Green Synthetic Methodology of (E)-2-cyano-3-aryl Selective Knoevenagel Adducts Under Microwave Irradiation

2019 ◽  
Vol 6 (1) ◽  
pp. 54-60 ◽  
Author(s):  
David Esteban Quintero Jimenez ◽  
Lucas Lima Zanin ◽  
Luan Farinelli Diniz ◽  
Javier Ellena ◽  
André Luiz Meleiro Porto
Keyword(s):  
Organic Chemistry ◽  
Microwave Irradiation ◽  
Organic Synthesis ◽  
Knoevenagel Condensation ◽  
Green Solvents ◽  
Nacl Solution ◽  
Synthetic Methodology ◽  
X Ray ◽  
Basic Catalysts ◽  
High Yields

Background: The Knoevenagel condensation is an important reaction in organic chemistry because of its capacity to form new C-C bonds and its products are mainly used in organic synthesis as intermediates, due to the large number of reactions they can undergo. Based on the importance of the Knoevenagel adducts, a sustainable synthetic methodology was developed employing microwave irradiation. Objective: Develop a synthetic methodology employing microwave irradiation and green solvents to obtain Knoevenagel adducts with high yields. Methods: Knoevenagel condensation reactions were evaluated with different basic catalysts, as well as in the presence or absence of microwave irradiation. The scope of the reaction was expanded using different aldehydes, cyanoacetamide or methyl cyanoacetate. The geometry of the formed products was also evaluated. Results: After the optimization process, the reactions between aldehydes and cyanoacetamide were performed with triethylamine as catalyst, in the presence of microwave irradiation, in 35 minutes, using NaCl solution as solvent and resulted in high yields 90-99%. The reactions performed between aldehydes and methyl cyanoacetate were also performed under these conditions, but showed better yields with EtOH as solvent 70-90%. Finally, from X-ray analysis, the (E)-geometry of these compounds was confirmed. Conclusion: In this study we developed synthetic methodology of Knoevenagel condensation using triethylamine, green solvents and microwave irradiation. In 35 minutes, products with high yields (70- 99%) were obtained and the (E)-geometry of the adducts was confirmed.

scholarly journals Friedel-Crafts benzoylation reaction of aromatic compounds using zinc oxide nanoparticles in deep eutectic solvent (choline chloride/urea) under microwave irradiation

2019 ◽  
Vol 2 (2) ◽  
pp. 62-70
Author(s):  
Hai Truong Nguyen ◽  
Dung Thi Kim Ngo ◽  
Thinh Nguyen Huu Pham ◽  
Phuong Hoang Tran
Keyword(s):  
Zinc Oxide ◽  
Microwave Irradiation ◽  
Aromatic Compounds ◽  
Zinc Oxide Nanoparticles ◽  
Choline Chloride ◽  
Deep Eutectic Solvent ◽  
Reaction Times ◽  
Oxide Nanoparticles ◽  
X Ray ◽  
High Yields

Synthesis of zinc oxide nanoparticles (ZnO) which was found to be effective catalyst for Friedel-Crafts benzoylation reaction in the presence of deep eutectic solvent (DES). The method is one of the most important intermediates for preparing fine chemicals in the field of pharmaceuticals, which is a tool for organic syntheses of aromatic ketones. ZnO precursor was prepared from Zn(CH3COO)2.2H2O and H2C2O4.2H2O, ZnO nanoparticles were characterized by using X-ray Powder Diffraction (XRD), Scanning Electron Microscope (SEM). The benzoylation of aromatic compounds and benzoyl chloride using nanoparticles ZnO/ [CholineCl][Urea]2, under microwave irradiation afforded the desired products in high yields and short reaction times. The catalyst/solvent could be recycled several times without loss of efficient catalytic activity.

Synthesis and Crystal Structure of (1E,2E)-1,2-Di (-3-Nitrobenzylidene) Hydrazine under Micromave Irradiation

2013 ◽  
Vol 787 ◽  
pp. 205-207
Author(s):  
Hong Yan Zhou
Keyword(s):  
Crystal Structure ◽  
Microwave Irradiation ◽  
Monoclinic Space Group ◽  
Stacking Interactions ◽  
X Ray Diffraction ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
H Nmr ◽  
The Stability ◽  
High Yields

