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Abstract
We report the application of surface-active ionic liquids as ligands and optional reaction media in iridium-catalyzed water oxidations. Three novel catalysts with N,N-dialkylimidazolidin-2-ylidene ligands based on amphiphilic imidazolium ionic liquids were synthesized and characterized. Excellent turn-over frequencies of up to 0.92s−1 were obtained in catalytic water splitting, and activity was maintained for five consecutive catalytic cycles, with an overall turn-over number of 8967. The addition of external surface-active ionic liquid showed unexpected behaviour, because strongly enhanced initial reaction rates were observed.
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Selective Hydrogenation of Aldehydes Using a Well-Defined Fe(II) PNP Pincer Complex in Biphasic Medium. ChemCatChem 2018; 10:4386-4394. [PMID: 30450132 PMCID: PMC6221069 DOI: 10.1002/cctc.201800841] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Indexed: 11/09/2022]
Abstract
A biphasic process for the hydrogenation of aldehydes was developed using a well-defined iron (II) PNP pincer complex as model system to investigate the performance of various ionic liquids. A number of suitable hydrophobic ionic liquids based on the N(Tf)2 - anion were identified, allowing to immobilize the iron (II) catalyst in the ionic liquid layer and to facilitate the separation of the desired alcohols. Further studies showed that targeted Brønsted basic ionic liquids can eliminate the need of an external base to activate the catalyst.
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Valorization of olive tree leaves: Extraction of oleanolic acid using aqueous solutions of surface-active ionic liquids. Sep Purif Technol 2018; 204:30-37. [PMID: 30319309 PMCID: PMC6179138 DOI: 10.1016/j.seppur.2018.04.042] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The global olive oil industry annually generates approximately 750,000-1,500,000 tons of Olea europaea leaves as waste that are typically burned for energy production. Yet, this agricultural by-product is a rich source of oleanolic acid, a high value triterpenic acid with outstanding pharmaceutical and nutraceutical activities. The present study focuses on the extraction of oleanolic acid from dried O. europaea leaves using aqueous solutions of surface-active ionic liquids as alternative solvents. A number of imidazolium-based ionic liquids with variable chain length, different anions and optional side-chain functionalization was synthesized and employed in the extraction of oleanolic acid. Ionic liquids with long alkyl chains remarkably enhance the solubility of oleanolic acid in water, thus being able to compete with the solubilities afforded by molecular organic solvents, such as chloroform. Consequently, they are suitable alternatives for the solid-liquid extraction of triterpenic acids from natural matrices and provide improved extraction yields of up to 2.5 wt% oleanolic acid extracted from olive tree leaves.
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Chemoselective Supported Ionic-Liquid-Phase (SILP) Aldehyde Hydrogenation Catalyzed by an Fe(II) PNP Pincer Complex. ACS Catal 2018. [DOI: 10.1021/acscatal.7b04149] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Carbon-based SILP catalysis for the selective hydrogenation of aldehydes using a well-defined Fe(ii) PNP complex. Catal Sci Technol 2018. [DOI: 10.1039/c8cy00818c] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this work, the supported ionic liquid phase (SILP) method was applied for the immobilization of a newly developed, well-defined hydride Fe(ii) PNP pincer complex dissolved an in ionic liquid (IL) onto polymer-based spherical activated carbon.
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Thermodynamic study for micellization of imidazolium based surface active ionic liquids in water: Effect of alkyl chain length and anions. Colloids Surf A Physicochem Eng Asp 2017. [DOI: 10.1016/j.colsurfa.2017.01.062] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Hydration and Counterion Binding of [C 12MIM] Micelles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:9844-9856. [PMID: 28786678 DOI: 10.1021/acs.langmuir.7b02201] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Surface-active ionic liquids based on imidazolium cations are promising targets for micellar catalysis in aqueous solution, yielding enhanced rate constants compared to surfactants based on n-alkyltrimethylammonium cations and exhibiting a pronounced counterion dependence ( Bica Chem. Commun. 2012 , 48 , 5013 - 5015 ; Cognigni Phys. Chem. Chem. Phys. 2016 , 18 , 13375 - 13384 ). Probably most relevant to these effects is the interplay between headgroup hydration and counterion binding. To obtain more detailed information on these effects, aqueous solutions of 1-dodecyl-3-methylimidazolium ([C12MIM]) bromide, iodide, and triflate (TfO-) were investigated at 45 °C using broadband dielectric spectroscopy, viscosity measurements, and small-angle X-ray scattering experiments. Effective hydration numbers were determined, and information on the locations and mobilities of the condensed counterions, X-, was derived. It was found that [C12MIM] halide micelles were less hydrated than the corresponding n-dodecyltrimethylammonium ([C12TA]X) aggregates. Together with their somewhat weaker counterion condensation, this difference probably explains their higher catalytic activity. Whereas [C12MIM]Br micelles remained roughly spherical in the studied concentration range, rodlike aggregates were formed at high concentrations of the iodide and, in particular, the triflate surfactants. It appears that the much lower mobility of condensed TfO- counterions is the reason for the very low catalytic activity of [C12MIM]TfO micelles.
