Ionic Liquid Supports Stable Under Conditions of Peptide Couplings, Deprotections and Traceless Suzuki Reactions

2007 ◽  
Vol 72 (3) ◽  
pp. 417-434 ◽  
Author(s):  
Zoia Mincheva ◽  
Fabien Bonnette ◽  
Olivier Lavastre
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Cross Coupling ◽  
Amino Groups ◽  
Peptide Chemistry ◽  
Suzuki Reactions ◽  
Coupling Conditions ◽  
Pyridinium Cations

Ionic liquid supports (ILS) functionalized with carboxylic, alcoholic or amino groups were synthesized, based on 1-methylimidazolium and pyridinium cations, and bromide, chloride, iodide and tetrafluoroborate anions. These reactive ionic liquids were fully characterized by NMR and HRMS. Ionic liquids based on 1-(6-aminohexyl)-3-methylimidazolium iodide have been used in the conditions of peptide chemistry such as coupling and deprotection reactions. A method for attaching (bromophenyl)silanes to the ionic liquid supports was also developed to introduce traceless linkers. An ionic liquid with attached bromobenzene was reacted with ArB(OH)2 under the Suzuki cross-coupling conditions and the resulting compound was cleaved by bromodesilylation with Br2/pyridine to give the substituted products in good yields. The substrate loading of the ILS is high and can be tuned to between 2.5 and 5.0 mmol/g.

Ionophilic phosphonium-appended carbopalladacycle catalyst for Suzuki–Miyaura and Heck cross-coupling catalysis

2010 ◽  
Vol 88 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Jocelyn J. Tindale ◽  
Paul J. Ragogna
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Catalyst Activity ◽  
Reaction Medium ◽  
Cross Coupling ◽  
Metal Catalyst ◽  
Phosphonium Salts ◽  
Transition Metal Catalyst ◽  
Imidazolium Ionic Liquids ◽  
Liquid Reaction

An ionic liquid, covalently tethered to an efficient transition-metal catalyst in the presence of an ionic liquid reaction medium, can utilize ionophilic interactions to improve catalyst activity, recyclability, and product isolation while decreasing catalyst leaching. Given the greater stability of phosphonium salts in comparison to imidazolium ionic liquids under basic conditions, phosphonium-tagged oxime carbopalladacycle salts were prepared and employed in both Heck and Suzuki–Miyaura reactions. The desired product was obtained in good yields for up to four catalyst cycles in the case of the Suzuki–Miyaura reaction. While taking advantage of the non-volatile nature of ionic liquids, the product was isolated through simple sublimation from the reaction mixture, eliminating issues associated with catalyst leaching, and the remaining ionic liquid solvent–catalyst mixture was ready for further catalysis.

Ionic liquids in cross-coupling reactions: “liquid” solutions to a “solid” precipitation problem

2018 ◽  
Vol 54 (16) ◽  
pp. 2056-2059 ◽  
Author(s):  
Hemant Choudhary ◽  
Paula Berton ◽  
Gabriela Gurau ◽  
Allan S. Myerson ◽  
Robin D. Rogers
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Salt Precipitation ◽  
Solid Precipitation ◽  
Cross Coupling Reactions ◽  
Solid Salt ◽  
Liquid Solutions

To alleviate the problem of solid salt precipitation when using inorganic bases in cross-coupling reactions, basic anions were combined with the trihexyl(tetradecyl)phosphonium ([P66614]+) cation to ensure an ionic liquid byproduct.

scholarly journals Palladium-catalyzed Sonogashira coupling reactions in γ-valerolactone-based ionic liquids

2019 ◽  
Vol 15 ◽  
pp. 2907-2913 ◽  
Author(s):  
László Orha ◽  
József M Tukacs ◽  
László Kollár ◽  
László T Mika
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Reaction Medium ◽  
Cross Coupling ◽  
Environmental Efficiency ◽  
Coupling Reactions ◽  
Sonogashira Coupling ◽  
Mild Conditions ◽  
Palladium Catalyzed ◽  
Alternative Reaction Medium

It was demonstrated that the γ-valerolactone-based ionic liquid, tetrabutylphosphonium 4-ethoxyvalerate as a partially bio-based solvent can be utilized as alternative reaction medium for copper- and auxiliary base-free Pd-catalyzed Sonogashira coupling reactions of aryl iodides and functionalized acetylenes under mild conditions. Twenty-two cross-coupling products were isolated with good to excellent yields (72–99%) and purity (>98%). These results represent an example which proves that biomass-derived safer solvents can be utilized efficiently in common, industrially important transformations exhibiting higher chemical and environmental efficiency.

