Six ionic liquid (IL)-modified dyes were synthesized and characterized. Compared to the methyl red and methyl orange, these IL-modified [MR]
- or [MO]
-based dyes exhibit lower melting points and enhanced solubility, and can be used as sensitive indicators towards free proton in both aqueous and non-aqueous solutions. This work also supplies a new concept of developing novel modified materials with the ILs.

★★★☆☆ Analyst, 2011, 136, 1302–1304

A practical method for the synthesis of carbamates from ureas and organic carbonates was developed with 100% atom economy using La2O3/SiO2 as catalyst without any additional solvent. The scope of the protocol is demonstrated in the synthesis of 14 carbamates with various functional groups in excellent yields (76–95%).

Keywords Atom economy; carbamates; carbonates; clean synthesis; lanthana; urea derivatives

Guo XG,Shang JP,Li J,et al. Green And Practical Synthesis Of Carbamates From Ureas And Organic Carbonates[J]. Synthetic Communications,2011,41:1102-1111.

Nine 1-allyl-3-alkylimidazolium ([ACnIm]) or 1-vinyl-3-alkylimidazolium ([VCnIm]) dicyanamides (DCA) were prepared and characterized, and their physicochemical properties were studied in detail. Except for [AVIm]DCA and [AC4Im]DCA, the other dicyanamides with hexyl or longer alkyl chains on the cation exhibited the characteristic of hydrophobicity. Among them, [AC8Im]DCA and [AC10Im] DCA were found to possess similar densities to water, i.e. 1.007 g cm
3 and 0.988 g cm
3 at 25 C, respectively. Interestingly, a reversible phase reversion of a [AC8Im]DCA/H2O mixture was observed as the temperature varied. These environmentally-friendly liquid materials have potential applications as precursors for syntheses of conducting polymeric materials.

★★★☆☆ J. Mater. Chem., 2011, 21, 6864–6868

A novel Au&Pd/Fe(OH)x catalyst with separate Au and Pd active sites was designed and synthesized. It was found for the first time that total conversion of CO + H2 could be achieved at room temperature over this catalyst. The separate Au and Pd sites in Au&Pd/Fe(OH)x catalyst were confirmed by the XPS, XRD, 197Au MÖssbauer characterizations and the activity measurements, although a small amount of Au–Pd alloy formed after the catalyst was calcined at 500 ℃.

Keywords: Gold; Palladium; Bimetal; Separate active sites; Co-oxidation

★★★☆☆ Qiao BT,Wang AQ,Masashi Takahashi,et al. A Novel Au&pd/fe(oh)x Catalyst For Co + H2 Co-oxidations At Low Temperatures[J]. Journal Of Catalysis,2011,279:361-365.

A series of catalysts of magnetic iron oxide containing Ni with different nickel content were prepared with co-precipitation method and tested in the syntheses of N-substituted carbamates from various amines and alkyl carbamates. Under the optimized reaction conditions, various N-substituted carbamates were successfully synthesized with 90–98% isolated yield. The catalyst could be recovered based on the magnetic property of the catalyst and reused for five runs without deactivation. The catalysts were characterized with X-ray photoelectron spectroscopy, X-ray diffraction, temperature-programmed reduction, temperature-programmed desorption, and Mössbauer spectroscopy analyses. The results showed that the catalytic activity may be derived from the delicate synergy between Ni and Fe species resulted in specific basic sites. Quasi in situ FT-IR and isotopic tracer revealed that the formation of substituted urea was the key step and the N-substituted carbamate was formed via further alcoholysis of the substituted urea.

Keywords: Non-phosgene; Carbamate; Carbonylation; Magnetic iron oxide

★★★☆☆ J. Shang et al. / Journal of Catalysis 279 (2011) 328–336