636-70-4Relevant articles and documents
Palladium-Catalyzed Hydride Addition/C-H Bond Activation Cascade: Cycloisomerization of 1,6-Diynes
Rodríguez, José F.,Burton, Katherine I.,Franzoni, Ivan,Petrone, David A.,Scheipers, Ina,Lautens, Mark
supporting information, p. 6915 - 6919 (2018/11/21)
The use of ammonium halide salts as metal hydride precursors in a new Pd-catalyzed cycloisomerization of 1,6-diynes, which affords unexplored silylated 2-azafluorenes, is reported. This cascade process includes the addition of a Pd-hydride species to a π-system, intramolecular carbopalladation, and C(sp2)-H bond activation. A variety of functional groups are tolerated, and the synthetic utility of the resulting products has been demonstrated by a series of derivatizations.
A highly fluorescent cationic bifunctional conjugate
Yang,Chai,Zhu,Yang,Xu
experimental part, p. 7806 - 7812 (2012/08/13)
It was of crucial importance to modify perylene-3,4,9,10-tetracarboxylic acid bisimides (PBIs) for the design of new perylene-based bio-dye agents with strong fluorescence. Recently, we reported that ethanolamine (EA)-functionalized poly(glycidyl methacrylate) (or PGEA) can produce good transfection efficiency, while exhibiting very low toxicity. Herein, the low-toxic PGEA was proposed to be conjugated with PBIs via facile atom transfer radical polymerization for the well-defined highly fluorescent cationic bifunctional conjugate (PBI-PGEA). The obtained PBI-PGEA exhibited good water-solubility properties, characteristic spectroscopic patterns of PBIs, and excellent photostability. The PBI-PGEA conjugate can be used as an efficient cell bio-dye for rapid (2-5 min) cell labeling at low concentrations (0.06-0.12 mg mL-1). Such a fast labeling process did not induce obvious cytotoxicity, avoiding possible side-effects to the cells. In addition, the PBI-PGEA still possessed good gene transfection efficiency in different cell lines. With the strong fluorescence in water and good transfection properties, the developed bifunctional PBI-PGEA should possess more potential in bioimaging and gene delivery.
Preparation of biocompatible sterically stabilized latexes using well-defined poly(2-(methacryloyloxy)ethyl phosphorylcholine) macromonomers
Thompson, Kate L.,Bannister, Iveta,Armes, Steven P.,Lewis, Andrew L.
experimental part, p. 4693 - 4702 (2010/11/18)
A range of well-defined methacrylic macromonomers based on the biomimetic monomer 2-(methacryloyloxy)ethyl phosphorylcholine (MPC) were synthesized by atom-transfer radical polymerization (ATRP) in alcoholic media using 2-(dimethylamino)ethyl-2-bromoisobutyrylamide. This tertiary amine-functionalized initiator was used to produce homopolymer precursors of various chain lengths via ATRP. These polymerizations were relatively well controlled (Mw/Mn ≤ 1.30), provided that the target degree of polymerization (DP) did not exceed 30. For higher target DPs, polymerization was only poorly controlled and characterized by broad molecular weight distributions (Mw/Mn = 1.50-2.31). The tertiary amine end-group of each nearly monodisperse homopolymer precursor was then quaternized using 4-vinylbenzyl chloride (4-VBC) to afford the corresponding styrene-functionalized macromonomers. PMPC30 macromonomer proved to be an effective reactive steric stabilizer for the formation of polystyrene latexes when employed at 10 w/w % on the basis of the styrene monomer. Nearly monodisperse submicrometer-sized and micrometer-sized latexes were prepared by aqueous emulsion and alcoholic dispersion polymerization, respectively, as judged by scanning electron microscopy and dynamic light scattering studies. In contrast, attempted alcoholic dispersion polymerization conducted either in the presence of the PMPC30 homopolymer precursor or in the absence of any macromonomer always resulted in macroscopic precipitation. Such control experiments confirmed the importance of the terminal styrene groups on the macromonomer chains for successful latex formation. FTIR spectroscopy indicated the presence of the PMPC30 macromonomer within the polystyrene latex, and XPS studies indicated that these stabilizer chains are located at (or very near) the latex surface, as expected. Using PMPC20 and PMPC 10 macromonomers for the alcoholic dispersion polymerization of styrene led to latexes with substantially broader size distributions compared to those produced using the PMPC30 macromonomer under the same conditions. Finally, these new sterically stabilized latexes exhibit excellent freeze-thaw stability and salt tolerance.