Enolboration of conjugated ketones and synthesis of beta-amino alcohols and boronated alpha-amino acids

2003 ◽  
Vol 75 (9) ◽  
pp. 1349-1355 ◽  
Author(s):  
M. Zaidlewicz ◽  
W. Sokól ◽  
A. Wolan ◽  
J. Cytarska ◽  
A. Tafelska-Kaczmarek ◽  
...  
Keyword(s):  
Amino Acids ◽  
Ionic Liquid ◽  
Ionic Liquids ◽  
Reaction Time ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Amino Alcohols ◽  
Enantioselective Synthesis ◽  
Enantioselective Reduction ◽  
Cross Coupling Reaction

Enolization–aldolization of conjugated ketones, enantioselective synthesis of benzofuryl beta-amino alcohols, and synthesis of p-dihydroxyborylphenylalanine (BPA) and its analogs are described. Aldolization of benzaldehyde with lithium dienolates derived from unhindered conjugated cyclohexenones favored anti- selectivity, whereas syn selectivity was favored for hindered cyclohexenones. Anti-aldols were preferentially formed from dienolborinates derived from conjugated cyklohexenones, however,competing aldolization at the 2-position was observed for hindered ketones. Benzofuryl beta-amino alcohols were prepared using as a key step the enantioselective reduction of the corresponding alpha-bromoacetylbenzofurans with (–)-B- -chlorodiisopinocampheylborane. Ionic liquids were used as solvents for the synthesis of BPA by the Suzuki cross-coupling reaction. The reaction time is short, and a solution of the catalyst in the ionic liquid can be recycled.

scholarly journals Tetrabutylphosphonium 4-ethoxyvalerate as a biomass-originated media for homogeneous palladium-catalyzed Hiyama coupling reactions

2020 ◽  
Vol 74 (12) ◽  
pp. 4593-4598
Author(s):  
László Orha ◽  
Ábrahám Papp ◽  
József M. Tukacs ◽  
László Kollár ◽  
László T. Mika
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Functional Group ◽  
Cross Coupling ◽  
Catalyst System ◽  
Catalyst Precursor ◽  
Coupling Reactions ◽  
Tetrabutylammonium Fluoride ◽  
Carbon Carbon Bonds ◽  
Palladium Catalyzed

Abstract The introduction of a biomass-derived ionic liquid into the Hiyama coupling reactions, which has been considered as a powerful tool for the synthesis of symmetrically and non-symmetrically substituted biaryl structures, could further control or even reduce the environmental impact of this transformation. It was shown that tetrabutylphosphonium 4-ethoxyvalerate, a γ-valerolactone-based ionic liquid, can be utilized as an alternative solvent to create carbon–carbon bonds between aryl iodides and functionalized organosilanes in the presence of 1 mol% Pd under typical Hiyama conditions (130 °C, 24 h, tetrabutylammonium fluoride activator). A comparison of different ionic liquids was performed, and the effects of the catalyst precursor and the moisture content of the reaction mixture on the activity of the catalyst system were investigated. The functional group tolerance was also studied, resulting in 15 cross-coupling products (3a–o) with isolated yields of 45–72% and excellent purity (> 98%).

Mapping the “Extra Solvent Power, ESP” of Ionic Liquids for Monomers, Polymers and Globular Nanoparticles

2017 ◽  
Author(s):  
Jose A. Pomposo
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Linear Polymers ◽  
Green Solvents ◽  
Ionic Polymers ◽  
First Time ◽  
Solvent Power

Understanding the miscibility behavior of ionic liquid (IL) / monomer, IL / polymer and IL / nanoparticle mixtures is critical for the use of ILs as green solvents in polymerization processes, and to rationalize recent observations concerning the superior solubility of some proteins in ILs when compared to standard solvents. In this work, the most relevant results obtained in terms of a three-component Flory-Huggins theory concerning the “Extra Solvent Power, ESP” of ILs when compared to traditional non-ionic solvents for monomeric solutes (case I), linear polymers (case II) and globular nanoparticles (case III) are presented. Moreover, useful ESP maps are drawn for the first time for IL mixtures corresponding to case I, II and III. Finally, a potential pathway to improve the miscibility of non-ionic polymers in ILs is also proposed.

