- NEW C-C BOND FORMATION WITH PYRIDINIUM METHYLIDE: HYDROMETHYLENATION OF OLEFIN
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New C-C bond formation with pyridinium methylide is presented: Pyridinium methylide reacts with electron-deficient olefins providing the next higher homologs of olefins, in which the double bond of starting olefin is saturated and, instead, a C=C double bond is newly formed.This reaction mode has been never reported before in the study of nitrogen ylide and is to be referred to as hydromethylenation of olefin.In the presence of base, 1,2-double bond migration occurs leading to the methylated derivatives of starting olefins.
- Tsuge, Otohiko,Kanemasa, Shuji,Kuraoka, Satoru,Takenaka, Shigeori
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- Design and preparation of bio-based dielectric elastomer with polar and plasticized side chains
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A new dielectric elastomer with large actuated strain driven by low electric field was synthesized from di-n-butyl itaconate and isoprene through free radical redox emulsion polymerization. The effect of the copolymerized proportion of poly(di-n-butyl itaconate-co-isoprene) (PDBII) and the dosage of crosslinking agent on the elastic modulus, dielectric properties, and actuated strain of the elastomer were investigated, and a potential dielectric elastomer candidate containing 70 wt% di-n-butyl itaconate was obtained. The permittivity of the PDBII crosslinked by 3.0 phr of dicumyl peroxide was 5.68 at 103 Hz, which was higher than that of commercial acrylic and silicone dielectric elastomers. Without any prestrain, an actuated strain of 20% was obtained at an electric field of 30 kV mm-1. In order to further increase the actuated strain, barium titanate (BaTiO3), a high-dielectric-constant ceramic powder, was utilized to fill the PDBII to form a BaTiO3/PDBII composite. The dielectric constant of the composite increased with increasing content of BaTiO3, and the elastic modulus of the composite was lower than that of the unfilled PDBII, leading to a larger dielectric actuated strain of the composite.
- Lei, Weiwei,Wang, Runguo,Yang, Dan,Hou, Guanyi,Zhou, Xinxin,Qiao, He,Wang, Wencai,Tian, Ming,Zhang, Liqun
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- Highly chemoselective esterification for the synthesis of monobutyl itaconate catalyzed by hierarchical porous zeolites
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Monobutyl itaconate (MBI) are commercially prepared by using freshly distilled acetyl chloride as catalysts, which, however, always results in complicated purification processes due to the usage of water-carrying agents. Here, we report the highly selecti
- Zhu, Yan,Hua, Zile,Song, Yudian,Wu, Wei,Zhou, Xiaoxia,Zhou, Jian,Shi, Jianlin
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- Renewable biobased polymeric materials: Facile synthesis of itaconic anhydride-based copolymers with poly(l -lactic acid) grafts
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This paper reports a new synthesis of biobased polymers by using itaconic anhydride (IAn) and lactic acid (LA) as renewable starting materials. Poly(lactic acid) (PLA)-graft copolymers were synthesized via two approaches. First, the macromonomer approach utilized IAn for Sn-catalyzed synthesis of PLA-containing macromonomers (IAn-PLA Macro). The macromonomer was radically copolymerized with n-butyl methacrylate (BMA), n-butyl acrylate (BA), methyl methacrylate (MMA), and ethyl methacrylate (EMA) to give efficiently graft copolymers (PLA-Graft copolymer (I)) with molecular weight Mn up to 1.61 × 105 having biomass content higher than 34 wt %. Second, the copolymer approach employed first IAn as comonomer for radical copolymerization with BMA, giving rise to IAn-BMA copolymer with Mn higher than 5.76 ×104. Then, Sn-catalyzed grafting of PLA onto IAn moiety of the copolymer produced PLA-Graft copolymer (II) with Mn higher than 5.88 × 104, showing biomass content ≥29 wt %. In addition, radical homopolymerization of IAn was examined to give polyIAn. By using these two approaches employing IAn as a starting reactive material, PLA-graft copolymers were obtained as biomass-plastics. Properties of PLA-Graft copolymers (I) were also examined, which revealed possible applications for coatings and plastics. Furthermore, the IAn-containing graft copolymers will be a convenient starting biomass polymer having reactive IAn moiety in the main chain for further grafting or various functional group-introducing reactions.
