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Eutectic solvents are tunable for targeted applications through the functional groups in their hydrogen bond acceptor (HBA) and hydrogen bond donor (HBD) components, as well as the HBA : HBD composition ratio. This study examines the properties of choline-based eutectics containing imidazole, phenol, pyrrole-2-carbonitrile, and 1,2,4-triazole HBAs, and ethylene glycol, 1,2-propylene glycol, and ethanolamine HBDs. The viscosity, conductivity, degree of hydrogen bonding, thermal stability, and solvatochromic properties are examined as a function of HBA, HBD, and the composition. These studies revealed a predominant dependence of physical properties on the HBD and determined that the strong hydrogen bonding in phenol and imidazole-based systems lead to higher viscosities and lower conductivities – critical parameters for CO2 capture and electrochemical conversion. The developed eutectic solvents were further evaluated in terms of their CO2 capture capacities and electrochemical stabilities. Solvatochromic properties were found to correlate with CO2 capacities, demonstrating the tunability of these solvents for CO2 capture. The quantitative structure–property relationship (QSPR) analysis demonstrated the ability to predict viscosities and CO2 capture capacities (<25% deviation) through a multi linear regression method utilizing five molecular descriptors. This work highlights the role of functionalized HBAs and HBDs in the physical, thermal, and electrochemical properties of eutectic solvents as they relate to CO2 capture and electrochemical processes. [ABSTRACT FROM AUTHOR]

The development of convenient and practical synthetic strategies for constructing bioactive molecules without metal residues is of great interest in organic synthesis. Herein, a metal-free, operationally simple, and scalable electrooxidation-induced three-component cross-coupling method to access 3-thio/selenophosphorylated imidazole derivatives from readily available isothiocyanates/isoselenocyanates, isocyanates, and H-phosphonates is first reported. More than 30 examples have been provided with good to moderate yields. Importantly, the readily accessible compounds could be used as pesticides (wheat anti-locust) with good biocompatibility (5d-stimulated RAW 264.7 macrophages, IL-6 = 5.3 pg mL−1, THF-α = 79.8 pg mL−1), reiterating the importance of the developed electrochemical methodology. [ABSTRACT FROM AUTHOR]

The simultaneous achievement of large surface areas and high IL contents in porous materials are highly beneficial for efficient carbon dioxide (CO2) capture and atmospheric fixation. Herein, a series of porous hypercrosslinked poly(ionic liquid)s (HPILs) are successfully developed through a two-step synthetic strategy, including free radical self-polymerization of a specific benzyl bromide-tethered imidazole ionic liquid (IL) to fabricate a linear PIL as a precursor, and a subsequent Friedel–Crafts alkylation between the precursor and the crosslinker for hypercrosslinking. The HPILs featured large surface areas of up to 855 m2 g−1 along with a hierarchically nanoporous structure, high IL contents (2.19–2.91 mmol g−1) and satisfactory CO2-philic properties. By virtue of the combined advantages, HPILs served as metal-free heterogeneous catalysts for solvent-additive-free CO2 cycloaddition with epichlorohydrin at 80 °C and 0.1 MPa CO2 for 24 h, presenting high catalytic activity and stable reusability. A high yield of 99.0% coupled with a turnover frequency (TOF) of 6.0 h−1 was achieved, much higher than most of the reported metal-free heterogeneous catalysts, even superior to homogeneous analogues. Furthermore, various epoxides, including large-sized epoxides, were effectively converted into carbonates with high yields, affording good substrate applicability. This work reports a facile and universal approach for the construction of porous HPILs with both great porosities and high IL contents towards efficient chemical fixation of CO2 under mild conditions. [ABSTRACT FROM AUTHOR]

Many studies have been focused on the selective separation of hydrogen chloride (HCl) gas, but its capture and conversion in situ is still at a standstill. Herein, a pioneering attempt to employ a deep eutectic solvent (DES) as a "courier" to combine HCl capture and in situ conversion has been presented. Impressively, the highest HCl absorption capacity is determined to be 3.95 mol/mol, or 0.672 g/g, or 18.4 mol kg-1 at 1.0 bar and 30 °C in a binary DES based on EmimCl/Im. The internal transmission mechanism between imidazole and HCl was revealed by DFT-based theoretical calculations. The reaction between HCl and epoxides achieved 99% conversion under mild conditions in the absence of a solvent, making the entire reaction ecologically benign. Water extraction was used to recycle the DES from the reaction system, and it maintained good catalytic performance after ten cycles. The exhaust HCl-SO2 mixed gases from the sucralose industry were further investigated, which proved the possibility of selective conversion of HCl. Furthermore, a plausible reaction-separation-integration (RSI) strategy was proposed to avoid the high energy consumption of desorption, which provides a novel insight into future applications. It is believed that the good results, combined with the simplicity of operation and the high recyclability of the catalyst, make this green method environmentally friendly and cost-effective. This work reveals an effective approach for the coupling of HCl capture and conversion under mild conditions. [ABSTRACT FROM AUTHOR]

