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A facile and practical silver-mediated radical cascade cyclization of N-allylamides with sodium sulfinates is developed, giving a series of sulfonated oxazolines in moderate to good yields. This transformation involves a radical process via intermolecular sulfonylation of alkenes and intramolecular cyclization. This reaction system could be also applied to access sulfonated dihydrofurans. [ABSTRACT FROM AUTHOR]

A novel peroxidase-mimicking DNAzyme-based colorimetric homogenous bioassay is developed for kanamycin detection. Aptamer biorecognition triggers DNAzyme liberation from DNA duplexes for “off–on” signal transduction. The special hairpin structure of the aptamer–kanamycin biocomposite enables Exo III-assisted target recycling for signal amplification. [ABSTRACT FROM AUTHOR]

Elaborate design of highly active catalysts from earth-abundant elements is important for the development of water-splitting devices. We have synthesized {2̅ 1 1} high index-faceted Ni12P5 nanoplates and Ni12P5 spherical nanoparticles (SNPs) by the one-step solvothermal method. The Ni12P5 nanoplates show enhanced hydrogen evolution reaction activity with a lower overpotential of −128 mV and a smaller Tafel slope of 60.6 mV dec−1 compared to Ni12P5 SNPs. Stability tests reveal exceptional durability of the catalyst. This study offers an attractive catalytic material for large-scale hydrogen production technology. [ABSTRACT FROM AUTHOR]

Silver nanosized particles were grown on the surface and in the channels of mesoporous silica (MCM-41) by stirring a mixture of AgNO3 and polyvinylpyrrolidone (PVP) in ethylene glycol in a 1 : 20 weight ratio with MCM-41 for 1 h. The heterogeneous product was analysed by BET surface area and X-ray powder diffraction measurements, as well as TEM images which indicated that 5 to 20 nm sized Ag particles were on the surface of MCM-41. The dried material, suspended in a mixture of 1,2-dichloroethane and acetonitrile and in the presence of tBuOOH held at 80 °C for 24 h, was capable of the oxidation of the olefins (Z)-cyclooctene, cyclohexene, styrene and indene resulting in a variety of oxidized products. Comparable oxidation was also accomplished in a green solvent mixture consisting of 3% NaCl dissolved in H2O and tBuOH (1 : 1 by volume). The catalyst was active for five sequential cycles. After the first cycle, H2O2 instead of tBuOOH could be used as the radical initiator as the Ag nanoparticles were passivated by the formation of AgCl on the surface. This research illustrates a method of oxygen activation allowing for the transfer of an oxygen atom from the atmosphere onto an olefin, presumably via the formation of a peroxide radical. [ABSTRACT FROM AUTHOR]