Oxidation of Primary Amines to Oximes with Molecular Oxygen using 1,1-Diphenyl-2-picrylhydrazyl and WO₃/Al₂O₃ as Catalysts

The oxidative transformation of primary amines to their corresponding oximes proceeds with high efficiency under molecular oxygen diluted with molecular nitrogen (O₂/N₂ = 7/93 v/v, 5 MPa) in the presence of the catalysts 1,1-diphenyl-2-picrylhydrazyl (DPPH) and tungusten oxide/alumina (WO₃/Al₂O₃). The method is environmentally benign, because the reaction requires only molecular oxygen as the terminal oxidant and gives water as a side product. Various alicyclic amines and aliphatic amines can be converted to their corresponding oximes in excellent yields. It is noteworthy that the oxidative transformation of primary amines proceeds chemoselectively in the presence of other functional groups. The key step of the present oxidation is a fast electron transfer from the primary amine to DPPH followed by proton transfer to give the α-aminoalkyl radical intermediate, which undergoes reaction with molecular oxygen and hydrogen abstraction to give α-aminoalkyl hydroperoxide. Subsequent reaction of the peroxide with WO₃/Al₂O₃ gives oximes. The aerobic oxidation of secondary amines gives the corresponding nitrones. Aerobic oxidative transformation of cyclohexylamines to cyclohexanone oximes is important as a method for industrial production of ε-caprolactam, a raw material for Nylon 6

Ring-Opening Polymerization of THF by Aryloxo-Modified (Imido)vanadium(V)-alkyl Complexes and Ring-Opening Metathesis Polymerization by Highly Active V(CHSiMe₃)(NAd)(OC₆F₅)(PMe₃)₂

Ring-opening polymerizations of THF using V­(NR)­(CH₂SiMe₃)­(OAr)₂ [R = 2,6-Me₂C₆H₃, 1-adamantyl (Ad), Ph; Ar = 2,6-Me₂C₆H₃, C₆F₅] proceeded in a living manner in the presence of [Ph₃C]­[B­(C₆F₅)₄], affording high molecular weight polymers with low PDI (<i>M</i>_w/<i>M</i>_n) values: the observed activity (initiation efficiency) was affected by the arylimido and aryloxo ligands employed. A new vanadium­(V)-alkylidene, V­(CHSiMe₃)­(NAd)­(OC₆F₅)­(PMe₃)₂, prepared from V­(NAd)­(CH₂SiMe₃)₂(OC₆F₅) by α-hydrogen elimination in <i>n</i>-hexane in the presence of PMe₃ at 25 °C, exhibited remarkable catalytic activity for ring-opening metathesis polymerization of norbornene: the activity at 25 °C was higher than those by the reported vanadium­(V)-alkylidenes and ordinary Mo­(CHCMe₂Ph)­(N-2,6-^<i>i</i>Pr₂-C₆H₃)­(O^<i>t</i>Bu)₂

Aerobic Oxidative Esterification of Aldehydes with Alcohols by Gold–Nickel Oxide Nanoparticle Catalysts with a Core–Shell Structure

Oxidative esterification of aldehydes with alcohols proceeds with high efficiency in the presence of molecular oxygen on supported gold–nickel oxide (AuNiO_<i>x</i>) nanoparticle catalysts. The method is environmentally benign because it requires only molecular oxygen as the terminal oxidant and gives water as the side product. The AuNiO_<i>x</i> nanoparticles have a core–shell structure, with the Au nanoparticles at the core and the surface covered by highly oxidized NiO_<i>x</i>. Aerobic oxidative esterification of methacrolein in methanol to methyl methacrylate is an important industrial method for the production of polymethyl methacrylate

Molecular Aggregation States and Physical Properties of Syndiotactic Polystyrene/Hydrogenated Polyisoprene Multiblock Copolymers with Crystalline Hard Domain

Molecular aggregation structure and mechanical as well as thermal properties of novel well-defined multiblock copolymers consisting of crystalline syndiotactic polystyrene (sPS) and rubbery hydrogenated polyisoprene (hPIp) were investigated. The morphology and crystalline ordered structure of the multiblock copolymer films prepared by solvent casting from 1,2-dichlorobenzene solution depended on the volume fraction of sPS (VF_sPS) and number of blocks. The multiblock copolymer films exhibited ordered morphology with low crystallinity. The crystallinity of the sPS reduced with decreasing the VF_sPS. The pentablock copolymer produced more ordered morphology and less crystallinity than the triblock copolymers. The anisotropic orientation and mechanical stability of the δ form sPS crystals in the spherical sPS domains during uniaxial stretching were demonstrated. Tensile testing and dynamic mechanical analysis indicated that these multiblock copolymer films with appropriate sPS fraction are strong, tough, and elastic and thus could be potential candidates for a new type of thermoplastic elastomer with discrete crystalline hard domains

Eliminated BMC transplantation-induced tissue recovery by HMGB1-inhibition.

