Recyclable Magnetic Nanoparticle‐Supported Iodoarene Catalysts for Oxidation of 4‐Alkoxyphenols to Quinones

Iodoarene catalysts immobilized on magnetite (Fe3O4) were developed. The reactivity of catalysts 4 a and 4 b were similar to that of 4‐iodophenoxyacetic acid (3) for the oxidation of 4‐alkoxyphenols in the presence of Oxone® as a co‐oxidant to give the corresponding p‐quinones in high yields. In addition, 4 b was readily recovered by the use of an external magnet and was recycled up to eight times. This is the first example of a magnetic, nanoparticle‐supported iodoarene catalyst.Drawn to it like a magnet: The reactivity of iodoarene catalysts immobilized on magnetite (Fe3O4) were similar to that of 4‐iodophenoxyacetic acid for the oxidation of 4‐alkoxyphenols in the presence of Oxone® as a co‐oxidant to give the corresponding p‐quinones in high yields. These catalysts were readily recovered by the use of an external magnet and were recycled up to eight times.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137564/1/ajoc201600036-sup-0001-misc_information.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137564/2/ajoc201600036_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137564/3/ajoc201600036.pd

Stereoselective Total Synthesis of Myriocin Using Rh(II)-Catalyzed C–H Amination Followed by Alkylation

The stereoselective total synthesis of myriocin was achieved by using the Du Bois Rh(II)-catalyzed C−H amination of sulfamate 6 and a subsequent alkylation. The reaction of sulfamate 6 with PhI(OAc)2 and MgO in the presence of Rh2(OAc)4 gave oxathiazinane N,O-acetal as the sole product in high yield. Alkylation of the N,O-acetal using vinylmagnesium bromide in the presence of ZnCl2 proceeded stereoselectively to provide an oxathiazinane bearing a quaternary chiral center in high yield. This route includes the first application of the Du Bois procedure for the construction of a quaternary chiral center

An efficient synthesis of cycloalkane-1,3-dione-2-spirocyclopropanes from 1,3-cycloalkanediones using (1-aryl-2-bromoethyl)dimethylsulfonium bromides: application to a one-pot synthesis of tetrahydroindol-4(5H)-one

An efficient synthesis of cyclohexane- and cyclopentane-1,3-dione-2-spirocyclopropanes from 1,3-cycloalkanediones using sulfonium salts was achieved. The reaction of 1,3-cycloalkanediones with (1-aryl-2-bromoethyl)dimethylsulfonium bromides and powdered K2CO3 in EtOAc provided the corresponding spirocyclopropanes in high yields. Furthermore, a one-pot synthesis of tetrahydroindol-4(5H)-one from 1,3-cyclohexanedione was achieved by using the present protocol and a sequential ring-opening cyclization of spirocyclopropane with a primary amine

Diquark Corrleations in the nucleon structure function

The nucleon structure functions are studied with a special emphasis on diquark correlations inside the nucleon. Assuming a phenomenological diquark-quark model of the nucleon at the low energy hadronic scale, we calculate the leading twist contributions to the nucleon structure functions. We take the Nambu and Jona-Lasinio model for the calculation of the quark distributions in the diquarks, and use the convolution method for the diquark scattering process. The resulting quark distributions are evolved to the experimental momentum scale using the perturbative QCD. We discuss the flavor dependence of the nucleon structure functions and the importance of the quark-quark correlations for the understanding of the nucleon structure.Comment: 18pages, TMU-NT-931001. 6 figures included in a separate uuencoded postscript file

Meson Structure in Deep Inelastic Scattering

We study the deep inelastic structure functions of mesons within the Nambu and Jona-Lasinio model. We calculate the valence quark distributions in $\pi$, $K$, and $\rho$ mesons at the low energy model scale, which are evoluted to the experimental momentum scale in terms of the Altarelli-Parisi equation. The resulting distribution functions show reasonable agreements with experiment. We also discuss the semi-inclusive lepton nucleon scattering process with a slow nucleon in coincidence in the final state, which reveals the off-shell structure of the pion.Comment: 31 pages with 16 figures as uuencoded postscript files, TMU-NT-940101 (plain LaTeX

Gene expression profile and pathogenicity of biofilm-forming Prevotella intermedia strain 17

<p>Abstract</p> <p>Background</p> <p><it>Prevotella intermedia </it>(<it>P. intermedia</it>), a gram-negative, black-pigmented anaerobic rod, has been implicated in the development of chronic oral infection. <it>P. intermedia </it>strain 17 was isolated from a chronic periodontitis lesion in our laboratory and described as a viscous material producing strain. The stock cultures of this strain still maintain the ability to produce large amounts of viscous materials in the spent culture media and form biofilm-like structures. Chemical analyses of this viscous material showed that they were mainly composed of neutral sugars with mannose constituting 83% of the polysaccharides. To examine the biological effect of the extracellular viscous materials, we identified and obtained a naturally-occurring variant strain that lacked the ability to produce viscous materials <it>in vitro </it>from our stock culture collections of strain 17, designated as 17-2. We compared these two strains (strains 17 versus 17-2) in terms of their capacities to form biofilms and to induce abscess formation in mice as an indication of their pathogenicity. Further, gene expression profiles between these two strains in planktonic condition and gene expression patterns of strain 17 in solid and liquid cultures were also compared using microarray assays.</p> <p>Results</p> <p>Strain 17 induced greater abscess formation in mice as compared to that of the variant. Strain 17, but not 17-2 showed an ability to interfere with the phagocytic activity of human neutrophils. Expression of several genes which including those for heat shock proteins (DnaJ, DnaK, ClpB, GroEL and GroES) were up-regulated two to four-fold with statistical significance in biofilm-forming strain 17 as compared to the variant strain 17-2. Strain 17 in solid culture condition exhibited more than eight-fold up-regulated expression levels of several genes which including those for levanase, extracytoplasmic function-subfamily sigma factor (σ^E; putative) and polysialic acid transport protein (KpsD), as compared to those of strain 17 in liquid culture media.</p> <p>Conclusion</p> <p>These results demonstrate that the capacity to form biofilm in <it>P. intermedia </it>contribute to their resistance against host innate defence responses.</p