An expeditious one-pot method for the synthesis of highly substituted 5-aminoimidazoles from glyoxals, anilines, and amidines was evaluated under metal/catalyst-free conditions operative at room temperature. The present protocol constitutes an environmentally friendly approach for the synthesis of highly substituted 5-aminoimidazoles, which are important building blocks of several bioactive and medicinal compounds. The readily and commercially available starting materials can be quickly assembled into imidazoles using this protocol and scaling up this process does not require chromatographic purification. Additionally, the reaction of 5-aminoimidazole with 2-bromobenzoyl chloride can provide a novel imidazo[5,1-b]quinazolin-9(4H)-one, thus showcasing the applicability of this protocol. [ABSTRACT FROM AUTHOR]

An original approach to achieve the C(sp2)–H azolation of cyclic aldonitrones mediated by Selectfluor® has first been employed. By exploiting a metal-free, visible-light-promoted cross-dehydrogenative C–N coupling reaction between model aldonitrones, 2H-imidazole 1-oxides, and NH-containing azoles, a series of novel azaheterocyclic derivatives have been obtained in yields up to 94%. The elaborated protocol has proved to be appropriate for gram-scale processes and displayed potential for utilization in the synthesis of novel structural analogues of lanabecestat. Besides, mechanistic studies have revealed that this coupling reaction is likely to proceed via a nitroxide-involving radical pathway, encompassing a chain of electron transfer events, such as hydrogen atom transfer (HAT) and single electron transfer (SET). [ABSTRACT FROM AUTHOR]

Alcoholysis is a potential method for the degradation of polyesters to their precursor building blocks, which can then be polymerized again to form new qualified polyester materials. This method therefore makes recycling possible in a permanent polymer–monomer–polymer loop. In this study, a series of metal-free tetrabutylphosphonium-based ionic liquids (ILs) were prepared as catalysts for the methanolysis of poly(ethylene 2,5-furandicarboxylate) (PEF), which is well known as an ideal alternative to the petroleum-based plastic poly(ethylene terephthalate) (PET). It was found that anions with stronger electronegativity were more efficient for the methanolysis of PEF. By adjusting the structures of the anions and cations of ILs, 1-butyl-3-methylimidazole acetate ([BMIm][OAc]) exhibited excellent catalytic activity in the methanolysis of PEF. The optimization of reaction parameters enabled the [BMIm][OAc]-catalyzed methanolysis of PEF with nearly 100% PEF degradation and a 77.6% dimethyl furan-2,5-dicarboxylate (DMFD) yield at 130 °C for 30 min. Furthermore, [BMIm][OAc] could keep high-activity after using for six times under the optimum conditions. Assisting with 1H NMR, FT-IR and density functional theory (DFT) calculations, an in-depth study was performed on the feasible synergetic catalytic mechanism of [BMIm][OAc] for the methanolysis of PEF, induced by hydrogen bonds formed between reactants and [BMIm][OAc]. Finally, on the basis of experimental results and scanning electron microscopy (SEM), it was confirmed that PEF with the spiral motif could be degraded under milder conditions than PET. Therefore, this strategy of using adjustable cation and anion structures in ILs provides an opportunity to develop other more efficient ILs for the alcoholysis of furan-based polymers via a green and mild pathway. [ABSTRACT FROM AUTHOR]

