A highly effective one-pot synthesis of quinolines from o-nitroarylcarbaldehydes

A highly effective one-pot Friedl?nder quinoline synthesis using inexpensive reagents has been developed. o-Nitroarylcarbaldehydes were reduced to o-aminoarylcarbaldehydes with iron in the presence of catalytic HCl (aq.) and subsequently condensed in situ with aldehydes or ketones to form mono- or di-substituted quinolines in high yields (66-100%).     

Laminar flame speed and shock-tube multi-species laser absorption measurements of Dimethyl Carbonate oxidation and pyrolysis near 1 atm

Dimethyl Carbonate (DMC) is a carbonate ester that can be produced in an environment-friendly way from methanol and CO₂. DMC is one of the main components of the flammable electrolyte used in Li-ion batteries, and it can also be used as a diesel fuel additive. Studying the combustion chemistry of DMC can therefore improve the use of biofuels and help developing safer Li-ion batteries. The combustion chemistry of DMC has been investigated in a limited number of studies. The aim of this study was to complement the scarce data available for DMC combustion in the literature. Laminar flame speeds at 318 K, 363 K, and 463 K were measured for various equivalence ratios (ranging from 0.7 to 1.5) in a spherical vessel, greatly extending the range of conditions investigated. Shock tubes were used to measure time histories of CO and H₂O using tunable laser absorption for the first time for DMC. Characteristic reaction times were also measured through OH* emission. Shock-tube spectroscopic measurements were performed under dilute conditions, at three equivalence ratios (fuel-lean, stoichiometric, and fuel-rich) between 1260 and 1660 K near 1.3 ± 0.2 atm, and under pyrolysis conditions (98%+dilution) ranging from 1230 to 2500 K near 1.3 ± 0.2 atm. Laminar flame speed experiments were performed around atmospheric pressure. Detailed kinetics models from the literature were compared to the data, and it was found that none are capable of predicting the data over the entire range of conditions investigated. A numerical analysis was performed with the most accurate model, underlining the need to revisit at least 3 key reactions involving DMC.     

A novel mass spectrometry-based assay for GSK-3β activity

Background  

As a component of the progression from genomic to proteomic analysis, there is a need for accurate assessment of protein post-translational modifications such as phosphorylation. Traditional kinase assays rely heavily on the incorporation of γ-P³² radiolabeled isotopes, monoclonal anti-phospho-protein antibodies, or gel shift analysis of substrate proteins. In addition to the expensive and time consuming nature of these methods, the use of radio-ligands imposes restrictions based on the half-life of the radionucleotides and pose potential health risks to researchers. With the shortcomings of traditional assays in mind, the aim of this study was to develop a high throughput, non-radioactive kinase assay for screening Glycogen Synthase Kinase-3beta (GSK-3β) activity.     

On cluster kinetics and MBE growth

Based on the model of a so-called Near Surface Transition Layer (NSTL) proposed by HERMAN and ANDERSSON we discuss the possible role of clusters during MBE growth. Moreover, intentional use of small clusters instead of single atoms as beam constituents may contribute to improvements in crystal quality even at low substrate temperature and high growth rate.     

Regio- and stereoselective ring openings of 3-Aza-2-oxabicyclo[2.2.1]hept-5-ene systems with copper catalyst-modified grignard reagents: application to the synthesis of an inhibitor of 5-lipoxygenase

Treatment of acylnitroso hetero Diels-Alder cycloadducts 2 with organomagnesium reagents in the presence of a catalytic amount of copper induces ring opening to afford predominantly monocyclic anti-1,2-hydroxamic acids 12. Alkylmagnesium reagents were found to give superior regio- and stereoselectivities compared with vinyl and arylmagnesium reagents. This cycloadduct ring opening methodology was applied to the synthesis of a unique cyclopentenyl hydroxamic acid-based inhibitor of 5-lipoxygenase.     

Towards rapid throughput NMR studies of full wine bottles

A rapid throughput method for the quantitation of the oxidation level of intact full bottles of wine based on the 1331 water suppression pulse sequence is described. The ideal pulse sequence suppresses water in the (1)H nuclear magnetic resonance spectrum while uniformly and phase coherently exciting the resonances pertaining to ethyl alcohol at 1.1 ppm and oxidation products at 2.1 ppm. The anticipated results of the pulse sequence based on simulations are tested in small sample and full bottle standards and an application to the detection of wine spoilage in more than century old wine is provided.     

Synthesis of bifunctional polymer nanotubes from silicon nanowire templates via atom transfer radical polymerization

As a way to control the surface properties of nanowires and nanotubes, we present a method for growing polymer from the surface of silicon/silica core/shell nanowires. After modification of nanowire surfaces with polymer initiators, Atom Transfer Radical Polymerization (ATRP) was used to grow methacrylate polymer chains from the surface. The resulting structures were characterized by SEM, TEM, and EELS. After etching the silicon cores, the resulting polymer-coated nanotubes will have hydrophilic silica cores with hydrophobic polymer shells.