Synthesis of New Spiro[1,4,2-dioxazole-5,3′-indolin]-2′-one by 1,3-Dipolar Cycloaddition

Novel spiro[1,4,2-dioxazole-5,3′-indolin]-2′-one derivatives were synthesized by 1,3-dipolar cycloaddition reactions of the isatin derivative with aryl nitrile oxide. The cycloadducts were characterized by spectral data including ¹H NMR, ¹³C NMR, infrared, mass spectra, and elementary analysis.     

A method for generating nitrile oxides from nitroalkanes: a microwave assisted route for isoxazoles

A convenient route has been developed for generation of nitrile oxides in situ from nitroalkanes under very mild conditions using microwave irradiation, using 4-(4,6-dimethoxy[1,3,5]triazin-2-yl)-4-methylmorpholinium chloride (DMTMM) and DMAP as catalyst. Isoxazolines and isoxazoles are obtained in very good yields compared to known methods.     

Cycloaddition of Nitrile Oxides to Graphene: a Theoretical and Experimental Approach

Density functional theory (DFT) studies of the interaction between graphene sheets and nitrile oxides have proved the feasibility of the reaction through 1,3-dipolar cycloaddition. The viability of the approach has been also confirmed experimentally through the cycloaddition of few-layer exfoliated graphene and nitrile oxides containing functional organic groups with different electronic nature. The cycloaddition reaction has been successfully achieved in one-pot from the corresponding oximes under microwave (MW) irradiation. The successful formation of the isoxazoline ring has been confirmed by Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS).     

Cycloaddition of nitrones with arynes generated from benzobisoxadisilole or 2,3-naphthoxadisilole

1,3-Dipolar cycloaddition of nitrones with arynes generated in situ from benzobisoxadisilole or 2,3-naphthoxadisilole afforded the oxadisilole fused benzo[d]isoxazoline or the naphtho[2,3-d]isoxazoline derivatives at room temperature in good yields.     

Phosphonated Polyethylenimine‐Coated Nanoparticles: Size‐ and Zeta‐Potential‐Adjustable Nanomaterials

Novel partially phosphonated polyethylenimine polymers are developed in order to control the modification of nanoparticle (NP) surfaces. This polymer is built by an accessible one‐step process. The numerous phosphonate functions assume both a strong covalent anchoring on metal oxide NPs and a modulation of electric charges, while amino groups are associated with dispersion preservation and subsequent biofunctionalization. The zwitterionic nanomaterials obtained display a good stability toward pH and ionic strength. According to the selected percentage of phosphonation and the polymer size, zeta potential, and diameter of the particles are controlled.     

Prediction by 13C NMR of regioselectivity in 1,3‐dipolar cycloadditions of acridin‐9‐yl dipolarophiles

Strong correlation was found between ¹³C NMR chemical shifts of dipolarophilic CH?CH carbons and regioselectivity in 1,3‐dipolar cycloadditions of new acridin‐9‐yl dipolarophiles with stable benzonitrile oxides (BNO). Accordingly, two starting dipolarophiles, (acridin‐9‐yl)‐CH?CH‐R (R = COOCH₃ or Ph), reacted with three BNOs (2,4,6‐trimethoxy, 2,4,6‐trimethyl, and 2,6‐dichloro) to give a mixture of two target isoxazoline regioisomers in which the acridine was bound either to isoxazoline C‐4 carbon (4‐Acr) or C‐5 one (5‐Acr). Methyl 3‐(acridin‐9‐yl)propenoate afforded major 4‐(acridin‐9‐yl)‐isoxazoline‐5‐carboxylates (4‐Acr) and minor 5‐(acridin‐9‐yl)‐4‐carboxylates (5‐Acr). 9‐(2‐Styryl)acridine regiospecifically afforded only 4‐Acr cycloadducts. The ratios of regioisomers were compared with analogous reactions of acridin‐4‐yl dipolarophiles. Regioselectivity was dependent on a polarity of the CH?CH bond, donor effects in BNO, and stabilization by stacking of aromatic substituents in the products. Copyright © 2015 John Wiley & Sons, Ltd.     

Phosphonated oligoallylamine: Synthesis,characterization in water,and development of layer by layer assembly

The work focuses on the synthesis and layer by layer (LbL) assembly of oligoallylamine and phosphonated oligoallylamine. To this aim, the synthesis of oligoallylamine and the phosphonated form have been done by free radical polymerization in aqueous media. First, radical polymerization of acid salt of allylamine was performed. This charged polymer could not be characterized using classical analytical techniques such as size‐exclusion chromatography and matrix‐assisted laser desorption/ionisation‐time of flight mass spectroscopy due to presence of cations. This work demonstrated the interest of capillary electrophoresis (CE) to analyze charged oligomers, using very small amounts of samples. Entangled polymer solution CE was used as a size‐based separation technique for the characterization of the molar mass distribution using indirect ultraviolet detection and calibration based on vinyl pyridine standards. Phosphorus‐containing oligoallylamines having a number‐average molar mass of 1600 g mol^?1 and a 2.3 polydispersity index were obtained. When combined using the LbL approach, prepared polymers showed an exponential growth regime as demonstrated by Fourier transform infrared spectroscopy measurements. Furthermore, thermogravimetric analyses of the LbL‐assembled polymers showed an extraordinary thermal and thermo‐oxidative stability. © 2013 Wiley Periodicals, Inc. J Polym Sci Part B: Polym. Phys. 2013 , 51, 1244–1251     

An efficient process for synthesizing and hydrolyzing a phosphonated methacrylate: Investigation of the adhesive and anticorrosive properties

A new phosphonated methacrylate, namely dimethyl(methacryloyloxy)methyl phosphonate (MAPC₁), has been synthesized using paraformaldehyde and potassium carbonate according to the Pudovik reaction. The quantitative synthesis of MAPC₁ was followed by selective hydrolysis of the ester group with sodium bromide to replace NaI (imparting non‐negligible ecological impact). Pure MAPC₁(OH) was obtained in high yield and efficiently copolymerized with MMA. The r₁ for MAPC₁(OH)) and r₂ (for MMA) values are 0.99 and 1.02, respectively, which indicates that the monophosphonic groups are statistically linked to the methacrylate backbone. When blended with PVDF, MMA/MAPC₁(OH) copolymers show very good adhesion promoters in both dry and wet conditions and subsequently provide good anticorrosive properties. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4794–4803, 2008     

1,3-Cycloaddition of the nickel <Emphasis Type="Italic">meso</Emphasis>-cyanooctaethylporphyrin <Emphasis Type="Italic">N</Emphasis>-oxide complex to olefins. Molecular and crystal structure of a double cycloaddition product to 2,5-norbornadiene

Starting from the nickel meso-formyloctaethylporphyrin oxime complex, the meso-cyanooctaethylporphyrin N-oxide complex was synthesized for the first time. The new complex enters into 1,3-cycloaddition to olefins. The double addition of the nitrile oxide to 2,5-norbornadiene affords a porphyrin dimer, whose structure was established by X-ray diffraction analysis.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2098–2101, October, 2004.