In this study, a series of high-activity imidazole-based dicationic ionic liquids (DILs) were designed and prepared as efficient catalysts for balancing the reactivity between the endo-hydroxyl group (endo-OH) and the exo-hydroxyl group (exo-OH) of isosorbide (ISO) to synthesize high molecular weight poly(isosorbide carbonate) (PIC). Meanwhile, the thermal performance of PIC was precisely optimized by regulating the chain configuration. The results showed that when the trace amounts (4.5 × 10−5 based on the ISO molar amount) of bis-(3-methyl-1-imidazole)-ethylene dibromide ([C2(Min)2][Br]2) were used, the weight average molecular weight (Mw) of PIC reached 98 700 g mol−1. It could be concluded from the results of the experiment and the stimulation that the high catalytic activity of DILs was attributed to the strong electrostatic interaction between the cation and the substrate and the effective balance of the reactivity of the endo-OH and the exo-OH. Furthermore, we found that the reduction of hydroxyl groups in the terminal groups and the increase of endo–endo (a1) structure in the repeating unit improved the thermal properties of PIC. Finally, 1H NMR, Fourier infrared spectroscopy, and density functional theory (DFT) calculations were used to verify the reaction process through anion and cation multi-site synergistic effect and a possible electrophilic–nucleophilic reaction mechanism was successfully obtained. [ABSTRACT FROM AUTHOR]

The separation of aromatics from aliphatics is challenging and energy-consuming because of the very close boiling points among these compounds and the possibility of forming azeotropes. In this work, we designed two imidazolium-based dicationic ionic liquids, [C5(MIM)2][NTf2]2 (DIL1) and [C6(MIM)2][NTf2]2 (DIL2), and found that they could highly efficiently extract aromatics from aliphatics. Three different aromatic and aliphatic mixtures, toluene/n-heptane, benzene/n-hexane and benzene/cyclohexane, were used to investigate the universality of DILs. The extractive performance of both DILs was compared with those of other promising ILs and sulfolane. The mixtures of toluene and aliphatics with different chain lengths were also investigated. The results showed that the two DILs had relatively high selectivity and distribution coefficients for different aromatic and aliphatic mixtures. At 30 °C, the highest values of selectivity and distribution coefficient for toluene/n-heptane, benzene/n-hexane and benzene/cyclohexane systems were 50.4, 64.8, and 24.9 and 1.44, 2.44, and 2.25, respectively. The performance of DILs at 30 °C was better than that at 40 °C. Besides, a higher selectivity could be obtained when toluene is used with a longer chain aliphatic, such as a selectivity of 61.4 could be obtained when the aliphatic was n-nonane. The study of the physicochemical properties of DILs showed that they were more stable than the previous ones. In a word, the two DILs were evaluated as potential solvents for the separation of aromatics from aliphatics. [ABSTRACT FROM AUTHOR]

Hierarchical porous zeolitic imidazolate framework ZIF-8 nanoparticles have been synthesized using zinc nitrate, 2-methylimidazole (Hmim), and sodium hydroxide. Zinc hydroxide nitrate nanosheets were formed as intermediates that further transformed to hierarchical porous ZIF-8 after the addition of Hmim. These intermediates serve as in situ sacrificial templates and promote the formation of hierarchical porous ZIF-8 without the need for any other templates. The surface area and mesoporosity of the materials can be tuned by adjusting the concentration of NaOH. This method offers a fast and template-free approach for the synthesis of pure hierarchical porous ZIF-8 at room temperature with tunable porosity. The approach has been applied to synthesize two-dimensional ZIF leaf-like materials, ZIF-L. The synthesis of ZIF-8 and ZIF-L can be scaled up with high yields (＞80%). The resulting ZIF-8 and ZIF-L materials show very good CO2 sorption properties. ZIF-8 nanoparticles show fast (＜5 min), selective, and high efficiency (＞95%) uptake of methyl blue in aqueous solution both without and in the presence of other dyes. The results open a new avenue for the understanding of the self-assembly and the formation of hierarchical porous ZIFs. [ABSTRACT FROM AUTHOR]

An efficient and practical aerobic benzylic sp3 C–H oxidation as a key step towards the domino multi-component synthesis of 2,4,5-trisubstituted imidazoles has been reported. This green methodology employs an inexpensive catalytic copper/oxygen system and proceeds under mild reaction conditions. A variety of substituted imidazoles are prepared in moderate to excellent yields from α-methylene ketones using this innovative methodology. [ABSTRACT FROM AUTHOR]

