Synthesis of 1-vinyl-3-ethylimidazolium-based ionic liquid (co)polymers by cobalt-mediated radical polymerizationDetrembleur, Christophe ; Debuigne, Antoine ; Hurtgen, Marie et alin Macromolecules (2011), 44(16), 6397-6404 The cobalt-mediated radical polymerization (CMRP) of 1-vinyl-3-ethylimidazolium bromide (VEtImBr) is described. Polymerizations were performed at 30 °C in solution either in dimethylformamide (DMF) or in ... [more ▼] The cobalt-mediated radical polymerization (CMRP) of 1-vinyl-3-ethylimidazolium bromide (VEtImBr) is described. Polymerizations were performed at 30 °C in solution either in dimethylformamide (DMF) or in methanol (MeOH) or in a mixture of both solvents, using a preformed alkyl–cobalt(III) adduct, CH3OC(CH3)2CH2–C(CH3)(CN)–(CH2–CHOAc)<4–Co(acac)2, as the mediating agent. Excellent control over molecular weights and dispersities (Mw/Mn 1.05–1.06) was achieved in MeOH, with a linear increase of experimental molecular weights with the monomer conversion. Substituting methanol for DMF induced much faster polymerization process, even under quite high diluted conditions: for instance, about 80% monomer conversion was reached in 30 min in DMF, compared to 10 h in MeOH. However, size exclusion chromatography (SEC) traces of PVEtImBr samples synthesized in DMF revealed a side population in the high molecular weight region, presumably due to the occurrence of irreversible coupling reactions of a small proportion of growing chains. Well-defined diblock copolymers featuring both a poly(vinyl acetate) (PVAc) block and a PVEtImBr-based poly(ionic liquid) block, PVAc-b-PVEtImBr, were next obtained by sequential CMRP of VAc and VEtImBr. To this end, a PVAc-Co(acac)2 was first prepared by CMRP and employed as a macroinitiator for the polymerization of VEtImBr either in methanol or in a mixture of DMF and MeOH (2/1: v/v) at 30 °C. Finally, cobalt-mediated radical coupling (CMRC) of the aforementioned PVAc-b-PVEtImBr diblock copolymers, using isoprene as a simple coupling agent, led to unprecedented and structurally well-defined PVAc-b-PVEtImBr-b-PVAc triblock copolymers. [less ▲] Detailed reference viewed: 56 (12 ULg) Synthesis of 2-amino-1,4-dihydro-4-quinolinones and diaminomethylene Meldrum’s acids derivatives as potential potassium channel openers; ; Pirotte, Bernard et alin Journal of Heterocyclic Chemistry (2002), 39 Detailed reference viewed: 14 (0 ULg) Synthesis of 2-aminoquinazoline-4(3H)-one derivatives as potential potassium channel openers; ; et al in Journal of Heterocyclic Chemistry (2000), 37 Detailed reference viewed: 18 (0 ULg) Synthesis of 2-Diethoxyphosphoryl-2-Methyl-5-Phenyl-3,4-Dihydro-2H-Pyrrole-1-Oxide (DEPMPO-Ph): a New Radical Spin-TrapOlive, Gilles ; ; et alin Symposium Drug Discovery Strategies: from Leads to Drugs (2001, November 16) The synthesis of a new radical spin trap is presented here: the 2-Diethoxyphosphoryl-2-Methyl-5-Phenyl-3,4-Dihydro-2H-Pyrrole-1-Oxide (DEPMPO-Ph) Detailed reference viewed: 6 (2 ULg) The synthesis of 6-[18F]fluoro-L-dopa by chiral catalytic phase-transfer alkylation.Lemaire, Christian ; ; Plenevaux, Alain et alin Journal of Labelled Compounds & Radiopharmaceuticals (1999), 42 Detailed reference viewed: 12 (1 ULg) Synthesis of 75Se-2-phenyl-1,2-benzisoselenazol-3-(2H)-one (PZ 51; EBSELEN*). A novel biologically active organo-selenium compound; ; Plenevaux, Alain et alin Journal of Labelled Compounds & Radiopharmaceuticals (1986), 23(1), 59-65 The preparation of 75Se-ebselen (75Se-PZ 51) in a high radiochemica] yield (~40 %) and with a specific act'ivity of 240 mCi/mM (8.9 GBq/mM) is described. Detailed reference viewed: 33 (1 ULg) Synthesis of [18F]4-(4-fluorophenyl)-1,2,4-triazole-3,5-dione: an agent for specific radiolabelling of tyrosine.Flagothier, Jessica ; Warnier, Corentin ; Lemaire, Christian et alin Flagothier, Jessica (Ed.) Journal of Labelled Compounds and Radiopharmaceuticals (2013, May 14) Objectives: Metal-free and mild tyrosine modification reactions are an attractive alternative to the commonly used lysine and cysteine modification protocols for peptide and proteins labelling. Recently ... [more ▼] Objectives: Metal-free and mild tyrosine modification reactions are an attractive alternative to the commonly