A compound of (1E,2E)-1,2-di (-3-nitrobenzylidene) hydrazine was synthesized under microwave irradiation (500 w), giving high yields of products (93%). Its structure was determined IR, 1H NMR, MS, elemental analysis and X-ray diffraction. The crystal of the compound is Monoclinic, space group P2(1)/n with a = 6.9611(18), b = 7.823(2), c = 12.999(3) Å, α = 90, β = 105.215(4), γ = 90o, V= 683.1(3) Å3, Z=4, Dc=1.450g/cm3,μ=0.110 mm-1, F(000)=308, R=0.0401 and wR = 0.1131 for 1273 observed reflection with I>2σ (I). π-π stacking interactions contribute to the stability of the structure.

scholarly journals Synthesis of 2,24-Diene-12,13,15,16,34,35,37,38-octaphenyl[4.4]triphenylparacyclophane

Synthesis ◽  
2021 ◽  
Author(s):  
Duy H. Hua ◽  
Bernard Wiredu ◽  
Mahendra Thapa ◽  
Sheen Y. Hua ◽  
John Desper
Keyword(s):  
Olefin Metathesis ◽  
Knoevenagel Condensation ◽  
Coupling Reaction ◽  
Diels Alder ◽  
Synthetic Methodology ◽  
X Ray ◽  
X Ray Crystallography ◽  
Vinyl Group ◽  
Synthetic Intermediate

AbstractA new octaphenyl[4.4]triphenylparacyclophanediene was readily synthesized in six steps from p-xylene via the installment of bromine atoms, replacement with a vinyl group, carbonylative coupling, intermolecular followed by intramolecular double Grubbs olefin metathesis, Knoevenagel condensation, and Diels–Alder cycloaddition. The belt-shaped structure and trans-stereochemistry of the alkene moieties of the octaphenyl[4.4]triphenylparacyclophane and a synthetic intermediate, 2,21-dioxo-11,30-diene[3.4.3.4]paracyclophane, were determined by X-ray crystallography. The synthetic methodology leading to octaphenyl[4.4]triphenylparacyclophane is applicable for the synthesis of substituted triphenylparacyclophanes and possibly their corresponding bis-hexabenzocoronenylparacyclophanes via a Scholl–Mullen oxidative aryl-aryl coupling reaction.

scholarly journals [DBN][HSO4]-Promoted facile and green synthesis of 2-Amino-4H-pyrans derivatives under microwave irradiation

2021 ◽  
Vol 11 (2-S) ◽  
pp. 89-97
Author(s):  
Vishal Mane ◽  
Dhanjay Mane
Keyword(s):  
Ionic Liquid ◽  
Microwave Irradiation ◽  
Room Temperature ◽  
Knoevenagel Condensation ◽  
Reaction Times ◽  
Environmentally Benign ◽  
Successive Reaction ◽  
Solvent Free Conditions ◽  
High Yields ◽  
First Time

The [DBN][HSO4] -promoted Knoevenagel condensation followed by cyclization protocol has been developed for the first time by a successive reaction of aldehydes, dimedone and malononitrile to afford 2-Amino-4H-pyrans derivatives in high to excellent yields at room temperature. The synergic couple of microwave and ionic liquid provided the capability to allow a variability of functional groups, short reaction times, easy workup, high yields, recyclability of the catalyst, and solvent-free conditions, thus providing economic and environmental advantages. Keywords: [DBN][HSO4], Environmentally benign, 2-Amino-4H-pyrans, Knoevenagel condensation, Microwave irradiation

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 Chiral Binaphthalenes Bearing Two Pyridine Ligands Attached Via Acetylene Spacers. Synthesis and Coordination Study

2007 ◽  
Vol 72 (8) ◽  
pp. 1139-1157 ◽  
Author(s):  
Peter Kasák ◽  
Henrich Brath ◽  
Katarína Krascsenicsová-Poláková ◽  
Anna Kicková ◽  
Natalia Moldovan ◽  
...  
Keyword(s):  
Microwave Irradiation ◽  
Good Yield ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Cd Spectroscopy ◽  
X Ray ◽  
Pyridine Ligands ◽  
Cross Coupling Reaction ◽  
Coordination Ability ◽  
High Yields

An effective methodology has been developed for the synthesis of enantiopure 2,2'-dialkynylated 1,1'-binaphthalene derivatives. Enantiopure 2,2'-diiodo-1,1'-binaphthalene (10) provided 2,2'-diethynyl-1,1'-binaphthalene (16) in the Negishi alkynylation supported by microwave irradiation in a very good yield with conservation of stereochemical information. The Stephen-Castro alkynylation of 10 afforded products in lower yields; however, in stereoconservative manner as well. Terminal diacetylene 16 served as precursor in the Sonogashira cross-coupling reaction to give new bispyridine derivatives 7-9 as potential ligands in moderate to high yields. Coordination of bispyridines with Zn2+ and Ag+ ions was observed by NMR and CD spectroscopy. The coordination ability of bis(2-pyridylethynyl) derivative 7 to palladium cation was determined by X-ray structure analysis.