Solid imidazolium-based polyionic liquids (PILs; a class of polyelectrolyte) were synthesized for the absorption of n-butanol and other inhibitory biosynthesis products from dilute aqueous solutions. Conventional hydrogels prepared by cross-linking water-soluble PILs demonstrated biocompatibility with Saccharomyces cerevisiae, successfully eliminating cytotoxicity concerns associated with the IL monomers. However, the cross-linked PILs’ solute absorption capacity and selectivity for butanol relative to water were below the levels likely needed for a viable extractive fermentation process. Uncross-linked PILs bearing long-chain aliphatic substituents also proved to be biocompatible by virtue of their insolubility in water, and delivered significantly improved absorptive performance. Among biocompatible absorbents, these PILs demonstrated some of the highest absorptions of n-butanol and other hydrophilic fermentation products reported to date, with n-butanol partition coefficient (PC) values up to 7.6 and butanol/water selectivity (αb/w) values up to 78. The influence of linear N-alkyl side chain length (C8 to C16) and counter anions (Cl−, Br−, I−, BF4−, co-SS−) on solute partition coefficient, selectivity and physical properties are detailed and discussed. In all, this work demonstrates that polymerization of cytotoxic ILs can successfully yield biocompatible absorbents with excellent absorptive performance for the recovery of hydrophilic bioproducts. [ABSTRACT FROM AUTHOR]

This manuscript describes the using of biosourced l-valine, oxalic acid and glyoxal to produce a biobased imidazolium hydrogen oxalate [iBu2IM](HC2O4) which is converted to its related hydrogen carbonate salt by a simple electrolysis without using strong base. The addition of weak protic acids to the latter compound leads to a rapid and quantitative CO2 release with formation of the starting hydrogen oxalate salt or a new halide free bio-based ionic liquid [iBu2IM](AcO) which is able to adsorb reversibly the CO2 at room temperature. The protonation reactions, combined with electrolysis, could then be a promising alternative solution for storage and transport of CO2. They are indeed fast and use a thermally and air stable material produced from sustainable resources which are easily recycled by a low energy consuming process using non-expensive and corrosion-resistant equipment. [ABSTRACT FROM AUTHOR]

Fluoroquinolones (FQs) and Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) are two classes of Active Pharmaceutical Ingredients (APIs) in widespread use in human healthcare and as veterinary drugs, and that have been found throughout the water cycle in the past years. These two classes of APIs are commonly present in aqueous streams in concentrations ranging from ng L−1 to μg L−1. Despite such low concentrations, these contaminants tend to bioaccumulate, leading to serious environmental and health issues after chronic exposure. The low concentrations of FQs and NSAIDs in aqueous media also render difficult identification and quantification, which may result in an inefficient evaluation of their environmental impact and persistence. Therefore, the development of alternative pre-treatment techniques for their extraction and preconcentration from aqueous samples is a crucial requirement. In this work, liquid–liquid systems, namely ionic-liquid-based aqueous biphasic systems (IL-based ABS), were tested as simultaneous extraction and preconcentration platforms for FQs and NSAIDs. ABS composed of imidazolium-, ammonium- and phosphonium-based ILs and a citrate-based salt (C6H5K3O7) were evaluated for the single-step extraction and enrichment of three FQs (ciprofloxacin, enrofloxacin and norfloxacin) and three NSAIDs (diclofenac, naproxen and ketoprofen) from aqueous samples. Outstanding one-step extraction efficiencies of APIs close to 100% were obtained. Furthermore, the preconcentration factors of both FQs and NSAIDs were optimized by an appropriate manipulation of the phase-forming components compositions to tailor the volumes of the coexisting phases. Preconcentration factors of 1000-fold of both FQS and NSAIDs were obtained in a single-step process, without reaching the saturation of the IL-rich phase. The preconcentration of APIs up to mg L−1 allowed their easy and straightforward identification and quantification by a High-Performance Liquid Chromatography (HPLC) system coupled to an UV detector, as shown for both model systems (distilled water) and real effluent samples from a wastewater treatment plant. [ABSTRACT FROM AUTHOR]

Copper catalysts with an imidazole salt tag ([Cu-Imace-R-H][X], X− = F−, Cl−, Br−, I−, CF3CO2−, HSO4−, NO3−, PF6− or BF4−; R = H or CH3) show quite high reactivity for the oxidation of non-aromatic olefins with good selectivity for epoxides. The reactions perform well with a part per million (ppm) catalyst loading at mild temperature and ambient pressure. The highest turnover frequency (TOF) reaches up to 900 000 h−1. The catalytic activity is easy to control by changing the anion of [Cu-Imace-R-H][X]. This catalyst is effective for a series of substrates, including internal and terminal olefins, tri- and tetra-substituted olefins and aromatic olefins. In addition, the copper catalyst can be conveniently separated from the reaction system and reused for at least six cycles without any obvious loss of catalytic activity. [ABSTRACT FROM AUTHOR]

