Nonsmooth Bundle Trust-region Algorithm with Applications to Robust Stability

We propose a bundle trust-region algorithm to minimize locally Lipschitz functions which are potentially nonsmooth and nonconvex. We prove global convergence of our method and show by way of an example that the classical convergence argument in trust-region methods based on the Cauchy point fails in the nonsmooth setting. Our method is tested experimentally on three problems in automatic control.     

Synthesis of 2,2'-arylmethylene bis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) in aqueous medium at room temperature

The reaction of dimedone with various aromatic aldehydes produces 2,2'-arylmethylene bis (3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) in excellent yields. The reactions occur in water as solvent at room temperature and avoiding the addition of any catalyst. The workup procedure is very simple and the products do not required further purification.     

Solid‐state synthesis of a new core–shell nanocomposite of polyaniline and silica via oxidation of aniline hydrochloride by FeCl3.6H2O

Among the different oxidants used for the preparation of polyaniline in the solid‐state, iron (III) chloride (FeCl₃.6H₂O) can act as both oxidant and dopant. This work reports the synthesis and characterization of novel composite of polyaniline/silica. The polymerization was performed by oxidative polymerization of aniline hydrochloride in the presence of silica and FeCl₃.6H₂O under solid‐state (solvent‐free) condition. The FeCl₃.6H₂O has been chemically supported on silica and generated silica‐supported FeCl₃ ( SSFe ), which plays three important roles simultaneously (a) oxidant, (b) primary dopant, and (c) secondary dopant (Lewis acid). Furthermore, the existence of silica is important for proceeding of polymerization in solid state. In the other words, the surface polymerization and green chemistry in solid state have been coupled. The characterization and doping process are verified by ultraviolet‐visible, Fourier transform infrared, atomic absorption spectroscopy, thermogravimetric analysis, differential scanning calorimetry, and elemental analysis (CHNS). From atomic absorption spectroscopy the ratio of Fe/N in the composite obtained about 1, which confirms the formation of delocalized polarons by SSFe in the composites. The conductivity is in the range of semi‐conductive. Furthermore, contact resistance was determined by circular‐transmission line measurement. According to scanning electron microscopy images silica particles have been thoroughly coated by polyaniline within the range of 0.2 to 1 µm. However, transition electron microscopy images depict the uniform solid nanospheres (no hollow spheres or fibers), and their mean diameters are under of 50 nm. It confirms nanocomposite of core–shell PANI‐SSFe. Copyright © 2016 John Wiley & Sons, Ltd.     

Composition and in vitro antibacterial activity of essential oils from four Satureja species growing in Iran

The composition and in?vitro antibacterial activity of essential oils from four Satureja species (S. bachtiarica, S. khuzistanica, S. mutica and S. rechingeri) growing in Iran were determined. According to the results of GC-FID and GC-MS analysis, all oil samples were principally composed of phenolic constituents (carvacrol and/or thymol) with the percentages ranging from 41.2% (S. bachtiarica) to 77.7% (S. rechingeri). Determining antibacterial activities by the disc diffusion method against two Gram-positive and two Gram-negative bacteria revealed the maximum activity against Bacillus cereus with a range of minimum inhibitory concentration values from 0.25 to 1?mg?mL(-1) and minimum bactericidal concentration values from 0.5 to 1?mg?mL(-1). The oils of S. khuzistanica and S. rechingeri appeared to be more active in general than those of other species. In conclusion, the essential oils of studied Satureja species have the potential to be considered as alternatives for synthetic food preservatives.     

Transformations of diphenylphosphinothioic acid tertiary amides mediated by directed ortho metallation

ortho-Lithiation of N,N-diisopropyl-P,P-diphenylphosphinothioic amide using n-BuLi in the presence of TMEDA in diethyl ether followed by electrophilic trapping is described as an efficient method for the synthesis of ortho-functionalised derivatives in high yields. The structural modification of the phosphinothioic amide includes C-X (X = P, S, Si, Sn, I) and C-C bond forming reactions with a large variety of electrophiles. Additional applications based on functional group transformations are also reported. They include imine formation, desulfurization and Suzuki cross-coupling reactions on selected compounds.     

Catalyst-free one-pot synthesis of a new class of 2H-furo[3,2-c]chromene-2,4(3H)-dione and arylamino-bis(coumarin)methane derivatives on water

A catalyst-free, environmentally benign, and simple procedure has been developed for the efficient synthesis of novel 2H-furo[3,2-c]chromene-2,4(3H)-dione and 3,3′-((arylamino)methylene)bis(4-hydroxycoumarin) derivatives from one-pot three-component condensation of 4-hydroxycoumarin, glyoxalic acid monohydrate and various amines in water under reflux condition. In this green synthetic protocol, the solvent water itself catalyzed the reaction via hydrogen bonding. One-pot, high yields, short reaction times, simple operation, environmental friendly and easy workup procedure are highlights. This is the first report for the synthesis of 2H-furo[3,2-c]chromene-2,4(3H)-dione and arylamino-bis(coumarin)methane derivatives.     

Ruthenium/dendrimer complex immobilized on silica-functionalized magnetite nanoparticles catalyzed oxidation of stilbenes to benzil derivatives at room temperature

A new ruthenium/dendrimer complex stabilized on the surface of silica-functionalized nano-magnetite was fabricated and well characterized. The nano-catalyst showed good activity in the synthesis of benzil derivatives via the oxidation of stilbenes with high turnover frequency (TOF) at room temperature. Moreover, the catalyst could also be reused up to fifteen times without any loss of its activity.     

Preparation of Silica Supported Tin Chloride: As a Recyclable Catalyst for the Silylation of Hydroxyl Groups with HMDS

Silica‐supported tin chloride [SiO₂‐Sn(Cl)_4‐n] has been prepared by mixing tin chloride with activated silica gel in toluene under refluxing conditions for one day. A range of primary, secondary, and tertiary alcohols as well as phenolic hydroxyl groups were converted into their corresponding trimethylsilyl ethers with hexamethyldisilazane in the presence of catalytic amounts of silica‐supported tin chloride at room temperature. An excellent chemoselective silylation of hydroxyl groups in the presence of other functional groups was also observed. This catalyst could be recycled and reused fifteen times without loss of efficiency.