This paper reports an effective route for the syntheses of N-substituted dicarbamates from dialkyl carbonates and polyurea derivatives, in which polyurea derivatives could be successfully synthesized from aliphatic diamines and CO2 in the absence of any catalyst. Under the optimized reaction conditions, various N-substituted carbamates were successfully synthesized with 93–98% isolated yields over a MgO–ZnO catalyst. The catalyst could be reused for several runs without deactivation. The catalysts were characterized with X-ray photoelectron spectroscopy, X-ray diffraction and temperature-programmed desorption.

★★★★☆ Green Chem., 2012, 14, 2899–2906

Magnetic binary MgFe oxides were prepared by co-precipitation method, characterized and tested in the synthesis of 2-oxazolidinones from epoxides and carbamates. The catalytic results showed that the catalyst with Mg/Fe molar ratio of 1 and calcined at 400 °C exhibited superior catalytic activity. The catalyst could be magnetically separated, recycled and reused for five runs without noticeable deactivation. Under the optimized conditions, various 2-oxazolidinones derivatives were successfully synthesized with good to excellent isolated yields.

Keywords: 2-oxazolidinone; Epoxide; Carbamate; Solid base; Magnetic oxides

★★★☆☆ J. Shang et al. / Catalysis Communications 28 (2012) 13–17

CO₂/H₂ was successfully employed in alkylation reactions by performing CO₂ reduction and amine N-methylation in one-pot. In the presence of a simple CuAlO_x catalyst, N-methyl or N,N-dimethyl amines with different structures can be selectively synthesized with up to 96% yields by applying amine, nitrobenzene and nitrile as starting materials.

★★★☆☆ Cui XJ,Dai XC,Zhang Y,et al. Methylation Of Amines, Nitrobenzenes And Aromatic Nitriles With Carbon Dioxide And Molecular Hydrogen[J]. Chemical Science,2014,5:649-655.

The electroreduction of oxygen was firstly studied on Ag/Co₃O₄–C in alkaline media prepared by depositing Ag on Co₃O₄ modified carbon (Co₃O₄–C). The Ag/Co₃O₄–C composite not only displayed relatively large electrochemical active surface area (ESA), high catalytic activity towards oxygen reduction reaction (ORR), but also exhibited good methanol tolerance and stability in alkaline media. Ag/Co₃O₄–C could be a valuable catalyst for ORR and be applied to alkaline fuel cells and metal–air batteries.

Keywords: Silver; Cobalt oxide; Oxygen reduction reaction; Alkaline media

★★★★☆ Wang Y,Lu XJ,Liu Y,et al. Silver Supported On Co3o4 Modified Carbon As Electrocatalyst For Oxygen Reduction Reaction In Alkaline Media[J]. Electrochemistry Communications,2013,31:108-111.

Because of its sensitivity to chemical and electrostatic characteristics, nitrile group as an infrared (IR) probe to monitor the local structure, folding kinetics, and electrostatic environment of protein, or solvation of molecular solvents, has attracted increasing attention. Herein, by choosing benzonitrile and imidazolium ionic liquids (ILs) as the IR probe and model ILs, respectively, we report that the nitrile stretching vibration (νCN) could be utilized as a simple and substantial IR probe to monitor the local environment of ILs such as hydrogen bonding (H-bonding) as well as intrinsic electric field. In 1-alkyl-3-methylimidazolium-based non-hydroxyl ILs, the νCN is in a “free” state, and is less affected by the alkyl chain, while it significantly decreases with the effective anion charge. In 1-(2-hydroxyethyl)-3-methylimidazolium-based hydroxyl ILs, however, a distinct anion-dependent νCN forming H-bonding with the hydroxyl is also observed besides the “free” νCN band. The “free” component of νCN can be further employed to determine the intrinsic electric field in both non-hydroxyl (directly) and hydroxyl (indirectly by subtracting H-bonding contribution) ILs by using vibrational Stark effect. Moreover, the result suggests that benzonitrile is preferentially located in the charge domain in ILs and it could be a more suitable probe to report the ionic network rather than the nonpolar domain in ILs.

