Synthesis of fused heterocycles via preferential hydroamination of o-haloarylalkynes over N-arylation and successive intramolecular CC bond formation

A tandem approach for the synthesis of fused naphthyridines and isoquinolines via preferential regio- and stereoselective addition of indoles/pyrroles onto o-haloarylalkynes over N-arylation is described. Inexpensive hydroxymethyl benzotriazole has been used as ligand under microwave irradiation. The structure of the product was confirmed by the X-ray crystallographic studies.     

Isolation of the Copper Redox Steps in the Standard Selective Catalytic Reduction on Cu‐SSZ‐13

Operando X‐ray absorption experiments and density functional theory (DFT) calculations are reported that elucidate the role of copper redox chemistry in the selective catalytic reduction (SCR) of NO over Cu‐exchanged SSZ‐13. Catalysts prepared to contain only isolated, exchanged Cu^II ions evidence both Cu^II and Cu^I ions under standard SCR conditions at 473 K. Reactant cutoff experiments show that NO and NH₃ together are necessary for Cu^II reduction to Cu^I. DFT calculations show that NO‐assisted NH₃ dissociation is both energetically favorable and accounts for the observed Cu^II reduction. The calculations predict in situ generation of Brønsted sites proximal to Cu^I upon reduction, which we quantify in separate titration experiments. Both NO and O₂ are necessary for oxidation of Cu^I to Cu^II, which DFT suggests to occur by a NO₂ intermediate. Reaction of Cu‐bound NO₂ with proximal NH₄⁺ completes the catalytic cycle. N₂ is produced in both reduction and oxidation half‐cycles.     

Joint replenishment of multi retailer with variable replenishment cycle under VMI

In the recent article, Darwish and Odah (2010) develop a scheme that allows for identical replenishment cycles for all the retailers, in the context of a single vendor supplying a group of retailers under VMI partnership. This paper proposes an alternative replenishment scheme allowing for different replenishment cycles for each retailer. An example has been shown to illustrate the cost savings under the proposed model.     

Representation of integers by a family of cubic forms

Under certain conditions on the coefficients, we derive asymptotic formulas for the number of representations of zero and of large positive integers by the cubic forms that can be written as $L_{1}(x_{1},x_{2},x_{3}) Q_{1}(x_{1},x_{2},x_{3})+ L_{2}(x_{4},x_{5},x_{6}) Q_{2}(x_{4},x_{5}, x_{6}) + a_{7} x_{7}^{3}$ , where L ₁ and L ₂ are linear forms, Q ₁ and Q ₂ are quadratic forms, and a ₇ is a nonzero integer.     

Proteome and phosphoproteome of primary cultured pig urothelial cells

Epithelial tissue lining the inner side of the urinary bladder is the most common target for bladder cancer-related diseases. Bladders of freshly slaughtered pigs were utilised for a comprehensive analysis of the proteome and phosphoproteome of bladder epithelial cells. Following protein separation by 2-D gel electrophoresis and identification by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF-MS) the first proteome and phosphoproteome maps of pig urinary bladder epithelial cells (PUBEC) were established. A total of 120 selected protein spots were identified. By using the La(3+) enrichment method further developed in our laboratory we identified 31 phosphoproteins with minimal contamination by non-phosphopeptides. The 2-DE map of pig urothelial cells may prove as a useful tool for studies on uroepithelial biology, and the analysed phosphoproteins expression pattern, together with the whole cell proteome, will be helpful for identifying the proteins involved in bladder-related diseases.     

A Novel Ternary Graphene‐based Nanocomposite Modified Electrode for Acetaminophen Detection

Herein, design and synthesis of ternary gold nanoparticles@ sulfourea‐functionalized reduced graphene oxide (Gold‐NPs@SFG) is reported. It involves interaction of ‘sulfourea’ to the graphene sheets via amidation of edged carboxyls of graphene oxide with N‐terminals of sulfourea followed by association of Gold‐NPs. Sulfourea not only reduced the graphene oxide but interestingly, it is functionalized to graphene sheets via carbodiimide covalent junctions, which gives it local effect to increase the active surface area and excellent electrocatalytic properties. The prepared nanocomposite was characterized with SEM, TEM, FTIR, Raman, XRD, XPS and CV. Gold‐NPs@SFG was found to be more efficient electrocatalyst for the electrocatalytic oxidation of a drug ‘Acetaminophen’ using differential pulse voltammetry and it was employed as a highly sensitive and selective electrochemical sensor for the quantification of ‘Acetaminophen’ with the detection limit of 0.09 μM in the wide linear range of 1.2 to 300 μM.     

An expeditious protocol for sesquiterpene-cored functionalized arenes from S-(−)-citronellal

An expeditious straightforward synthesis of sesquiterpene-cored arenes functionalized with electron-withdrawing or electron-donating substituents is described and illustrated by Michael addition of S-(−)-citronellal on functionalized 2H-pyran-2-one in a single step at room temperature. The reaction was further generalized by synthesizing isoprenylated 9,10-dihydrophenanthrene-2-carbonitrile using 5,6-dihydro-2-oxo-4-sec-amino-2H-benzo[h]chromene-3-carbonitriles and S-(−)-citronellal under similar reaction conditions.     

The chemistry of pyridine thiols and related ligands,Part 6. The crystal and molecular structure of [1,3–bis(diphenylphosphino)-propane][bis(pyridine-2–thiolato)]ruthenium(II). A comparison with solution phase behaviour

Reaction of cis-RuCl2(dppp)2 with pyridine-2–thiol (HpyS) in the presence of Et3N in dry benzene replaces both the chloro groups and a diphosphine molecule to form Ru(dppp)(pyS)2 (1) [dppp=Ph2P(CH2)3PPh2], whose crystal and molecular structure has been determined with the help of single crystal X-ray crystallography. The discrete molecules of (1) adopt a distorted octahedral structure containing chelating pyridine-2–thiolato and dppp ligands with trans-S, cis-N and cis-P atom dispositions. The important interatomic parameters are: Ru-S, 2.443(2), 2.339(2); Ru-N, 2.133(5), 2.129(5); Ru-P, 2.274(2), 2.279(2)Å; trans-bond angles, S-Ru-S, 153.89(6); N-Ru-P, 172.76(13), 163.51(14)°; bite angles: P-Ru-P, 90.71(6); N-Ru-S, 67.18(14), 67.72(14)°. The n.m.r. spectra (1H, 13C, 31P) of (1) are also reported in order to compare solution phase behaviour with the solid state structure. The 13C-n.m.r. spectrum of the complex shows the presence of non-equivalent phenyls in the Ph2P-moiety.     

Local shell-to-shell energy transfer via nonlocal interactions in fluid turbulence

In this paper we analytically compute the strength of nonlinear interactions in a triad, and the energy exchanges between wave-number shells in incompressible fluid turbulence. The computation has been done using first-order perturbative field theory. In three dimensions, magnitude of triad interactions is large for nonlocal triads, and small for local triads. However, the shell-to-shell energy transfer rate is found to be local and forward. This result is due to the fact that the nonlocal triads occupy much less Fourier space volume than the local ones. The analytical results on three-dimensional shell-to-shell energy transfer match with their numerical counterparts. In two-dimensional turbulence, the energy transfer rates to the nearby shells are forward, but to the distant shells are backward; the cumulative effect is an inverse cascade of energy.