Ionic Liquid as Catalyst and Reaction Medium – A Simple, Efficient and Green Procedure for Knoevenagel Condensation of Aliphatic and Aromatic Carbonyl Compounds Using a Task‐Specific Basic Ionic Liquid

Ranu, Brindaban C.; Jana, Ranjan

doi:10.1002/ejoc.200600335

Cited by 209 publications

(57 citation statements)

References 60 publications

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“…The catalysts traditionally used for this reaction are ammonia, or primary or secondary amines. 21 In recent years, a wide range of catalysts and promoters such as NbCl TMSCl 27 and ionic liquids [28][29][30] have been employed to catalyze this reaction in solution or under solvent-free conditions. In spite of the aforementioned efforts for the synthesis of α,β-unsaturated compounds, many of these methods involve expensive reagents, strong acidic/basic conditions, long reaction times, low yields and use of toxic organic solvents, reagents or catalysts.…”

Section: -8mentioning

confidence: 99%

Immobilization of L-Lysine on Zeolite 4A as an Organic-Inorganic Composite Basic Catalyst for Synthesis of α,β-Unsaturated Carbonyl Compounds under Mild Conditions

Zamani¹,

Rezapour²,

Kianpour³

2013

Bulletin of the Korean Chemical Society

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Lysine (Lys) immobilized on zeolite 4A was prepared by a simple adsorption method. The physical and chemical properties of Lys/zeolite 4A were investigated by X-ray diffraction (XRD), FT-IR, BrunauerEmmett-Teller (BET), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and UV-vis. The obtained organic-inorganic composite was effectively employed as a heterogeneous basic catalyst for synthesis of α,β-unsaturated carbonyl compounds. No by-product formation, high yields, short reaction times, mild reaction conditions, operational simplicity with reusability of the catalyst are the salient features of the present catalyst.

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Section: -8mentioning

confidence: 99%

Immobilization of L-Lysine on Zeolite 4A as an Organic-Inorganic Composite Basic Catalyst for Synthesis of α,β-Unsaturated Carbonyl Compounds under Mild Conditions

Zamani¹,

Rezapour²,

Kianpour³

2013

Bulletin of the Korean Chemical Society

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“…For cyclic final products, AE augments with increasing ring size. [51] If a reaction is carried out under nonstoichiometric conditions, some corrections must be made to calculate the RME. …”

Section: Additionsmentioning

confidence: 99%

Sustainable Chemistry Metrics

Calvo‐Flores

2009

ChemSusChem

129

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Green chemistry has developed mathematical parameters to describe the sustainability of chemical reactions and processes, in order to quantify their environmental impact. These parameters are related to mass and energy magnitudes, and enable analyses and numerical diagnoses of chemical reactions. The environmental impact factor (E factor), atom economy, and reaction mass efficiency have been the most influential metrics, and they are interconnected by mathematical equations. The ecodesign concept must also be considered for complex industrial syntheses, as a part of the sustainability of manufacturing processes. The aim of this Concept article is to identify the main parameters for evaluating undesirable environmental consequences.

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“…[3][4][5][6][7][8][9] Particularly, the use of [bmIm]OH as a novel and a recyclable reaction medium, as well as an efficient catalyst for Knoevenagel and Michael reactions has been reported in literature. [10][11][12] Similarly, 1-methyl imidazolium tetrafluoroborates has been exploited as an efficient Bronsted acid promoter ionic liquid in various organic transformations. [13][14][15] As a part of our study on environmentally friendly organic synthesis with isoxazoles, [16][17][18][19] avoiding organic solvent and toxic catalyst in reactions, we demonstrated the use of room temperature ionic liquids as efficient catalysts as well as reaction media for Knoevenagel and Michael reactions and also for conducting reductive cyclization.…”

Section: Regular Articlementioning

confidence: 99%

A Fast and Highly Efficient Protocol for Synthesis of Pyrrolo[2,3-d]isoxazoles and a New Series of Novel Benzyl Bis-pyrrolo[2,3-d]isoxazoles Using Task-Specific Ionic Liquids as Catalyst and Green Solvent

et al. 2010

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Regular ArticleSignificant progress in green chemistry is being made in several key research areas, such as catalysis, 1) the design of safer chemicals, environmentally benign solvents 2) and the development of renewable feed stocks. Chemists are trained to design products and processes with an increased awareness of environmental impact. Outreach activities within the green chemistry community highlight the potential for chemistry to solve many of the global environmental challenges. In the recent years, ionic liquids have emerged as green solvents with desirable properties such as good solvating ability, wide liquidous range, tunable polarity, high thermal stability, negligible vapour pressure and ease of recyclability. These are referred to as designer solvents since they exhibit properties like hydrophilicity, hydrophobicity, Lewis acidity, viscosity and density. These can be altered by the fine tuning of parameters such as the choice of organic cation and the length of alkyl chain attached to an organic cation. These structural variations offer flexibility to the chemists to devise the most idealized solvent catering to the needs of any particular process. Due to the stabilization of charged intermediates by ionic liquids, they can promote unprecedented selectivities and enhanced reaction rates. Consequently, ionic liquids are being used as recyclable solvents for the immobilization of transition metal-based catalysts, Lewis acids and enzymes. During the past few years, a variety of room temperature ionic liquids have been demonstrated as efficient and practical alternatives to organic solvents for many important organic transformations. [3][4][5][6][7][8][9] Particularly, the use of [bmIm]OH as a novel and a recyclable reaction medium, as well as an efficient catalyst for Knoevenagel and Michael reactions has been reported in literature. [10][11][12] Similarly, 1-methyl imidazolium tetrafluoroborates has been exploited as an efficient Bronsted acid promoter ionic liquid in various organic transformations. [13][14][15] As a part of our study on environmentally friendly organic synthesis with isoxazoles, [16][17][18][19] avoiding organic solvent and toxic catalyst in reactions, we demonstrated the use of room temperature ionic liquids as efficient catalysts as well as reaction media for Knoevenagel and Michael reactions and also for conducting reductive cyclization.Looking for a valuable procedure for the conversion of nitro styrylisoxazoles (3) to pyrrolo[2,3-d]isoxazoles (4), several approaches have been investigated. One method for pyrrole ring formation is by de-oxygenative cyclization of nitro styryl compounds using triethyl phosphite (TEP). [20][21][22] As the reaction requires heating of the nitro styrylisoxazole (3) in TEP at high temperature under N 2 atmosphere, the reaction results in cleavage of the isoxazole ring, which is unstable at higher temperature. 23) To overcome this problem, another method developed by Angelo Carotti 24) is employed, which involves the reductive cyclization of a nitro s...

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Ionic Liquid as Catalyst and Reaction Medium – A Simple, Efficient and Green Procedure for Knoevenagel Condensation of Aliphatic and Aromatic Carbonyl Compounds Using a Task‐Specific Basic Ionic Liquid

Cited by 209 publications

References 60 publications

Immobilization of L-Lysine on Zeolite 4A as an Organic-Inorganic Composite Basic Catalyst for Synthesis of α,β-Unsaturated Carbonyl Compounds under Mild Conditions

Immobilization of L-Lysine on Zeolite 4A as an Organic-Inorganic Composite Basic Catalyst for Synthesis of α,β-Unsaturated Carbonyl Compounds under Mild Conditions

Sustainable Chemistry Metrics

A Fast and Highly Efficient Protocol for Synthesis of Pyrrolo[2,3-d]isoxazoles and a New Series of Novel Benzyl Bis-pyrrolo[2,3-d]isoxazoles Using Task-Specific Ionic Liquids as Catalyst and Green Solvent

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