Imidazolium ionomer derivatives of an isobutylene-rich elastomer demonstrated superior absorption characteristics for target molecules of biological interest compared to their non-ionic parent material, while retaining biocompatibility with a range of suspended cell cultures. Halide displacement from brominated poly(isobutylene-co-paramethyl styrene) was used to introduce 0.23 mmol per g-polymer of imidazolium bromide functionality to the polymer, resulting in up to 10-fold improvements in n-octanol and n-butanol partition coefficients (PCs) and up to 4-fold improvements in selectivity (α). In contrast to analogous imidazolium ionic liquids (ILs) that were cytotoxic toward Saccharomyces cerevisiae, Clostridium acetobutylicum and Pseudomonas putida, the ionomers had no effect on suspended cell growth. In addition, these ionomers demonstrated surface antimicrobial activity towards select microorganisms under static conditions with direct surface/microbe contact. Thus, these materials do not affect suspended cell growth while simultaneously reducing cell proliferation at the ionomer interface. [ABSTRACT FROM AUTHOR]

An energy efficient and economically viable bimetallic heterogeneous catalyst system composed of Co and Zn as active centers and 2-methylimidazole as a linker has been synthesized in water at room temperature. The synthesized material (CZ-ZIF) possesses a sodalite topology, similar to the parent materials, ZIF-8 and ZIF-67, with a high surface area of ＞1400 m2 g−1. The Zn and Co metal ions were shown to occupy equivalent sites throughout the framework in similar proportions, as confirmed by inductively coupled plasma atomic emission spectroscopy and energy dispersive X-ray spectroscopy techniques. CZ-ZIF rendered a high catalytic conversion of epoxides to five-membered cyclic carbonates using CO2 as the C1 source under solvent- and co-catalyst-free conditions with excellent selectivity and manifested better catalytic abilities than ZIF-67 and enhanced framework stability compared to ZIF-8. Furthermore, CZ-ZIF exhibited catalytic activity even at room temperature in the presence of a co-catalyst, and was reusable over a minimum of five cycles with no noticeable decrease in activity. A plausible mechanism for CZ-ZIF catalyzed solvent- and co-catalyst-free epoxide–CO2 cycloaddition has been proposed. [ABSTRACT FROM AUTHOR]

A facile aromatic nucleophilic substitution (SNAr) reaction in recyclable [Omim]Br under relatively mild conditions has been described. An electrophile–nucleophile dual activation by [Omim]Br is also discovered based on control experiments, 1H NMR and IR spectroscopies. This chemistry provides an efficient and metal-free approach for the generation of Caryl–X (X=S, N, O) bonds, many of which are significant synthetic intermediates or drugs, making this methodology attractive to both synthetic and medicinal chemistry. [ABSTRACT FROM AUTHOR]

The use of a hydrophobic, imidazolium-functionalized periodic mesoporous organosilica for immobilization of chiral organometallic complexes as a heterogeneous catalyst is highly desirable as this catalyst can greatly promote an aqueous organic transformation due to its hydrophobic function and phase-transfer feature in an aqueous medium. Herein, by utilizing a three-component co-condensation strategy, we conveniently incorporate 1,2-bis(triethoxysilyl)ethane, (R,R)-4-((trimethoxysilyl)ethyl)phenylsulfonyl-1,2-diphenylethylene-diamine and 1,3-bis(3-(triethoxysilyl)propyl)-1H-imidazol-3-ium iodide within its silicate network, which is coordinated with (Cp*RhCl2)2, leading to an imidazolium-modified chiral rhodium/diamine-functionalized periodic mesoporous organosilica. A solid-state carbon spectrum discloses its well-defined chiral rhodium/diamine active species, and its X-ray diffraction; nitrogen adsorption–desorption measurement and transmission electron microscopy images reveal its ordered dimensional-hexagonal mesostructure. As a bifunctional heterogeneous catalyst, this periodic mesoporous organosilica significantly boosts asymmetric transfer hydrogenation of α-haloketones and benzils in water, where the hydrophobic periodic mesoporous organosilica, phase-transfer-featured imidazolium-functionality, and the confined chiral organorhodium catalytic nature are responsible for its catalytic performance. Furthermore, the catalyst can be recovered and recycled seven times without the loss of its catalytic activity, making it an attractive heterogeneous catalyst for asymmetric transfer hydrogenation in an environmentally friendly manner. [ABSTRACT FROM AUTHOR]