scholarly journals Review: Microwave-Promoted Organic Synthesis

2009 ◽  
Vol 8 (2 and 3) ◽  
Author(s):  
Andrew Loftin ◽  
Douglas Armstrong
Keyword(s):  
Organic Chemistry ◽  
Organic Synthesis ◽  
Efficient Method ◽  
Side Reactions ◽  
New Wave ◽  
Different Types ◽  
The Many ◽  
High Yields ◽  
Short Time ◽  
The Way

As of the last twenty years a new wave in organic chemistry has started to change the way people think about putting energy into a reaction mixture. Microwave-promoted organic synthesis is a fast, efficient method of heating a system in order to achieve the completion of a desired reaction. There are many different types of reactions that have been attempted using this method, and still many more to be tested. Microwave-promoted organic synthesis can help to produce high yields of products in a short time, while reducing side reactions and making workups easier. This paper discusses the many benefits of microwave-promoted organic synthesis and gives various examples.

scholarly journals Multi-component reaction between aromatic aldehyde, ethyl acetoacetate and urea catalyzed by Brönsted ionic liquid under microwave irradiation

2019 ◽  
Vol 2 (3) ◽  
pp. 68-77
Author(s):  
Hai Truong Nguyen ◽  
Nguyen Thi Thanh Huynh ◽  
Phuong Hoang Tran
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Ionic Liquid ◽  
Catalytic Activity ◽  
Microwave Irradiation ◽  
Organic Synthesis ◽  
Short Reaction Time ◽  
Ionisation Mass Spectrometry ◽  
High Yields ◽  
Ionisation Mass

[(SO3H)4C4C1Im]HSO4 is a Brönsted ionic liquid, which was found to be an effective catalyst for organic synthesis. Ionic liquid was prepared from 1-methylimidazole and 1,4- butanesultone (ratio = 1:1), structure of [(SO3H)4C4C1Im]HSO4 was characterized by using nuclear magnetic resonance NMR spectroscopy and high-resolution electrospray ionisation mass spectrometry (HR-ESI-MS). Ionic liquid was used as a catalyst for multi-component reaction, which afforded the desired products in high yields (over 80%) and short reaction time (5 min) under microwave irradiation. The catalyst could be recycled several times without loss of efficient catalytic activity.

A Synthesis of Novel Perinaphthenones from Acetylenic Esters and Acenaphthoquinone–Malononitrile Adduct in the Presence of Triphenylphosphine

Synlett ◽  
2018 ◽  
Vol 29 (15) ◽  
pp. 2011-2014
Author(s):  
Issa Yavari ◽  
Aliyeh Khajeh-Khezri ◽  
Mohammad Halvagar
Keyword(s):  
Knoevenagel Condensation ◽  
Condensation Product ◽  
Ethyl Cyanoacetate ◽  
Selective Synthesis ◽  
Atom Economy ◽  
Acetylenic Esters ◽  
X Ray ◽  
X Ray Crystallography ◽  
Catalytic Role ◽  
High Yields

A facile protocol involving Tebby zwitterions (PPh3-acetylenic esters) and the Knoevenagel condensation product of acenaphthylene-1,2-dione with malononitrile or ethyl cyanoacetate for the selective synthesis of a new series of perinaphthenone derivatives is described. Triphenylphosphine plays a catalytic role in these transformations. The structure of a typical product was confirmed by X-ray crystallography. The merits of this method include high yields of products, good atom economy, and a metal-free catalyst.

Eco-Friendly Synthesis of Pyrazoline Derivatives

2017 ◽  
Vol 9 (04) ◽  
Author(s):  
Mahesh G. Kharatmol ◽  
Deepali Jagdale
Keyword(s):  
Ionic Liquids ◽  
Microwave Irradiation ◽  
Organic Synthesis ◽  
Ultrasonic Irradiation ◽  
Minimal Energy ◽  
Anticancer Activities ◽  
Conventional Methods

Pyrazoline class of compounds serve as better moieties for an array of treatments, they have antibacterial, antifungal, antiinflammatory, antipyretic, diuretic, cardiovascular activities. Apart from these they also have anticancer activities. So, pertaining to its importance, many attempts are made to synthesize pyrazolines. Since conventional methods of organic synthesis are energy and time consuming. There are elaborate pathways for green and eco-friendly synthesis of pyrazoline derivatives including microwave irradiation, ultrasonic irradiation, grinding and use of ionic liquids which assures the synthesis of the same within much lesser time and by use of minimal energy

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