14691-88-4Relevant articles and documents
Immobilization of catalysts in poly(p-xylylene) nanotubes
Hepperle, Johannes A.M.,Mitschang, Fabian,Bier, Anna K.,Dettlaff, Barbara K.,Greiner, Andreas,Studer, Armido
, p. 25976 - 25981 (2013)
This paper describes the immobilization of a TEMPO-derivative and a copper catalyst in ethinyl-functionalized poly(p-xylylene) nanotubes which are readily prepared by the Tubes by Fiber Templates (TUFT) process. Catalyst conjugation to the nanotubes is achieved via the Cu-catalyzed azide alkyne cycloaddition (CuAAC). The TEMPO-functionalized nanotubes are successfully used as recyclable catalysts for oxidation of benzyl alcohol. Recycling studies show that the TEMPO-modified nanotubes can be reused 20 times without loss of catalytic activity. Conjugation of the nanotubes with a bipyridine moiety provides a material that allows for immobilization of metal catalysts. Treatment with a Cu(i)-salt leads to a hybrid material, which shows high activity as a recyclable catalyst in the CuAAC. Recycling experiments reveal that these Cu-nanotubes can be reused for 18 runs.
NEW METHOD OF ELECTROCHEMICAL PREPARATION OF 1-OXYL-2,2,6,6-TETRAMETHYL-4-AMINOPIPERIDINE
Fioshin, M. Ya.,Avrutskaya, I. A.,Bogdanova, N. P.,Kedik, S. A.,Surov, I. I.
, p. 1541 (1983)
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Use of sodium cyanoborohydride in the preparation of biologically active nitroxides
Rosen
, p. 358 - 360 (1974)
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EPR Studies of V-ATPase with Spin-Labeled Inhibitors DCC and Archazolid: Interaction Dynamics with Proton Translocating Subunit c
G?lz, Jan Philipp,Bockelmann, Svenja,Mayer, Kerstin,Steinhoff, Heinz-Jürgen,Wieczorek, Helmut,Huss, Markus,Klare, Johann P.,Menche, Dirk
, p. 420 - 428 (2016)
Vacuolar-type H+-ATPases (V-ATPases) have gained recent attention as highly promising anticancer drug targets, and therefore detailed structural analyses and studies of inhibitor interactions are very important research objectives. Spin labeling of the V-ATPase holoenzyme from the tobacco hornworm Manduca sexta and V-ATPase in isolated yeast (Saccharomyces cerevisiae) vacuoles was accomplished by two novel methods involving the covalent binding of a (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) derivative of N,N′-dicyclohexylcarbodiimide (DCC) to the essential glutamate residue in the active site and the noncovalent interaction of a radical analogue of the highly potent inhibitor archazolid, a natural product from myxobacteria. Both complexes were evaluated in detail by electron paramagnetic resonance (EPR) spectroscopic studies and double electron-electron resonance (DEER) measurements, revealing insight into the inhibitor binding mode, dynamics, and stoichiometry as well as into the structure of the central functional subunit c of these medicinally important hetero-multimeric proton-translocating proteins. This study also demonstrates the usefulness of natural product derived spin labels as tools in medicinal chemistry. Near and DEER: Electron paramagnetic resonance (EPR) and double electron-electron resonance (DEER) studies of V-ATPase in complex with spin-labeled inhibitors DCC and archazolid have enabled insight into the noncovalent binding dynamics and analysis of the enzyme′s key functional subunit c. These studies also demonstrate the general utility of natural product derived spin labels as innovative tools for chemical biology.
THE OXIDATION OF SECONDARY AMINES BY ALKANESULFONIC PERACIDS
Safiullin, R. L.,Enikeeva, L. R.,Bukin, I. I.,Mukhametova, G. A.,Shishlov, N. M.,et al.
, p. 1045 - 1047 (1990)
Alkanesulfonic peracids are efficient oxidation agents for the conversion of secondary amines to the corresponding nitroxyl radicals.
Hierarchically structured, blue-emitting polymer hybrids through surface-initiated nitroxide-mediated polymerization and water templated assembly
Leone, Giuseppe,Giovanella, Umberto,Bertini, Fabio,Hoseinkhani, Sajjad,Porzio, William,Ricci, Giovanni,Botta, Chiara,Galeotti, Francesco
, p. 6585 - 6593 (2013)
A facile and robust approach for fabricating structured, blue-emitting polymer hybrids is explored by grafting poly(styrene) incorporating π-conjugated oligo(fluorene) side-chains, to fluoromica silicate layers through surface-initiated nitroxide-mediated polymerization (SI-NMP). It is expected that the polymer intercalation can effectively reduce π-stacking, chain-chain interactions, twists and bends, and interfacial effects, leading to significant difference in the electronic/optoelectronic properties, and improved optical, thermal and chemical stability of the materials. The experimental results indicate that the bottom-up strategy is rational and efficacious. The hybrids exhibit a blue photoluminescence quantum yield (PL-QY) as high as 0.90, even in the solid, which makes the materials appealing for polymer light-emitting devices (PLEDs). The materials also show significantly enhanced thermal, and chemical stabilities with respect to the organic precursors. If processed under specific controlled conditions, the hybrids spontaneously assemble into highly ordered microporous films, where an organization of matter at different length scales is obtained. Since the introduction of surface patterning in the active layer could enhance the extraction of light generated in the device, this hierarchical organization is a promising tool for the further development of optimized hybrid PLEDs.
A Simple Synthesis of 4-Amino-2,2,6,6-tetramethyl-1-piperidinyloxy Radical
Bushmakina, N. G.,Misharin, A. Yu.
, p. 966 (1986)
A simple synthesis of the title compound starting from 4-hydroxy-2,2,6,6-tetramethyl-1-piperidyloxy radical (2) based on sulfonate-azide exchange method is described.
Synthesis and fluorescence properties of six fluorescein-nitroxide radical hybrid-compounds
Sato, Shingo,Endo, Susumu,Kurokawa, Yusuke,Yamaguchi, Masaki,Nagai, Akio,Ito, Tomohiro,Ogata, Tateaki
, p. 66 - 71 (2016/07/06)
Six fluorescein-nitroxide radical hybrid-compounds (2ab, 3ab, 4, and 5) were synthesized by the condensation of 5- or 6-carboxy-fluorescein and 4-amino-TEMPO (2ab), 5- or 6-aminofluorescein and 4-carboxy-TEMPO (3ab), and fluorescein and 4-carboxy-TEMPO (4), or by reaction of the 3-hydroxyl group of fluorescein with DPROXYL-3-ylmethyl methanesulfonate (5). Fluorescence intensities (around 520 nm) after reduction of the radical increased to 1.43-, 1.38-, and 1.61-folds for 2a, 2b and 3b respectively; 3a alone exhibited a decrease in intensity on reduction. Since 4 was readily solvolyzed in PBS or even methanol to afford fluorescein and 4-carboxy-TEMPO, its fluorescence change could not be measured. Hybrid compound 5 containing an ether-linkage between the fluorescein phenol and 3-hydroxymethyl-DPROXYL hydroxyl centers, was stable and on reduction, showed a maximum increase (3.21-fold) in relative fluorescence intensity in PBS (pH 5.0), despite its remarkably low absolute fluorescence intensity.