A series of innovative bisimidazole-functionalized porphyrin cobalt(iii) complexes have been devised, synthesized and characterized using NMR, MS and elemental analysis. These homogeneous catalysts were applied to the cycloaddition of epoxides and carbon dioxide without organic solvent and co-catalyst. It was found that the performance of the catalysts deeply relies on their structural features. The alkoxyl chain length of the linkage and the imidazole position relative to the phenyl rings of porphyrin evidently affects the catalyst activities. [5,15-Di(3-((8-imidazolyloctyl)oxy)phenyl)porphyrin] cobalt(iii) chloride (J-m8) and [5,15-di(2-((6-imidazolylhexyl)oxy)phenyl)porphyrin] cobalt(iii) chloride (J-o6) demonstrated excellent activity under optimal reaction conditions. Synchronously, a preliminary kinetic investigation of this reaction was carried out using three catalysts and illustrated the activation energies of cyclic carbonate formation. Furthermore, a tri-synergistic catalytic mechanism has been carefully proposed in light of the features of the new catalysts and experimental results. [ABSTRACT FROM AUTHOR]

We designed highly active and practical bis(imidazole)/zinc complexes for transesterification reactions. X-ray crystallographic analysis was used to confirm the structures of the zinc complexes and an equivalent of bis(imidazole) ligand was crucial for high catalytic activity. The octahedral zinc complex 8c was prepared in up to a multigram scale by mixing Zn(OCOCF3)2·xH2O and meta-bis(imidazolylmethyl)benzene ligand 7j (two equivalents per zinc ion) and storable under air at room temperature for at least 9 months. The stable nature of the catalyst was amenable to recovery/reuse at least five times without a significant loss of reactivity. The transesterification reaction proceeded without strict reaction conditions, and expanded substrate generalities, including sterically demanding secondary and tertiary alcohols, were applicable. Remarkably, the present zinc catalyst proved highly effective for valuable monomer synthesis from readily available methyl acrylate derivatives. Chemoselective transesterification reactions of unprotected-amino alcohols were also achieved, using not only a simple methyl ester but also an unprecedented dimethyl carbonate. [ABSTRACT FROM AUTHOR]

Vitamin E (VE) has significant biological activities and thus its acylation to increase its stability is of extreme interest. We developed an efficient and sustainable approach using imidazolium-based ionic liquids as dual solvent-catalysts for the esterification between α-tocopherol (the most active form of VE) and succinic anhydride. Although in literature it is reported that lipase can catalyze this reaction, hereby we demonstrate that the reaction observed in DMSO and DMF is catalyzed by the histidyl residues of the protein. Histidine and its analogue containing an imidazole ring were tested as organocatalysts for the production of α-tocopherol succinate. In light of the imidazole organocatalysis, commercially-available 3-alkyl-1-methyl imidazolium ILs [CnC1Im][X−] were investigated as dual solvent-catalysts for the esterification of α-tocopherol with succinic anhydride, and provided satisfactory yields and reaction rates. [C5C1Im][NO3−] can be recycled by water extraction, instead of organic solvent extraction to separate α-tocopherol succinate from [C5C1Im][NO3−], with an average yield of 94.1% for 4 subsequent batches, while the catalytic activity of the recycled ILs showed almost no loss after 4 batches. The developed protocol for the synthesis of α-tocopherol esters and IL recycling bears industrial potential due to the ease of use and the efficient recycling. [ABSTRACT FROM AUTHOR]

An imidazole-based zwitterionic-salt, 4-(3-methylimidazolium)butane sulfonate (MBS), has been found to be an efficient organocatalyst for aziridine ring-opening regioselectively by various nucleophiles like indoles, pyrroles, methanol, ethanol, acetic acid and di-iso-propylamine. The reactions are highly regioselective and they always afford the products resulting from benzylic attack. The present methodology is applicable to gram scale synthesis. [ABSTRACT FROM AUTHOR]