★★★☆☆ Zhang SG,Zhang Y,Ma XY,et al. Benzonitrile As A Probe Of Local Environment In Ionic Liquids[J]. J. Phys. Chem. B,2013,117:2764-2772.

By applying a simple TiO₂–(NH₄)₂S₂O₈ system and promoted by UV light, the three-component reactions of cyclic ether, aniline and aldehyde can be progressed efficiently. 29 substituted amines with different structures were synthesized with up to 97% isolated yields. Isotope effect study revealed that the ratedetermining step might be the nucleophilic addition step but not radical generation.

Keywords: Amine; Imine; Heterogeneous catalysis; Light

★★★★☆ Lina Zhang,Deng YQ,Shi F. Light Promoted Aqueous Phase Amine Synthesis Via Three-component Coupling Reactions[J]. Tetrahedron Letters,2013,54:5217-5219.

A simple and efficient Pd/Al₂O₃-NR-RD catalyst was prepared by depositing palladium on a shape controllable Al₂O₃-NR support through a two-step process that involves hydrothermal synthesis of Al₂O₃-NR_s followed by reductive-deposition of palladium. This catalyst showed high activity in the catalytic formylation of amines by CO₂–H₂ under mild conditions with up to 96% yield.

★★★★☆ Cui XJ,Zhang Y,Deng YQ,et al. Amine Formylation Via Carbon Dioxide Recycling Catalyzed By A Simple And Efficient Heterogeneous Palladium Catalyst[J]. Chemical Communications,2013,50:189-191.

The electroreduction of oxygen of MnO_x-Co₃O₄/C was firstly studied in alkaline media. The MnO_x-Co₃O₄/C showed better electrocatalytic activity towards ORR than MnO_x/C and Co₃O₄/C. Compared to Pt/C, MnO_x-Co₃O₄/C showed better methanol tolerance and durability in alkaline solution. Thus, the MnO_x-Co₃O₄/C catalyst had potential for applications in metaleair batteries and alkaline fuel cells.

Keywords: Manganese oxides; Cobalt oxides; Oxygen reduction reaction; Alkaline media

★★★☆☆ Wang Y,Ma XY,Lu LJ,et al. Carbon Supported Mnox–co3o4 As Cathode Catalyst For Oxygen Reduction Reaction In Alkaline Media[J]. International Journal Of Hydrogen Energy,2013,38:13611-13616.

Electric fields of ionic liquids (ILs) were investigated by vibrational Stark effect spectroscopy using ethyl thiocyanate as a probe molecule. It was found that the stretching vibration of C≡N in nonhydroxyl ILs originates exclusively from the intrinsic electric fields, which are on average 3.0 MV cm^-1 higher than those of molecular solvents. In contrast, in the case of hydroxyl functional ILs, hydrogen bonding as well as the electric field contribute to the IR shift of C≡N.

★★★☆☆ Zhang SG,Zhang Y,Deng YQ. Investigation Of The Intrinsic Electric Field Of Nonhydroxyl And Hydroxyl Ionic Liquids By Vibrational Stark Effect Spectroscopy[J]. Rsc Advances,2013,3:11480-11484.

As the sustainable and promising hydrogen source, here, glycerol was directly used as the hydrogen source for the reductive amination of alcohol using nitrobenzene as the starting material. The amination of alcohols, especially aliphatic alcohols with different structures, was realized, and mono- or disubstituted amines were synthesized with excellent yields. The reaction mechanism was also explored.

KEYWORDS: amines, alcohols, N-alkylation, glycerol, renewable, catalysis

★★★☆☆ xinjiang Cui,Youquan Deng,Feng Shi. Reductive N‑alkylation Of Nitro Compounds To N‑alkyl And N,n‑dialkyl Amines With Glycerol As The Hydrogen Source[J]. Acs Catalysis,2013,3:808-811.