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Acyclovir as an Ionic Liquid Cation or Anion Can Improve Aqueous Solubility. ACS OMEGA 2017; 2:3483-3493. [PMID: 31457670 PMCID: PMC6640931 DOI: 10.1021/acsomega.7b00554] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 06/28/2017] [Indexed: 06/10/2023]
Abstract
Six ionic liquid (IL)-forming ions (choline, tetrabutylphosphonium, tetrabutylammonium, and trimethylhexadecylammonium cations, and chloride and docusate anions) were paired with acyclovir as the counterion to form four low melting solid salts and two waxes; five of these compounds could be classified as ILs. All of the newly synthesized acyclovir ILs exhibited increased aqueous solubilities by at least 2 orders of magnitude when compared to that of neutral acyclovir. For three of the prepared compounds, the solubilities in simulated body fluids (phosphate-buffered saline, simulated gastric, and simulated intestinal fluids) were also greatly enhanced when compared to that of neutral acyclovir. Acyclovir in its anionic form was more water- or buffer-soluble than acyclovir in its cationic form, though this might be the effect of the particular ions, indicating that the solubilities can be finely tuned by proper choice of the cationic or anionic form of acyclovir and the counterion paired with it.
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Anti-inflammatory choline based ionic liquids: Insights into their lipophilicity, solubility and toxicity parameters. J Mol Liq 2017. [DOI: 10.1016/j.molliq.2017.02.027] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Computational analysis of the solvation of coffee ingredients in aqueous ionic liquid mixtures. RSC Adv 2017; 7:3495-3504. [PMID: 28496974 PMCID: PMC5361174 DOI: 10.1039/c6ra24736a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 10/29/2016] [Indexed: 12/19/2022] Open
Abstract
In this paper, we investigate the solvation of coffee ingredients including caffeine, gallic acid as representative for phenolic compounds and quercetin as representative for flavonoids in aqueous mixtures of the ionic liquid 1-ethyl-3-methylimidazolium acetate [C2mim][OAc] at various concentrations. Due to the anisotropy of the solutes we show that classical Kirkwood-Buff theory is not appropriate to study solvation effects with increasing ionic liquid content. However, excess coordination numbers as well as the mean residence time of solvent molecules at the surface of the solutes can be determined by Voronoi tessellation. Since the volume of the hydration shells is also available by this method, solvation free energies will be discussed as a function of the ionic liquid concentration to yield a physical meaningful picture of solvation for the anisotropic solutes. Hydrogen bonding capabilities of the solutes and their relevance for experimental extraction yields from spent coffee grounds are also discussed.
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Surface-active ionic liquids for palladium-catalysed cross coupling in water: effect of ionic liquid concentration on the catalytically active species. RSC Adv 2017; 7:41144-41151. [PMID: 29308189 PMCID: PMC5708357 DOI: 10.1039/c7ra07757b] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 08/10/2017] [Indexed: 01/02/2023] Open
Abstract
We report the design and synthesis of surface-active ionic liquids for application in palladium-catalyzed cross coupling reactions.
We report the design and synthesis of surface-active ionic liquids for application in palladium-catalyzed cross coupling reactions. A series of dodecylimidazolium-based ionic liquids were applied as additives in the Heck reaction of ethyl acrylate and iodobenzene, and high yields of >90% could be obtained in water without the addition of further ligands. Our results indicate that the ionic liquid concentration in water is the key factor affecting the formation of the catalytically active species and hence the yield. Moreover, imidazolium-based ionic liquids that are able to form a carbene species differ significantly from conventional cationic surfactants, as a concentration dependent formation of the N-heterocyclic carbene complex was observed.