Mo8O264− based organic polyoxomolybdate salts of general formula [Hmim]4Mo8O26 (Hmim = 1-hexyl-3-methylimidazolium), [Dhmim]4Mo8O26 (Dhmim = 1,2-dimethyl-3-hexylimidazolium) and [Hpy]4Mo8O26·H2O (Hpy = 1-hexylpyridinium) have been prepared and characterized. These compounds were applied as catalysts for olefin epoxidation using hydrogen peroxide (H2O2) as oxidant in CH3CN. The polyoxomolybdate salts exhibit excellent catalytic performance and are also self-separating, a great advantage for catalyst recycling. The catalysts can be reused for at least 10 runs without significant loss of activity. [ABSTRACT FROM AUTHOR]

A series of novel heterogeneous catalysts were developed by immobilizing imidazolium-based functionalized ionic liquids on an FDU-type mesoporous polymer. Various techniques such as X-ray diffraction, N2 adsorption-desorption, and high resolution transmission electron microscopywere used to characterize the physicochemical properties of the catalysts. Ionic liquid-functionalized mesoporous polymers serve as efficient catalysts in the solvent free cycloaddition reactions of CO2 with epoxides without the use of any co-catalyst. The catalysts can be easily recovered and reused without a significant loss of activity. In comparison with the polystyrene (PS) and mesosilica SBA-15 supports, the FDU mesopolymer possesses both the mesoporous organic framework and abundant phenolic hydroxyl groups, which are key factors in improving the catalytic performance of supported ionic liquids. [ABSTRACT FROM AUTHOR]

An air stable, water soluble, and efficient ionic liquid-tagged Schiff base palladium complex was prepared. The synthesized complex was well characterized by NMR, mass spectrometry, FT-IR, UV-visible spectroscopy and powder X-ray diffraction. The complex was used as a catalyst for the Suzuki and Heck cross-coupling reactions in water. Good to excellent yields were achieved using a modest amount of the catalyst. In addition, the catalyst can be easily reused and recycled for six steps without much loss in activity, exhibiting an example of sustainable and green methodology. [ABSTRACT FROM AUTHOR]

An electrochemical dehydrogenative [2 + 2 + 1] annulation used for the synthesis of imidazoles has been developed under undivided electrolytic conditions. In an undivided cell, aryl ketones and amines can smoothly participate in this transformation to furnish a variety of substituted imidazoles. The reaction avoids the use of both transition-metal catalysts and peroxide reagents, which makes it more sustainable and renewable. [ABSTRACT FROM AUTHOR]

A novel method to fabricate chemically linked conducting polymer–biopolymer composites that are intrinsically flexible and conducting for functional electrode applications is presented. Polypyrrole was synthesised in situ during the cellulose regeneration process using the 1-butyl-3-methylimidazolium chloride ionic liquid as a solvent medium. The obtained polypyrrole–cellulose composite was chemically blended and showed flexible polymer properties while retaining the electronic properties of a conducting polymer. Addition of an ionic liquid such as trihexyl(tetradecyl)phosphonium bis(trifluoromethylsulfonyl)imide, enhanced the flexibility of the composite. The functional application of these materials in the electrochemically controlled release of a model drug has been demonstrated. This strategy opens up a new design for a wide spectrum of materials for smart electronic device applications wherein the functionality of doping and de-doping of conducting polymers is retained and their processability issue is addressed by exploiting an ionic liquid route. [ABSTRACT FROM AUTHOR]

A new method for the synthesis of main chain poly-imidazolium salts was developed from bisimidazole and silicon tetrachloride. These types of silicon-based poly-imidazolium salts are found to be among the most efficient metal-free heterogeneous catalysts (TOF = 90 h-1) for the fixation of CO2 with epoxides into cyclic carbonates under metal- and solvent-free conditions. [ABSTRACT FROM AUTHOR]

Methods for the transformation of carbohydrates into lactic acid (LA), which is a versatile platform chemical, have been widely investigated. These methods typically employ harsh reaction conditions, especially when water is used as a solvent. In the present study, a one-pot route that uses polymerizates of imidazole and epichlorohydrin ([IMEP]Cl) as catalysts to convert glucose to LA in water was described. The highest LA yield of 63% (mol%) was achieved with 99% glucose conversion at 100 °C in 50 mM NaOH solution. Compared to previous reports, the process has lower reaction temperatures and lower concentration of alkaline. A possible reaction mechanism was proposed that the coordination between the weak Lewis acid centers of the polymer with the electronegative oxygens on the intermediates efficiently facilitated the rate determining step during the reaction. This route allows for facile catalyst recovery and recycling while providing a new strategy for carbohydrate conversion. [ABSTRACT FROM AUTHOR]