Finkelstein Reaction in Functionalized Crown-ether Ionic Liquids

Recent years, crown ethers have been used in many fields, including phase transfer catalysis, chromatography stationary phase, ionselective electrode, and concentration of metal ions, etc1.. However, the toxicity of free crown ethers makes them unsuitable for industrial use2. Introduction of a crown ether as a functional group to functionalized ionic liquids has been reported3. These functionalized ionic liquids will combine the excellent properties of crown ether and ionic liquids without los…     

Green Synthesis of Pyrano[2,3‐d]‐pyrimidine Derivatives in Ionic Liquids

Pyrano[2,3‐d]pyrimidine derivatives were synthesized in high yields by a condensation reaction between arylmethylidenemalononitrile and barbituric acid using room‐temperature ionic liquids such as 1‐n‐butyl‐3‐methylimidazolium tetrafluoroborate ([BMIm]BF₄) or 1‐butylpyridinium tetrafluoroborate ([BPy]BF₄) as solvents under neutral conditions.     

Organic Reactions in Ionic Liquids: Ionic Liquid‐Accelerated One‐Pot Synthesis of 2‐Arylimidazo[1,2‐a]pyrimidines

Abstract

The room‐temperature ionic liquid n‐butylpyridinium tetrafluoroborate (BPyBF₄) is used as a recyclable alternative to classical molecular solvents in the one‐pot synthesis of 2‐arylimidazo[1,2‐a]pyrimidines by reaction with ketones, [hydroxy(tosyloxy)iodo]benzene, and 2‐aminopyrimidine. Significant rate enhancements and improved yields have been observed.     

Synthesis and Characterization of the First Pyrrolidine‐Based Chiral Ionic Liquids

The first example of pyrrolidine‐based room‐temperature chiral ionic liquids using 2‐aminobutanol as chiral auxiliary is described.     

Synthesis of Multiester-appended and Multicarboxylic-appended Imidazolium Ionic Liquids

Currently ionic liquids (ILs) are attracting considerable interest as eco-friendly solventsfor the replacement of volatile organic solvents in organic synthesis and catalysis1.Low-melting ILs based on imidazolium cations have dominated this area over the …     

Synthesis and Characterization of Dual Acidic Ionic Liquids

Novel ionic liquids with dual acidity, of which the cation contains Brφnsted acidity and anions contain Lewis acidity were synthesized. These ionic liquids obtained were identified by NMR, FF-IR, SDT and FAB-MS. Their acidities were determined by pyridine probe on IR spectrography.     

Facile Synthesis of 4‐Functionalized Cyclopentenones

1-8-Diazabicyclo[5.4.0]undec-7-ene(DBU)‐catalyzed Michael addition of nitroalkanes to dicyclopentadienone (1) followed by flash vacuum pyrolysis (FVP) provided a high‐yielding synthesis of extremely pure 4‐nitroalkyl cyclopentenones (3). The optimized Nef reaction of the nitro adducts (2) provided 4‐ketoalkyl cyclopentenones (5) in the similar way.     

Synthesis of Polymer-Bonded Quaternary Ammonium Type Metal Porphyrins

Synthetic metalloporphyrin are efficient models of the cytochrome P-450 family ofmono-oxygen enzymes and have been largely used as catalysts in oxidation of alkanesand epoxidation of alkenesl. Polymer-bonded metalloporphyrin reveal many advantageson the catalytic reaction, where the catalysts can be easily separated from the products,recovered, and reused2. Quaternary ammonium salts as phase transfer catalysts werewide used in aqueous-organic two-phase conditions. Unfortunately, most porphyrin…     

Metal Sulfide Nanoparticle Synthesis with Ionic Liquids – State of the Art and Future Perspectives

Metal sulfides are among the most promising materials for a wide variety of technologically relevant applications ranging from energy to environment and beyond. Incidentally, ionic liquids (ILs) have been among the top research subjects for the same applications and also for inorganic materials synthesis. As a result, the exploitation of the peculiar properties of ILs for metal sulfide synthesis could provide attractive new avenues for the generation of new, highly specific metal sulfides for numerous applications. This article therefore describes current developments in metal sulfide nanoparticle synthesis as exemplified by a number of highlight examples. Moreover, the article demonstrates how ILs have been used in metal sulfide synthesis and discusses the benefits of using ILs over more traditional approaches. Finally, the article demonstrates some technological challenges and how ILs could be used to further advance the production and specific property engineering of metal sulfide nanomaterials, again based on a number of selected examples.     