<p>Reduced extracellular collagen deposition (<b>A–C;</b> picrosirius red = red), increased capillary density (<b>D–F;</b> Isolectin B4 = red), and increased proliferation (<b>G–I;</b> Ki67 = red; nuclei = blue; cTnT = green) were observed in the border areas at day 28 after BMC transplantation (BMC group), compared to the PBS control (CON group). These effects were all abolished by anti-HMGB1 antibody neutralization (AB group), but not by control IgG administration (IgG group). Representative images of only BMC and AB groups are present (see <b><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0076908#pone.0076908.s002" target="_blank">Figure S2</a></b> for additional images). Scale bars = 50 µm in <b>A, B, G, H</b> and 30 µm in <b>D, E</b>. *:<i>p</i><0.05 <i>versus</i> the CON group, ^†:<i>p</i><0.05 <i>versus</i> the BMC group, ^‡:<i>p</i><0.05 <i>versus</i> the IgG group, mean±SEM for n = 5∼7 in each group.</p

Modulation of innate immunity by BMC transplantation via released HMGB1.

<p>Accumulation of CD68⁺ pan-macrophages (<b>A</b>), CD86⁺ classically-activated pro-inflammatory M1 macrophages (<b>B</b>), and CD163⁺ alternatively-activated anti-inflammatory M2 macrophages (<b>C</b>) in the border areas at day 3 after each treatment was assessed by immunolabeling. See <b><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0076908#pone.0076908.s003" target="_blank">Figure S3</a></b> for representative images. Myocardial expression of <i>IL-10</i> (<b>D</b>), <i>IL-1β</i> (<b>E</b>)), and <i>TNF-α</i> (<b>F</b>) at day 3 after each treatment was measured by quantitative RT-PCR. *:<i>p</i><0.05 <i>versus</i> the CON group, ^†:<i>p</i><0.05 <i>versus</i> the BMC group, mean±SEM for n = 5∼7 in each group.</p

Poor donor cell survival and HMGB1 leakage after BMC transplantation.

<p>(<b>A</b>) Quantitative PCR for the male specific <i>sry</i> gene showed that the survival of male donor cells in female hearts was poor similarly in the BMC (BMC injection), IgG (BMC+control IgG injection), and AB (BMC+anti-HMGB1 antibody injection) groups at both days 3 and 28; n = 5∼7 in each point. (<b>B</b>) Clusters of DiI-labeled (red) donor BMCs were detected in the heart at day 3 after BMC transplantation. A higher magnification image of the yellow frame is shown. Green = cardiomyocytes (cTnT); blue = nuclei (DAPI). Scale bar = 300 µm. (<b>C</b>) ELISA showed that the circulating HMGB1 level was increased at 1 hour in the BMC group compared to the PBS injection control (CON group). *:<i>p</i><0.05 <i>versus</i> the CON group, mean±SEM for n = 5 each.</p

Relationship of cell-surface proteins and retention of BMMNC.

<p>The expression profiles of cell-surface proteins, including integrin and selectin ligand, on pre-injection BMMNC and BMMNC in the coronary effluent (collected over the five-minute duration post-IC injection of 8x10⁶ BMMNC) were compared by flow cytometric analysis. No difference was found in any of the surface proteins investigated (n = 6 hearts were studied, unpaired T-test), suggesting that these cell-surface proteins are not critical for retention in normal hearts.</p

Different distribution of retained BMMNC between ventricular layers.

<p>At 5 minutes after IC injection of 8x10⁶ PKH67-labeled BMMNC, the number of donor cells within the endocardium-side myocardium, central myocardium and epicardium-side myocardium were counted in cross-section of immunohistolabelling samples. The concentration of cells progressively increased from the epicardium to the endocardium (n = 4, <i>p</i><0.0001, One-way ANOVA followed by Bonferroni post-hoc test).</p

Initial retention of MSC after IC injection.

<p>(<b>A</b>) Following IC injection of 1×10⁶ bone marrow-derived rat MSC into a rat heart using the same model, reduced numbers of donor MSC were found in the coronary effluent within the first minute, in comparison with IC injection of the same number of BMMNC (refer to <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0158232#pone.0158232.g001" target="_blank">Fig 1</a>). n = 8 in each cell-type, <i>p</i><0.001, Two-way ANOVA followed by Bonferroni post-hoc test; *<i>p</i><0.05 versus Epicardium, ^†p<0.05 versus Myocardium. (<b>B</b>) The coronary effluent flow rate decreased immediately following IC injection of MSC but gradually recovered to the base line by 10 minutes (n = 8). (<b>C</b>) The distribution of MSC diameters prior to injection and in the coronary effluent were quantified and expressed as fractions (n = 8). There appeared to be a leftwards shift in the diameters of the coronary effluent cell population. (<b>D</b>) With knowledge of the cell numbers of each cell diameter, the retention efficiency of MSC having each diameter was calculated (n = 8). Larger MSC subsets were likely to be more frequently retained, but the retention rate was plateaued at ~80% with cell diameters ≥ 9 μm.</p