used lysine and cysteine modification protocols for peptide and proteins labelling. Recently, Ban and co-workers have reported a tyrosine bioconjugation through ene-type reactions. Cyclic diazodicarboxamides, which are electrophilic compounds, react selectively in o-position on the phenol side chain of tyrosine in mild aqueous conditions and the 1,2,4-triazolidine-3,5-dione linkage is hydrolytically and thermally stable. We herein present the synthesis of [18F]4-(4-fluorophenyl)-1,2,4-triazole-3,5-dione and the coupling with N-acyl tyrosine methylamide. Methods: The N,N,N-trimethyl-4-nitrobenzeneammonium trifluoromethanesulfonate 1 was prepared following a procedure previously reported [2]. The [18F]prosthetic group 6, [18F]4-(4-fluorophenyl)-1,2,4-triazole-3,5-dione, was synthesized in five steps. Results: The synthesis of the [18F]prosthetic group has been realized with a decay-corrected radiochemical yield of 20% in 90 minutes. The radiochemical yield of the coupling with N-acyl tyrosine methylamide is 40% (DC). This presented synthetic pathway should be easily automated: particulary because the purifications between the different steps are exclusively done on SPE cartridges. Conclusions: We successfully developed an efficient bioconjugation method for fluorine-18 labelling of tyrosine without prior modifications of the peptide in very mild conditions. [less ▲] Detailed reference viewed: 1 (1 ULg) Synthesis of [18F]FDG with alkaline hydrolysis on a low polarity solid phase support.Lemaire, Christian ; ; Lauricella, Benjamino et alin Journal of Labelled Compounds & Radiopharmaceuticals (1997), 40 Detailed reference viewed: 15 (3 ULg) Synthesis of [18F]fluorinated a-methyl-a-amino acids by phase transfer catalysis for potential PET application.; Lemaire, Christian ; Plenevaux, Alain et alin Journal of Labelled Compounds & Radiopharmaceuticals (2003), 46 Detailed reference viewed: 4 (1 ULg) Synthesis of [Gamma-32p]Thiamine TriphosphateGrandfils, Christian ; Bettendorff, Lucien ; et alin Analytical Biochemistry (1988), 169(2), 274-278 We developed a novel chemical synthesis of thiamine triphosphate which allows us to incorporate 32P in the gamma position. The reaction is based on the condensation of [32P]orthophosphoric acid and ... [more ▼] We developed a novel chemical synthesis of thiamine triphosphate which allows us to incorporate 32P in the gamma position. The reaction is based on the condensation of [32P]orthophosphoric acid and thiamine diphosphate in the presence of ethyl chloroformate. After purification by two ion-exchange purification steps, the thiamine derivative has a specific radioactivity of 10 Ci/mmol. The average final yield synthesis is about 10%. [less ▲] Detailed reference viewed: 27 (4 ULg) Synthesis of a fluorinated analogue of L-threo-3-(3,4-dihydroxyphenyl)serine: 6-fluoro-L-threo-DOPS.; Lemaire, Christian ; Plenevaux, Alain et alin Journal of Labelled Compounds & Radiopharmaceuticals (1997), 40 Detailed reference viewed: 2 (1 ULg) Synthesis of a series of 4H-1,2,4-pyridothiadiazine 1,1-dioxides and their evaluation as new potassium channel openersDe Tullio, Pascal ; Pirotte, Bernard ; et alin Journal de Pharmacie de Belgique (1994), 49 Detailed reference viewed: 3 (1 ULg) Synthesis of a simplified bryostatin C-ring analogue that binds to the CRD2 of human PKC-alpha and construction of a novel BC-analogue by an unusual Julia olefination process; ; et al in Organic Letters (2003), 5(4), 499-502 [GRAPHICS] The synthesis of two truncated bryostatin analogues 2 and 3 is described. High-field NMR measurements on the C-ring analogue 3 in (CH3CN)-H-2 containing 25% (H2O)-H-2 have shown that it binds ... [more ▼] [GRAPHICS] The synthesis of two truncated bryostatin analogues 2 and 3 is described. High-field NMR measurements on the C-ring analogue 3 in (CH3CN)-H-2 containing 25% (H2O)-H-2 have shown that it binds to the CRD2 of human PKC-alpha at virtually the same position as phorbol-13-acetate (PA) and bryostatin 1 (1). NMR titration studies have also revealed that 3 binds to the CRD2 with a potency similar in magnitude to PA but much less potently than 1. [less ▲] Detailed reference viewed: 5 (1 ULg) Synthesis of acid-functional asymmetric aliphatic polyesters; ; Dubois, Philippe