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Coordination cages have been widely reported to bind a variety of guests, which are useful for chemical separation. Although the use of cages in the solid state benefits the recycling, the flexibility, dynamicity, and metal-ligand bond reversibility of solid-state cages are poor, preventing efficient guest encapsulation. Here we report a type of coordination cage-integrated solid materials that can be swelled into gel in water. The material is prepared through incorporation of an anionic FeII4L6 cage as the counterion of a cationic poly(ionic liquid) (MOC@PIL). The immobilized cages within MOC@PILs have been found to greatly affect the swelling ability of MOC@PILs and thus the mechanical properties. Importantly, upon swelling, the uptake of water provides an ideal microenvironment within the gels for the immobilized cages to dynamically move and flex that leads to excellent solution-level guest binding performances. This concept has enabled the use of MOC@PILs as efficient adsorbents for the removal of pollutants from water and for the purification of toluene and cyclohexane. Importantly, MOC@PILs can be regenerated through a deswelling strategy along with the recycling of the extracted guests. The efficient encapsulation of guests by coordination cages in the solid state is prevented by their flexibility, dynamicity, and metal-ligand bond reversibility. Here, the authors report coordination cages integrated into poly(ionic liquid)s to control swelling and mechanical properties of the gels and develop efficient and regenerable supramolecular separation materials. [ABSTRACT FROM AUTHOR]

The one-pot reactions of CO2, epibromohydrin, and phenols, thiophenols, or carboxylic acids catalyzed by 1-butyl-3-[(3-hydroxyphenyl)methyl]imidazolium bromide were investigated. Three kinds of cyclic carbonates with ether, thioether, or ester groups were synthesized under mild reaction conditions in good-to-high yields. Reaction-mechanism studies indicated that the proton exchange between the alkoxide formed through the ring-opening reaction of epibromohydrin with 1-bromo-3-phenoxy-2-propanol plays a crucial role in this synthetic route. The catalyst 1-butyl-3-[(3-hydroxyphenyl)methyl]imidazolium bromide was transformed to the corresponding cyclic-carbonate-functionalized ionic liquid during the reaction. This transformation did not affect its catalytic performance in the reaction. [ABSTRACT FROM AUTHOR]

A selective procedure for the synthesis of 5-substituted N-aryloxazolidinones by the coupling of epoxides with arylcarbamates catalyzed by ionic liquids has been developed. The effects of reaction time, reactant molar ratio, amount of catalyst, and temperature were investigated. Under the optimal reaction conditions, BmimOAc exhibited efficient catalytic activity compared with other ionic liquids leading to the formation of 5-substituted N-aryloxazolidinones in excellent yields. In addition, chiral 5-substituted oxazolidinones were synthesized by this procedure in good-to-excellent yields with enantiomeric excesses in excess of 99.9 % starting from chiral terminal epoxides. A possible reaction mechanism is discussed in accord with the results obtained by 1H NMR spectroscopy and DFT calculations, which indicate the cooperative activation by BmimOAc through the formation of hydrogen bonds with the substrates. [ABSTRACT FROM AUTHOR]

An intermolecular synergistic catalytic combination of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and a DBU-derived bromide ionic liquid has been developed for the conversion of CO2, epoxides, and amines under metal- and solvent-free conditions. Various 3-aryl-2-oxazolidinones are produced in moderate to excellent yields within a short reaction time. NMR spectroscopy and DFT calculations demonstrate that DBU as a hydrogen bond acceptor and the ionic liquid as a hydrogen bond donor activate the substrates cooperatively by inducing hydrogen bonds to promote the reaction effectively. Based on these results, a possible reaction mechanism on the synergistic catalysis of DBU and the ionic liquid is proposed. In addition, the reaction of CS2, ethylene oxide, and aniline catalyzed by the combination of DBU and the DBU-derived ionic liquid also proceeds smoothly, which opens a hitherto unreported route to [1,3]dithiolan-2-ylidenephenylamine in a straightforward way. [ABSTRACT FROM AUTHOR]