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Surface-active ionic liquids in catalysis: Impact of structure and concentration on the aerobic oxidation of octanol in water. J Colloid Interface Sci 2016; 492:136-145. [PMID: 28081457 DOI: 10.1016/j.jcis.2016.12.063] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Revised: 12/23/2016] [Accepted: 12/26/2016] [Indexed: 11/19/2022]
Abstract
We present design and synthesis of surface-active ionic liquids for the application in micellar catalysis. A series of 1-methyl-3-dodecylimidazolium based ionic liquids with variable core structures including dicationic and zwitterionic ones was synthesized and characterized. These surface-active ionic liquids where applied in the aerobic oxidation of aliphatic alcohols to carbonyl compounds. A strong dependence on the ionic liquid concentration and structure was identified, which is in accordance with the concepts of micellar catalysis. Optimum conditions for the oxidation of 1-octanol could be identified, and the use of surface-active ionic liquids strongly improved the reaction performance compared to pure water. Under optimized conditions, it was possible to isolate up to 75% of octanoic acid using only small amounts of surface-active ionic liquid in a 0.05mM solution in water without further ligands.
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Fluorine-free, liquid-repellent surfaces made from ionic liquid-infused nanostructured silicon. MONATSHEFTE FUR CHEMIE 2016; 148:167-177. [PMID: 28127102 PMCID: PMC5225213 DOI: 10.1007/s00706-016-1888-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 11/29/2016] [Indexed: 11/30/2022]
Abstract
ABSTRACT Liquid-repellent surfaces based on slippery liquid-infused porous substrates (SLIPS) were prepared from porous, nanostructured silicon surfaces with different surface functionalization, infused with the polar ionic liquid 1-ethyl-3-methylimidazolium methylsulfate ([C2mim]MeSO4). Contrary to nonpolar SLIPS based on perfluorinated substrates and infusion liquids, [C2mim]MeSO4 forms stable SLIPS with high energy surfaces like native silicon (Si-SiO2) or ionic liquid-functionalized silicon (Si-[C3mim]Cl), whose liquid-repellent properties against low surface tension liquids (toluene, cyclohexane) were demonstrated by very low sliding angles (α < 3°) and low contact angle hysteresis (Δθ < 10°). These polar, ionic liquid-based SLIPS present a promising, environmentally benign extension of liquid-infused substrates to natural, high-energy oxide surfaces. GRAPHICAL ABSTRACT
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Abstract
The design and properties of surface-active ionic liquids that are able to form stable microemulsions with heptane and water are presented, and their promise as reaction media for thermomorphic palladium-catalyzed cross-coupling reactions is demonstrated.
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Surface-active ionic liquids in micellar catalysis: impact of anion selection on reaction rates in nucleophilic substitutions. Phys Chem Chem Phys 2016; 18:13375-84. [PMID: 27121134 PMCID: PMC5317217 DOI: 10.1039/c6cp00493h] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A series of surface-active ionic liquids based on the 1-dodecyl-3-methylimidazolium cation and different anions was synthesized and applied for micellar catalysis of nucleophilic substitutions.
A series of surface-active ionic liquids based on the 1-dodecyl-3-methylimidazolium cation and different anions such as halides and alkylsulfates was synthesized. The aggregation behavior of these ionic liquids in water was characterized by surface tension, conductivity measurements and UV-Vis spectroscopy in order to determine the critical micelle concentration (CMC) and to provide aggregation parameters. The determination of surface activity and aggregation properties of amphiphilic ionic liquids was accompanied by SAXS studies on selected surface-active ionic liquids. The application of these surface-active ionic liquids with different anions was tested in nucleophilic substitution reactions for the degradation of organophosphorus compounds. Kinetic studies via UV-Vis spectrophotometry showed a strong acceleration of the reaction in the micellar system compared to pure water. In addition, an influence of the anion was observed, resulting in a correlation between the anion binding to the micelle and the reaction rate constants, indicating that the careful choice of the surface-active ionic liquid can considerably affect the outcome of reactions.
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Abstract
Residual chloride in ionic liquids is analyzed using LA-ICP-MS in a sustainable and easy-to-handle approach.