et alin Journal of Polymer Science Part A-Polymer Chemistry (1998), 36(8), 1345-1348 Detailed reference viewed: 14 (1 ULg) Synthesis of adherent hydrophilic polypyrrole coatings onto (semi)conducting surfacesGabriel, Sabine ; Cecius, Michaël ; Fleury-Frenette, Karl et alin Chemistry of Materials (2007), 19(9), 2364-2371 Hydrophilic and adherent polypyrrole coatings were prepared by a two-step electrochemical method. First, alpha-pyrrole, omega-acrylate polyethylene oxide (Py-PEO-A) dual macromonomer was synthesized by ... [more ▼] Hydrophilic and adherent polypyrrole coatings were prepared by a two-step electrochemical method. First, alpha-pyrrole, omega-acrylate polyethylene oxide (Py-PEO-A) dual macromonomer was synthesized by anionic polymerization and electrografted onto (semi)conducting substrates by cathodic polymerization of the acrylic end-group. The obtained adherent coating is hydrophilic and thus swells in water and bears a pyrrole ring, a precursor of the conducting polymer. In a second step, the coating is anodically polarized in a mixture of Py and Py-PEO to give the hydrophilic and adherent polypyrrole. Properties such as morphology, adherence, electroactivity, and hydrophilicity of these coatings were investigated by conventional methods and compared to those of pure polypyrrole coatings. These novel coatings exhibit efficient protein adsorption repellency and are thus good candidates for applications in biomaterials and biosensors. [less ▲] Detailed reference viewed: 70 (11 ULg) Synthesis of Ag/TiO2 hybrid photocatalysts by sol-gel process with new P-alkoxide functionalized ligandsLambert, Stéphanie ; ; et alPoster (2009) Detailed reference viewed: 44 (8 ULg) Synthesis of amonabactins by Aeromonas hydrophila : implication of NRPS of a unique iterate-alternative type; ; Wathelet, Bernard et alPoster (2011) Detailed reference viewed: 6 (0 ULg) Synthesis of amonabactins by Aeromonas hydrophila : implication of NRPS of a unique iterative-alternative type; ; Wathelet, Bernard et alPoster (2011) Detailed reference viewed: 14 (0 ULg) Synthesis of amphiphilic copolymers of poly(ethylene oxide) and poly(epsilon-caprolactone) with different architectures, and their role in the preparation of stealthy nanoparticlesRieger, Jutta ; ; et alin Advanced Functional Materials (2006), 16(11), 1506-1514 Well-defined copolymers of biocompatible poly(epsilon-caprolactone) (PCL) and poly(ethylene oxide) (PEO) are synthesized by two methods. Graft copolymers with a gradient structure are prepared by ring ... [more ▼] Well-defined copolymers of biocompatible poly(epsilon-caprolactone) (PCL) and poly(ethylene oxide) (PEO) are synthesized by two methods. Graft copolymers with a gradient structure are prepared by ring-opening copolymerization of epsilon-caprolactone (FCL) with a PEO macromonomer of the epsilon CL-type. The epsilon CL polymerization is initiated by a PEO macroinitiator to prepare diblock copolymers. These amphiphilic copolymers are used as stabilizers for biodegradable poly(DL-lactide) (PLA) nanoparticles prepared by a nanoprecipitation technique. The effect of the copolymer characteristic features (architecture, composition, and amount) on the nanoparticle formation and structure is investigated. The average size, size distribution, and stability of aqueous suspensions of the nanoparticles is measured by dynamic light scattering. For comparison, an amphiphilic random copolymer, poly(methyl methacrylate-co-methacrylic acid) (P(MMA-co-MA)), is synthesized. The stealthiness of the nanoparticles is analyzed in relation to the copolymer used as stabilizer. For this purpose, the activation of the complement system by nanoparticles is investigated in vitro using human serum. This activation is much less important whenever the nanoparticles are stabilized by a PEO-containing copolymer rather than by the P(MMA-co-MA) amphiphile. The graft copolymers with a gradient structure and the diblock copolymers with similar macromolecular characteristics (molecular weight and hydrophilicity) are compared on the basis of their capacity to coat PLA nanoparticles and to make them stealthy. [less ▲] Detailed reference viewed: 35 (10 ULg) |
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