- Okuda, Tomoya,Ishimoto, Kiyoaki,Ohara, Hitomi,Kobayashi, Shiro
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- Method for efficiently and environmentally friendly preparing dibutyl itaconate on basis of heterogeneous catalysis
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The invention discloses a method for efficiently preparing dibutyl itaconate on the basis of heterogeneous catalysis. Particularly, an efficient solid acid catalyst is adopted, itaconic acid and n-butanol are catalyzed heterogeneously to react without a water-carrying agent to generate the dibutyl itaconate under the conditions that the reaction temperature is 100-140 DEG C and the reaction time is 2-5 hours; and the solid acid catalyst hydrogenated macroporous strong acid type cation exchange resin. Compared with a traditional proton acid catalysis method, the method has the characteristics that 1, the catalytic efficiency is high, the reaction time is short, and the energy consumption is low; 2, heterogeneous catalysis is carried out, a reaction product and a catalyst are easily separated, and aftertreatment is simple; 3, esterification reaction are gentle, and side reactions are less; and 4, after the catalyst is separated, the repeated utilization rate of the catalyst is high.
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Paragraph 0031-0042
(2019/04/06)
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- Synthesis and Bioactivity of Polymer-Based Synthetic Mimics of Antimicrobial Peptides (SMAMPs) Made from Asymmetrically Disubstituted Itaconates
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A series of asymmetrically disubstituted diitaconate monomers is presented. Starting from itaconic anhydride, functional groups could be placed selectively at the two nonequivalent carbonyl groups. By using 2D NMR spectroscopy, it was shown that the first functionalization step occurred at the carbonyl group in the β position to the double bond. These monomers were copolymerized with N,N-dimethylacrylamide (DMAA) to yield polymer-based synthetic mimics of antimicrobial peptides (SMAMPs). They were obtained by free radical polymerization, a metal-free process, and still maintained facial amphiphilicity at the repeat unit level. This eliminates the need for laborious metal removal and is advantageous from a regulatory and product safety perspective. The poly(diitaconate-co-DMAA) copolymers obtained were statistical to alternating, and the monomer feed ratio roughly matched that of the repeat unit content of the copolymers. Investigations of varied R group hydrophobicity, repeat unit ratio, and molecular mass on antimicrobial activity against Escherichia coli and on compatibility with human keratinocytes showed that the polymers with the longest R groups and lowest DMAA content were the most antimicrobial and hemolytic. This is in agreement with the biological activity of previously reported SMAMPs. Thus, the design concept of facial amphiphilicity has successfully been transferred, but the selectivity of these polymers for bacteria over mammalian cells still needs to be optimized.
- Boschert, David,Schneider-Chaabane, Alexandra,Himmelsbach, Andreas,Eickenscheidt, Alice,Lienkamp, Karen
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p. 8217 - 8227
(2018/05/30)
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- Esterification of itaconic acid using Ln~SO4 2-/TiO2-SiO2 (Ln = La3+, Ce 4+, Sm3+) as catalysts
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A series of itaconate esters, e.g. dimethyl itaconate, dibutyl itaconate and diisooctyl itaconate, were synthesized using solid acid SO4 2-/MxOy (M = Ti4+, Fe3+, Zr4+, Al3+) and SO42-/TiO2-SiO2 modified with lanthanide ion (Ln = La3+, Ce4+, Sm 3+) as catalysts. It was found that SO4 2-/TiO2-SiO2 modified with lanthanide ion were of the same excellent catalytic activity as sulfuric acid (H2SO 4). Moreover, Ln~SO42-/TiO 2-SiO2 is of excellent stability. Take La 3+~SO42-/TiO2-SiO2 for example, the influence of the preparation conditions on catalytic performance was in detail examined by Py-FTIR, NH3-FTIR, XRD and NH3-TPD, and the optimum preparation conditions were obtained. Furthermore, the effective separation of product combined with the recyclable catalyst is expected to contribute to the development of clean and environmental friendly strategy for the synthesis of itaconate esters.
- Li, Lu,Liu, Shiwei,Xu, Junming,Yu, Shitao,Liu, Fusheng,Xie, Congxia,Ge, Xiaoping,Ren, Jianyun
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- ELECTROOXIDATIVE DESULFENYLATION OF MICHAEL-TYPE THIOL ADDUCTS OF α,β-UNSATURATED ESTERS, KETONES, AND NITRILES
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Michael adducts of ethanethiol with α,β-unsaturated esters ketones,and nitriles are conveniently desulfenylated under neutral conditions by an electrooxidation involving bromonium ion mediation.
- Kimura, Makoto,Matsubara, Shinichi,Sawaki, Yasuhiko,Iwamura, Hiizu
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p. 4177 - 4178
(2007/10/02)
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