We have investigated the reactions of cyclic carbonates/trithiocarbonate and aromatic amines in the presence of a basic ionic liquid, 1-butyl-3-methylimidazolium acetate (BmimOAc), which produced various cyclic carbamates/dithiocarbonimidates in fairly good to excellent yields. The use of BmimOAc as catalyst here not only offers an effective approach to the synthesis of the target compounds, but also avoids the use of conventional toxic materials. By means of the reactions of cyclic carbonates and aromatic amines, 3-aryloxazolidin-2-ones, 3,3′-aryldioxazolidin-2-ones and 3-aryl[1,3]oxazinan-2-ones could be synthesized. NMR spectroscopy and DFT calculations revealed that both the cation and the anion of BmimOAc activate cooperatively the substrates in these reactions by means of inducing hydrogen bonding. In addition, condensation reactions of ethylene trithiocarbonate and aromatic amines also proceeded very well in the presence of the BmimOAc catalyst, which opened a hitherto unreported route to [1,3]dithiolan-2-ylidene-arylamine derivatives in a straightforward way. [ABSTRACT FROM AUTHOR]

[Display omitted] Ionic liquids/organic bases synergistically catalyze the cycloaddition of CO 2 and epoxides under atmospheric pressure with high activity. • Ionic liquids/organic bases intermolecular synergistic catalytic system was developed for CO 2 cycloaddition under atmospheric pressure. • The synergistic effect presumably ascribes to the activation of epoxides by ionic liquids and CO 2 by organic bases. • Secondary amines activate CO 2 to form carbamic acids, and tertiary amines activate CO 2 to form bicarbonate salts with the aid of water. • Plausible synergistic catalyzed mechanisms are proposed based on the NMR, FT-IR investigations and DFT calculations. An intermolecular synergistic catalytic system consisting of ionic liquids and organic bases is developed for the cycloaddition of CO 2 and epoxides. This strategy realizes the cycloaddition takes place under atmospheric pressure of CO 2 with high activity. NMR, FT-IR spectroscopy and DFT calculations are applied to investigate the synergistic effect and reaction mechanism on molecules. Plausible ionic liquids/secondary amines and ionic liquids/tertiary amines catalyzed mechanisms are proposed and further confirmed by more detailed DFT calculations including reaction pathways and energy profiles, respectively. The procedure reported here represents a facile, cost-effective and energy-efficient route for chemical fixation of CO 2 into 5-membered cyclic carbonates. [ABSTRACT FROM AUTHOR]

A series of imidazolium ionic liquids were designed and synthesized by the reaction of imidazole derivatives with alkyl bromides. These ionic liquids were applied to catalyze the reaction of CO 2 and epoxides. A detailed investigation was carried out on the relationship between catalytic activities and catalyst structures. The result showed that phenolic hydroxyl-functionalized imidazolium ionic liquids containing both phenolic hydroxyl and C2-H were highly efficient catalysts. Meanwhile, the spatial positions of the phenolic hydroxyl and C2-H in the imidazolium also exhibited great effect on the catalytic efficiencies, and the order of catalytic activity was meta -isomer > ortho -isomer > para -isomer. NMR titration and DFT calculations showed a synergetic effect, which C2-H and phenolic hydroxyl cooperatively activated epoxides by hydrogen bonds, was crucial for the reaction to proceed smoothly under mild conditions. In addition, the TOF of the most active catalyst 3-(3-phenolic hydroxyl)-1-butyl-imidazolium bromide ( IL-2 ) reached to 900 h −1 in the reaction of CO 2 and epichlorohydrin under the reaction conditions of 0.1 mol% catalyst, 1 MPa CO 2 , 120 °C and 1 h. [ABSTRACT FROM AUTHOR]

An efficient convenient procedure for the synthesis of 3-aryl-2-oxazolidinones from 2-(arylamino) alcohols and diethyl carbonate (DEC) catalyzed by ionic liquids is described. The effects of reaction time, amount of catalyst and temperature were investigated. Excellent yields of products were obtained under the optimized reaction conditions, when using BmimOAc as a catalyst. An intermediate ethyl 2-(phenyl amino) ethyl carbonate was isolated and characterized. 1 H NMR spectroscopy and DFT calculations indicated that BmimOAc cooperatively activate the substrates through hydrogen bonding with its anion and cation sites. According to these results, a possible reaction mechanism was discussed. [ABSTRACT FROM AUTHOR]

The title compounds are prepared by conversion of CO2/CS2, epoxides, and amines under solvent- and metal-free conditions. [ABSTRACT FROM AUTHOR]

The reaction of cyclic carbonates with a variety of aromatic and heteroaromatic amines is advantageously achieved in [bmim]OAc as catalytic solvent to yield cyclic carbamates. [ABSTRACT FROM AUTHOR]