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Amino alcohol-derived chiral ionic liquids: structural investigations toward chiral recognition. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.tetasy.2015.08.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Coordinating Chiral Ionic Liquids: Design, Synthesis, and Application in Asymmetric Transfer Hydrogenation under Aqueous Conditions. European J Org Chem 2015; 2015:2374-2381. [PMID: 26279638 PMCID: PMC4529664 DOI: 10.1002/ejoc.201403555] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Indexed: 11/26/2022]
Abstract
Hydrophilic coordinating chiral ionic liquids with an amino alcohol substructure were developed and efficiently applied to the asymmetric reduction of ketones. Their careful design and adaptability to the desired reaction conditions allow for these chiral ionic liquids to be used as the sole source of chirality in a ruthenium-catalyzed transfer hydrogenation reaction of aromatic ketones. When used in this reaction system, these chiral ionic liquids afforded excellent yields and high enantioselectivities.
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Fast and efficient extraction of DNA from meat and meat derived products using aqueous ionic liquid buffer systems. NEW J CHEM 2015. [DOI: 10.1039/c5nj00178a] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We present a fast and efficient strategy for DNA extraction from meat based on aqueous-ionic liquid systems that could extract DNA in significantly higher yields compared to the pure phosphate buffer.
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Abstract
We present the application of ionic liquid-aqueous micellar solutions as isolation media for the pharmaceutically active ingredient piperine from black pepper. Several surface-active ionic liquids including a biodegradable betaine derivative were used for the extraction of piperine, and a strong correlation between extraction yield and the critical micelle concentration of the respective ionic liquid was found. A scaled strategy for the isolation of piperine was developed that allowed recovery and recycling of the aqueous ionic liquid micellar solution for five runs without any loss in extraction efficiency.
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Automated evaluation of pharmaceutically active ionic liquids' (eco)toxicity through the inhibition of human carboxylesterase and Vibrio fischeri. JOURNAL OF HAZARDOUS MATERIALS 2014; 265:133-141. [PMID: 24355776 DOI: 10.1016/j.jhazmat.2013.11.052] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 11/04/2013] [Accepted: 11/24/2013] [Indexed: 06/03/2023]
Abstract
The toxicity of 16 pharmaceutical active ionic liquids (IL-APIs) was evaluated by automated approaches based on sequential injection analysis (SIA). The implemented bioassays were centered on the inhibition of human carboxylesterase 2 and Vibrio fischeri, in the presence of the tested compounds. The inhibitory effects were quantified by calculating the inhibitor concentration required to cause 50% of inhibition (EC50). The EC50 values demonstrated that the cetylpyridinium group was one of the most toxic cations and that the imidazolium group was the less toxic. The obtained results provide important information about the safety of the studied IL-APIs and their possible use as pharmaceutical drugs. The developed automated SIA methodologies are robust screening bioassays, and can be used as a generic tools to identify the (eco)toxicity of the structural elements of ILs, contributing to a sustainable development of drugs.
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Design, synthesis, and application of novel chiral ONN ligands for asymmetric alkylation. MONATSHEFTE FUR CHEMIE 2013. [DOI: 10.1007/s00706-012-0900-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Active pharmaceutical ingredients based on salicylate ionic liquids: insights into the evaluation of pharmaceutical profiles. NEW J CHEM 2013. [DOI: 10.1039/c3nj00731f] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Prodrug ionic liquids: functionalizing neutral active pharmaceutical ingredients to take advantage of the ionic liquid form. MEDCHEMCOMM 2013. [DOI: 10.1039/c3md20359j] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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30
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Exploring ionic liquid–biomass interactions: towards the improved isolation of shikimic acid from star anise pods. RSC Adv 2013. [DOI: 10.1039/c3ra45572f] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
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31
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Iron catalyzed Michael addition: Chloroferrate ionic liquids as efficient catalysts under microwave conditions. Sci China Chem 2012. [DOI: 10.1007/s11426-012-4657-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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32
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Pharmaceutically active ionic liquids with solids handling, enhanced thermal stability, and fast release. Chem Commun (Camb) 2012; 48:5422-4. [DOI: 10.1039/c2cc30959a] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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From Solvent to Sustainable Catalysis - Chloroferrate Ionic Liquids in Synthesis. Curr Org Synth 2011. [DOI: 10.2174/157017911804586548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Liquid forms of pharmaceutical co-crystals: exploring the boundaries of salt formation. Chem Commun (Camb) 2011; 47:2267-9. [DOI: 10.1039/c0cc04485g] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Crystalline vs. ionic liquid salt forms of active pharmaceutical ingredients: a position paper. Pharm Res 2010; 27:521-6. [PMID: 20143257 DOI: 10.1007/s11095-009-0030-0] [Citation(s) in RCA: 267] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Accepted: 12/04/2009] [Indexed: 12/13/2022]
Abstract
Why not consider liquid salt forms of active pharmaceutical ingredients (APIs) as an alternative versatile tool in the pharmaceutical industry? Recent developments have shown that known APIs can be readily converted into ionic liquids and that these novel phases often possess different properties (e.g., improved solubilities and dissolution rates), which may have a direct impact on the pharmacokinetics and pharmacodynamics of the drug. They may also offer the potential of novel and more efficient delivery modes, as well as patent protection for each of the new forms of the drug. Since these pharmaceutically active ionic liquids represent a thermodynamically stable phase, they avoid the troublesome issues surrounding polymorphism and "polymorphic transformation." In some cases, an active cation and an active anion can be combined to produce a liquid possessing dual functionality. Here we examine and challenge the current industry reliance on crystalline APIs by discussing the breadth and potential impact of liquid salts as a possible approach to phase control.
