marcelo S. Valle ◽  
Josefredo R. Pliego
Keyword(s):  
Free Energy ◽  
Theoretical Calculation ◽  
Knoevenagel Condensation ◽  
Condensation Reaction ◽  
Knoevenagel Reaction ◽  
Energy Profile ◽  
Hydroxide Ion ◽  
Free Energy Profile ◽  
Knoevenagel Condensation Reaction

A reliable theoretical calculation of the free energy profile of a base-catalyzed Knoevenagel reaction shows that hydroxide ion elimination step is rate determining.

scholarly journals Solvent-free Knoevenagel reaction catalysed by reusable pyrrolidinium base protic ionic liquids (PyrrILs): synthesis of long-chain alkylidenes

RSC Advances ◽  
2017 ◽  
Vol 7 (6) ◽  
pp. 3214-3221 ◽  
Author(s):  
R. C. M. Alves Sobrinho ◽  
P. M. de Oliveira ◽  
C. R. Montes D'Oca ◽  
D. Russowsky ◽  
M. G. Montes D'Oca
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Knoevenagel Condensation ◽  
Condensation Reaction ◽  
Solvent Free ◽  
Knoevenagel Reaction ◽  
Protic Ionic Liquids ◽  
Knoevenagel Condensation Reaction ◽  
Pyrrolidinium Ionic Liquid ◽  
Long Chain

In this work, an efficient and reusable pyrrolidinium ionic liquid (PyrrIL) catalysis system was developed and used in a Knoevenagel condensation reaction of long-chain aldehydes with several 1,3-dicarbonyl compounds.

scholarly journals Synthesis, Characterization and Catalytic Potency of Zn-based MOF for Knoevenagel Condensation Reaction

2021 ◽  
Vol 9 (11) ◽  
pp. 730-735
Author(s):  
Vaishali N. Rathod
Keyword(s):  
Heterogeneous Catalyst ◽  
Present Method ◽  
Solvothermal Method ◽  
Knoevenagel Condensation ◽  
Condensation Reaction ◽  
Metal Organic Framework ◽  
Short Reaction Time ◽  
Metal Organic ◽  
Knoevenagel Condensation Reaction ◽  
Organic Framework

Abstract: A Zn based metal organic framework with pyridine 2, 5-dicarboxylate (Zn-based MOF) were prepared as a reusable heterogeneous catalyst using solvothermal method. Zn-based MOF was used as heterogeneous catalyst for synthesis 5-arylidene malononitrile in ethanol under reflux condition. The attractive features of present method are mild reaction condition, short reaction time, simplicity, easy separation of catalyst and excellent yield. Keywords: Metal organic framework, heterogeneous catalyst, solvothermal method.

STUDIES ON A NON-MELATONIN PINEAL ANTI-GONADOTROPHIN

1972 ◽  
Vol 69 (2) ◽  
pp. 257-266 ◽  
Author(s):  
Bryant Benson ◽  
Mary Jane Matthews ◽  
Alvin E. Rodin
Keyword(s):  
Solvent Extraction ◽  
Organic Solvent ◽  
Pineal Gland ◽  
Gel Filtration ◽  
Test System ◽  
Pineal Body ◽  
Physiological Effects ◽  
Organic Solvent Extraction ◽  
Gland Function

ABSTRACT Continuing investigation of pineal gland function indicates that the anti-gonadotrophic activity of this organ cannot be attributed solely to the postulated hormone melatonin, the concentration of which is negligible in the pineal body compared to quantities required to produce unequivocal physiological effects. A non-melatonin antigonadotrophic substance recently isolated from bovine pineal glands was further purified by organic solvent extraction, ultrafiltration and gel filtration. Studies of partial blockage of compensatory ovarian hypertrophy in unilaterally ovariectomized Charles River CD-1 mice indicated that this substance is significantly more potent than melatonin in this test system.

Facile fractionation of bamboo hydrolysate and characterization of isolated lignin and lignin-carbohydrate complexes

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Xiaodi Wang ◽  
Yongchao Zhang ◽  
Luyao Wang ◽  
Xiaoju Wang ◽  
Qingxi Hou ◽  
...  
Keyword(s):  
Solvent Extraction ◽  
Organic Solvent ◽  
Extraction Process ◽  
Water Soluble ◽  
Organic Solvent Extraction ◽  
Glycoside Linkage ◽  
Potential Applications ◽  
Tremendous Amount ◽  
Main Components ◽  
Hemicellulosic Sugars

AbstractAn efficient separation technology for hydrolysates towards a full valorization of bamboo is still a tough challenge, especially regarding the lignin and lignin-carbohydrate complexes (LCCs). The present study aimed to develop a facile approach using organic solvent extraction for efficiently fractionating the main components of bamboo hydrolysates. The high-purity lignin with only a trace of carbohydrates was first obtained by precipitation of the bamboo hydrolysate. The water-soluble lignin (WSL) fraction was extracted in organic solvent through a three-stage organic solvent extraction process, and the hemicellulosic sugars with increased purity were also collected. Furthermore, a thorough characterization including various NMR techniques (31P, 13C, and 2D-HSQC), GPC, and GC-MS was conducted to the obtained lignin-rich-fractions. It was found that the WSL fraction contained abundant functional groups and tremendous amount of LCC structures. As compared to native LCC of bamboo, the WSL fraction exhibited more typical LCC linkages, i.e. phenyl glycoside linkage, which is the main type of chemical linkage between lignin and carbohydrate in both LCC samples. The results demonstrate that organic phase extraction is a highly efficient protocol for the fractionation of hydrolysate and the isolation of LCC-rich streams possessing great potential applications.

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