Ab‐Initio study of Helium‐small carbon cage systems

The traditional method for opening the electron shells of noble gas atoms involves a strong electronegative atom or group. However, this approach is limited to only heavy noble‐gas atoms, such as Kr and Xe. In this paper, we performed accurate calculations of He@C₈H₈ and He@C10H16 and showed the possibility of opening the electron shell of a light noble‐gas atom. © 2012 Wiley Periodicals, Inc.     

Colorimetric detection of peroxynitrite-induced DNA damage using gold nanoparticles, and on the scavenging effects of antioxidants

We describe a rapid and convenient colorimetric method for the detection of oxidative DNA damage caused by peroxynitrite (ONOO^?) using unmodified gold nanoparticles (AuNPs). AuNPs are stable in the presence of single-stranded DNA (ssDNA) against the aggregation induced by a high ionic strength. If adsorbed ssDNA are cleaved by ONOO^? to form smaller fragments, the AuNPs rapidly aggregate due to electrostatic attraction. As a result, the color of the solution changes from red to blue, and this can be seen with bare eyes. We also have evaluated the activity of the antioxidants gallic acid, ascorbic acid and caffeic acid to scavenge ONOO^?. This method therefore also can be applied to screen for anti-oxidation drugs and agents.

Synthesis of gold nanoparticles on the surface of pyrolytic graphite using penicillin as a stabilizing reagent and the catalytic oxidation of α-naphthylamine

Electrochemical synthesis of gold nanoparticles on the surface of pyrolytic graphite using penicillin as a stabilizing reagent was proposed. The gold nanoparticles were characterized by scanning electron microscopy, cyclic voltammetry, IR spectra, UV spectra, and powder X-ray diffraction spectra. The electro-chemical catalysis of penicillin for α-naphthylamine was demonstrated.     

Synthesis of Benzo[a]Phenanthro[9,10-e]-Cyclooctene

A phenanthrene-fused cyclooctatetraene, namely benzo[a]phenanthro[9,10-e]cyclooctene has been synthesized by employing the “Reich-Paquette” procedure.     

Total synthesis of (+)-valienamine and (−)-1-epi-valienamine via a highly diastereoselective allylic amination of cyclic polybenzyl ether using chlorosulfonyl isocyanate

The total synthesis of (+)-valienamine and (−)-1-epi-valienamine was concisely accomplished from readily available d-glucose via a highly diastereoselective amination of chiral benzylic ether using chlorosulfonyl isocyanate, intramolecular olefin metathesis, and diastereoselective reduction of cyclic enone using l-Selectride as the key steps.     

Palladium-catalyzed hydrodehalogenation of aryl halides using paraformaldehyde as the hydride source: high-throughput screening by paper-based colorimetric iodide sensor

Paraformaldehyde was employed as a hydride source in the palladium-catalyzed hydrodehalogenation of aryl iodides and bromides. High throughput screening using a paper-based colorimetric iodide sensor (PBCIS) showed that Pd(OAc)₂ and Cs₂CO₃ were the best catalyst and base, respectively. Aryl iodides and bromides were hydrodehalogenated to produce the reduced arenes using Pd(OAc)₂ and Pd(PPh₃)₄ catalyst. This catalytic system showed good functional group tolerance. In addition, it was found that paraformaldehyde is the hydride source and the reducing agent for the formation of palladium nanoparticles.     

A novel reaction of the ‘Huisgen zwitterion’ with benzofuran-2,3-diones: an efficient strategy for the synthesis of spirocyclic benzofuran-2-one derivatives

The nitrogen-based nucleophile generated from azodicarboxylate and triphenylphosphine displayed good reactivity toward benzofuran-2,3-diones to generate a variety of spirocyclic benzofuran-2-one derivatives. The reactions accommodate a number of benzofuran-2,3-diones and different dialkylazodicarboxylates to give the enriched functionalized 3-spirooxadiazole benzofuran-2-ones with moderate to good yields (up to 93%).     

Copper-catalyzed oxidative coupling of carboxylic acids with formamides for the synthesis of α,β-unsaturated amides

A novel and efficient protocol for the synthesis of α,β-unsaturated amides has been developed using catalytic amount of Cu(OAc)₂ and TBHP as an available oxidant. Oxidative coupling of various unsaturated carboxylic acids with N,N-disubstituted formamides was examined to furnish the desired products in good yields.     

Palladium-catalyzed C–S bond formation by using N-amido imidazolium salts as ligands

N-Amido imidazolium salt was employed as a ligand in the palladium-catalyzed cross-coupling reaction of aryl halides and thiols, and showed good activity in the formation of thioether. The best combination for the coupling with aryl bromides was N-amido imidazolium salt 2 and NaHMDS, and that for the coupling with aryl iodides was N-amido imidazolium salt 1 and KO^tBu. The coupling reactions were conducted in the presence of Pd(OAc)₂ (1 mol %) in DMSO at 80 °C for 12 h.     

Structure and Activity of RNase A in Sodium Dodecyl Sulphate Solutions

The structure and activity of RNase A in sodium dodecyl sulphate solutions were investigated at 25.0±0.1 and pH 7.00. The results show that with increasing sodium dodecyl sulphate concentration, the structure of RNase A is collapsed gradually, however, the activity of RNase A is first increased and then decreased. This is mainly due to the different effect of SDS at different SDS concentration.