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In search of pure liquid salt forms of aspirin: ionic liquid approaches with acetylsalicylic acid and salicylic acid. Phys Chem Chem Phys 2010; 12:2011-7. [PMID: 20145871 DOI: 10.1039/b923855g] [Citation(s) in RCA: 142] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We present an ionic liquid (IL) approach towards a dual functional liquid salt form of aspirin using different pharmaceutically active cations composed of antibacterials, analgesics, local anesthetics, and antiarrhythmic drugs in combination with acetylsalicylic acid or its metabolite salicylic acid and discuss stability of these ILs in comparison to solid salts. Several low-melting or liquid salts of salicylic acid with dual functionality and promising properties were isolated and characterized; however, although such ILs with aspirin could be prepared, they suffer from limited stability and slowly decompose into the corresponding salicylate ILs when exposed to moisture.
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Confused ionic liquid ions--a "liquification" and dosage strategy for pharmaceutically active salts. Chem Commun (Camb) 2010; 46:1215-7. [PMID: 20449254 DOI: 10.1039/b925147b] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We present a strategy to expand the liquid and compositional ranges of ionic liquids, specifically pharmaceutically active ionic liquids, by simple mixing with a solid acid or base to form oligomeric ions.
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Metal-Containing Ionic Liquids as Efficient Catalysts for Hydroxymethylation in Water. European J Org Chem 2008. [DOI: 10.1002/ejoc.200800323] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Microwave-Assisted Synthesis of Camphor-Derived Chiral Imidazolium Ionic Liquids and Their Application in Diastereoselective Diels-Alder Reaction. SYNTHESIS-STUTTGART 2007. [DOI: 10.1055/s-2007-966018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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43
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Synthesis and analytics of 2,2,3,4,4-d5-19-nor-5alpha-androsterone--an internal standard in doping analysis. Steroids 2007; 72:429-36. [PMID: 17383698 DOI: 10.1016/j.steroids.2007.01.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2006] [Revised: 01/24/2007] [Accepted: 01/31/2007] [Indexed: 11/20/2022]
Abstract
A short and efficient synthesis of pentadeuterated 2,2,3,4,4-d5-19-nor-5alpha-androsterone 7 starting from 19-norandrost-4-ene-3,17-dione 1 by a d1-L-Selectride mediated stereo- and regioselective reduction of the 3-keto group is presented. The use of compound 7 as internal standard for the detection of anabolic steroids via mass spectrometric techniques such as gas chromatography-mass spectrometry (GC-MS) is discussed.
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An Iron-Containing Ionic Liquid as Recyclable Catalyst for Aryl Grignard Cross-Coupling of Alkyl Halides. Org Lett 2006; 8:733-5. [PMID: 16468754 DOI: 10.1021/ol052965z] [Citation(s) in RCA: 164] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
[reaction: see text] The ionic liquid butylmethylimidazolium tetrachloroferrate (bmim-FeCl(4)) was found to be a very effective and completely air stable catalyst for the biphasic Grignard cross-coupling with primary and secondary alkyl halides bearing beta-hydrogens. After simply decanting the product in the ethereal layer, the ionic liquid catalyst was successfully recycled four times.
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