Dynamics of Ion Locking in Doubly Polymerized Ionic Liquids

2020 ◽  
Author(s):  
Swati Arora ◽  
Julisa Rozon ◽  
Jennifer Laaser
Keyword(s):  
Dielectric Constant ◽  
Ionic Liquid ◽  
Ionic Liquids ◽  
Ion Pairs ◽  
Polymer Chains ◽  
Ion Motion ◽  
Charged Species ◽  
Broadband Dielectric Spectroscopy ◽  
Covalently Linked ◽  
Insight Into

<div>In this work, we investigate the dynamics of ion motion in “doubly-polymerized” ionic liquids (DPILs) in which both charged species of an ionic liquid are covalently linked to the same polymer chains. Broadband dielectric spectroscopy is used to characterize these materials over a broad frequency and temperature range, and their behavior is compared to that of conventional “singly-polymerized” ionic liquids (SPILs) in which only one of the charged species is attached to the polymer chains. Polymerization of the DPIL decreases the bulk ionic conductivity by four orders of magnitude relative to both SPILs. The timescales for local ionic rearrangement are similarly found to be approximately four orders of magnitude slower in the DPILs than in the SPILs, and the DPILs also have a lower static dielectric constant. These results suggest that copolymerization of the ionic monomers affects ion motion on both the bulk and the local scales, with ion pairs serving to form strong physical crosslinks between the polymer chains. This study provides quantitative insight into the energetics and timescales of ion motion that drive the phenomenon of “ion locking” currently under investigation for new classes of organic electronics.</div>

Ionic Liquid Assisted Synthesis of Some 2-Aminobenzenethiols

2019 ◽  
Vol 16 (7) ◽  
pp. 550-555
Author(s):  
Dinesh K. Jangid ◽  
Keshav L. Ameta ◽  
Surbhi Dhadda ◽  
Anjali Guleria ◽  
Prakash G. Goswami ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Comparative Study ◽  
Maximum Yield ◽  
Efficient Synthesis ◽  
Target Molecules ◽  
Presence And Absence

Ionic Liquid assisted efficient synthesis of some 2-aminobenzenethiols has been reported using three different Ionic Liquids (ILs) namely methylimidazolium tetrafluoroborate [MIM]+[BF4]−, methylimidazolium chloride [MIM]+[Cl]− and methylimidazolium nitrate [MIM]+[NO3]−. A comparative study has been carried out for the synthesis of target molecules in the presence and absence of IL, leading to conclusion that maximum yield has been observed with [MIM]+[BF4]−.

Dispersive Liquid-Liquid Microextraction Based on Ionic Liquid and Spectrophotometric Determination of Bilirubin in Biological Samples

2020 ◽  
Vol 16 (5) ◽  
pp. 652-659
Author(s):  
Asiye A. Avan ◽  
Hayati Filik
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Biological Samples ◽  
Urine Samples ◽  
Spectrophotometric Detection ◽  
Full Color ◽  
Dispersive Liquid Liquid Microextraction ◽  
Urine And Serum ◽  
Liquid Microextraction

Background: An Ionic Liquid-based based Dispersive Liquid-Liquid Microextraction (IL-DLLME) method was not applied to preconcentration and determination of bilirubin. Ionic Liquids (ILs) are new chemical compounds. In recent years, Ionic Liquids (ILs) have been employed as alternative solvents to toxic organic solvents. Due to these perfect properties, ILs have already been applied in many analytical extraction processes, presenting high extraction yield and selectivity for analytes. Methods: In this study, IL-DLLME was applied to biological samples (urine and serum) for the spectrophotometric detection of bilirubin. For bilirubin analysis, the full-color development was based on the reaction with periodate in the presence of hydrochloric acid. The high affinity of bilirubin for the ionic liquid phase gave extraction percentages above 98% in 0.3 M HCl solution. Results: Several IL-extraction parameters were optimized and room temperature ionic liquid 1-butyl- 1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide and ethanol were used as extraction and disperser solution. The linear range was found in the range of 0.5-6.0 μM (0.3-3.5 μg mL-1) and the limits of detection of the proposed method was 0.5 μM (0.3 μg mL-1). The proposed method was applied for the preconcentration and separation of trace bilirubin in real urine samples. Also, the recoveries for bilirubin in spiked biological samples (urine and serum) were found to be acceptable, between 95-102%. Conclusion: The proposed IL-DLLMEapproach was employed for the enrichment and determination of trace levels of bilirubin in urine samples using NaIO4 as an oxidizing agent and Uv-vis spectrophotometric detection. The periodate oxidation of bilirubin is rapid, effective, selective, and simple to perform. The method contains only HCl, NaOI4, and an anionic surfactant. The method may be useful for economizing in the consumption of reagents in bilirubin determining. The IL-DLLMEmethod ensures a high yield and has a low toxicity no skin sensitization, no mutagenicity and no ecotoxicity in an aquatic environment since only very low quantities of an IL is required. For full-color formation, no any extra auxiliary reagents are required. Besides, the IL-DLLME technique uses a low-cost instrument such as Uv-vis which is present in most of the medical laboratories.

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