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Global warming and climate change concerns are triggering worldwide interest for sustainable transformation of CO2 into useful chemicals. Here, a new and efficient multifunctional catalytic system for the cycloaddition of carbon dioxide with epoxides to synthesize cyclic carbonates under mild and solvent-free reaction conditions has been developed. The catalytic tests revealed that [P12,4,4,4]Br/MIL-53(Cr) (MIL: Materials of Institut Lavoisier) was the best and powerful catalytic system in the cycloaddition with excellent yields (96-99%) under solvent-free condition and 100 °C, 1.0 MPa for 2-3 h. The synergistic effect of anion and cation of ionic liquid [P12,4,4,4]Br as well as the chromium site of cocatalyst MIL-53(Cr) contributed to the excellent catalytic activity. The present catalytic system has several unique features such as simple operation, good to excellent yields, high catalytic activity, environmentally benign and safe. This study provides a sustainable and efficient synergistic strategy for chemical carbon dioxide fixation via the combination of ionic liquids and metal-organic frameworks. [ABSTRACT FROM AUTHOR]

Abstract: A supported ionic liquid ILCF3SO3@SiO2 was synthesized and used as a highly efficient catalyst in the Paal-Knorr reaction for the preparation of pyrroles. The heterogeneous catalyst could be easily recovered and recycled for five times without noticeable loss of catalytic activity. Also a possible reaction mechanism is provided.Graphical Abstract: [ABSTRACT FROM AUTHOR]

A series of silica-supported functionalized ionic liquids catalysts have been prepared and tested in the oxidative conversion of alcohols to nitriles with HO as the oxidant. The features of this heterogeneous reaction system were studied by tuning various reaction parameters including catalyst selection, amount of the catalyst, and effect of solvents. Among the catalysts, FeCl-IL-SiO exhibited the highest efficiency in direct oxidation of alcohols to nitriles under the optimized condition along with good recycle performance. Also, a possible catalytic mechanism is provided. Graphical abstract: [ABSTRACT FROM AUTHOR]

In this work, a functionalizing active species 4-methylbenzenesulfonic acid-based IL on silica gel (IL-SOH-SiO) has been prepared, and characterized by FT-IR, XRD, TGA, SEM and EDX spectra. Then, IL-SOH-SiO was utilized as an efficient and heterogeneous catalyst for the synthesis of indoles via the one-pot Fischer reaction of phenyl hydrazines with ketones or aldehydes at room temperature. The heterogeneous catalyst could be recovered easily by filtration and reused many times without significant loss of its catalytic activity. Graphical Abstract: [ABSTRACT FROM AUTHOR]

A simple, efficient, and eco-friendly procedure for the epoxidation of alkenes to epoxides with HO catalyzed by Co(OAc) in ionic liquid [Cpy][PF] has been developed. The reactions were carried out with alkene, Co(OAc) (0.1 mmol), [Cpy][PF] (10 mL), and HO (30 %, 11 mmol) at room temperature for 2-6 h. This atom-economical protocol affords the target products in good to high yields (88-98 %). The products can be separated by a simple extraction with organic solvent, and the catalytic system can be recycled and reused without loss of catalytic activity. Graphical abstract: A simple, efficient, and eco-friendly procedure for the epoxidation of alkenes to epoxides with HO catalyzed by Co(OAc) in ionic liquid [Cpy][PF] has been developed.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

A simple and efficient method for the oxidation of primary and secondary alcohols to the corresponding aldehydes and ketones with HO/(NH4)MoO4HO using the PEG-DIL/methylcyclohexane temperature-dependent biphasic system has been developed. The product can be easily isolated by a simple decantation, and the catalytic system can be recycled or reused without loss of catalytic activity. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

A facile and efficient synthesis of bibenzyl and biaryl derivatives by reductive homocoupling reaction is described. Treatment of benzyl and aryl halides with metallic zinc and copper powder in the presence of a catalytic amount of [Cmim][CuCl] under ligand- and base-free conditions gives the corresponding bibenzyls and biaryls in good to high yields. The product can be isolated by a simple extraction with organic solvent, and the catalytic system can be recycled or reused without any significant loss of catalytic activity. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

A concise, efficient method to sulfonyl quinones and sulfonyl-1,4-diols through Ir-catalyzed C-S coupling of quinones with sulfonyl chloride has been developed. Thus, this methodology proves its value as a versatile synthetic tool for a broad range of sulfonyl quinones, producing good to excellent yields. Graphical Abstract: [ABSTRACT FROM AUTHOR]