Organic Reactions in Ionic Liquids： Ionic Liquid-promoted Efficient Synthesis of Disubstituted and Trisubstituted Thioureas Derivatives

In ionic liquid [Bmim][BF4], a series of disubstituted and trisubstituted thiourea derivatives were synthesized from phenyl and butyl isothiocyanate with a variety of amine in excellent yield.     

Efficient Esterification of Ferrocenecarboxylic Acid in Ionic Liquids

An efficient esterification of ferrocenecarboxylic acid with substituted phenols has been achieved using DCC / DMAP protocol in ionic liquids. The corresponding esters are produced in high yields.     

One-pot Synthesis of Lewis Acidic Ionic Liquids for Friedel-Crafts Alkylation

Lewis acidic ionic liquids have been receiving extensive interest as green substitute for H2SO4, HF and AlCl3 catalysts in chemical processes1. In view of the principles of green chemistry2, ionic liquids themselves are highly expected to be obtained via …     

Practical Synthesis of Functionalized 2‐Thioxoimidazolidine Derivatives

High‐yielding syntheses of an unpublished series of 2‐thioxo‐imidazolidin‐4‐ones 6 bearing an N‐ethoxycarbonyl and amidyl moieties an N₁ and C₅, respectively, are reported. These derivatives were obtained by intramolecular cyclization of 3‐ethylhydrazinoacetate 3,4‐dihydro maleimides 4 in the presence of ethyl or phenylisothiocyanate 2 under neutral conditions.     

Microwave‐Assisted Efficient Synthesis of Dihydropyrimidines in Solvent‐Free Condition

Abstract

An efficient synthesis of 3,4‐dihydropyrimidinones from an aldehyde, a ketoester, and a urea or thiourea using a catalytic amount of ferric chloride hexahydrate is described. Microwave irradiation has been used to accelerate the synthesis of the Biginelli compounds under solvent‐free conditions and in a short reaction time and with good yield.     

A Novel Green Synthesis of Quinolines through Acid-catalyzed Friedlander Reaction in Ionic Liquids

Quinoline derivatives were efficiently prepared through acid-catalyzed Friedlander reaction in ionic liquid ([bmim] [BF4]). It is shown that the proposed method is operationally simple and environmentally benign in that the reaction media and the catalyst can be recovered and be reused effectively for at least four times.     

Solvent‐Free Synthesis of Benzothiazolines in the Presence of Alumina

o‐Aminothiophenol reacted with ketones and β‐keto esters in the presence of alumina under mild and solvent‐free conditions to afford the corresponding benzothiazolines in high yields. Alumina can be reused for subsequent reactions without any loss of the activity.     

Palladium‐Catalyzed Enyne Cyclization of 2′‐Alkenyl 2‐Alkynoates in Imidazolium‐Type Ionic Liquids

The use of [bmim][BF₄], [bmim][PF₆], and [bmim][Cl] ILs as the solvents in Pd(II)‐catalyzed enyne cyclization of 2′‐alkenyl 2‐alkynoates in the presence of cupric chloride has been investigated. The Z/E stereoselectivity of the reaction could range from 90:10 to 4:96 by tuning the amount of LiCl in ILs. After the separation of the product, the IL–catalyst mixture could be recovered by treatment with hydrochloric acid and recycled several times without an obvious loss of catalytic activity.     

Synthesis of 2-Arylimidazo[1, 2-a]pyrimidines in Ionic Liquids

Room temperature ionic liquids were used as a “green“ recyclable alternative to conventional solvents in the synthesis of pharmaceutically useful compounds 2-arylimidazo[1, 2-a]pyrimidines through Tschotschibabin reaction of a-bromoacetophenones with 2-aminopyrimidine in good yields.     

Synthesis and Characterization of Task‐Specific Ionic Liquids Possessing Two Brönsted Acid Sites

Abstract

Task‐specific ionic liquids possessing two Brönsted acid sites with –COOH, HSO^? ₄, or H₂PO^? ₄ groups have been designed, synthesized, and characterized. Under mild conditions and without any additional organic solvent, the esterification of isopropanol by chloroacetic acid could be carried out in these new task‐specific ionic liquids. In comparison with most of acidic ionic liquids in current use, these ionic liquids are halogen free and more environmentally benign as media and catalysts.