180397-75-5Relevant academic research and scientific papers
Directed one-pot syntheses of crown ether wheel-containing main chain-type polyrotaxanes with controlled rotaxanation ratios
Nakazono, Kazuko,Ishino, Tomonori,Takashima, Tomoyuki,Saeki, Daisaku,Natsui, Daisuke,Kihara, Nobuhiro,Takata, Toshikazu
, p. 15341 - 15344 (2014)
The directed synthesis of main chain-type polyrotaxanes possessing crown ether wheels was successfully achieved through two methods, A and B. Method A involved the direct wheel threading of poly(sec-ammonium salt) followed by end-capping with a bulky group, while method B utilized polyaddition of a pseudo[2]rotaxane monomer to facilitate the control of the structure, i.e. the rotaxanation ratio.
Selective Acceptorless Dehydrogenation of Primary Amines to Imines by Core–Shell Cobalt Nanoparticles
Cui, Xinjiang,Li, Wu,Junge, Kathrin,Fei, Zhaofu,Beller, Matthias,Dyson, Paul J.
, p. 7501 - 7507 (2020)
Core–shell nanocatalysts are attractive due to their versatility and stability. Here, we describe cobalt nanoparticles encapsulated within graphitic shells prepared via the pyrolysis of a cationic poly-ionic liquid (PIL) with a cobalt(II) chloride anion. The resulting material has a core–shell structure that displays excellent activity and selectivity in the self-dehydrogenation and hetero-dehydrogenation of primary amines to their corresponding imines. Furthermore, the catalyst exhibits excellent activity in the synthesis of secondary imines from substrates with various reducible functional groups (C=C, C≡C and C≡N) and amino acid derivatives.
Switchable activity of a Ru catalyst bearing an annulated mesoionic carbene ligand for oxidation of primary amines
Bera, Jitendra K.,Din Reshi, Noor U,Pal, Nilay Kumar,Pal, Saikat,Pal, Sourav,Yadav, Suman
, (2022/01/31)
The catalytic activity of a Ru complex 1, bearing a fused π-conjugated imidazo[1,2–a][1,8]naphthyridine-based mesoionic carbene (MIC) ligand, is examined for the oxidation of primary amines. Complex 1 affords nitrile or imine depending on the nature of th
Confined pyrolysis of a dye pollutant for two-dimensional F,N,S tri-doped nanocarbon as a high performance oxidative coupling reaction catalyst
Chen, Sian,Hu, Yajing,Li, Fang-Fang,Liu, Sijie,Peng, Ping,Wang, Haining,Yu, Ao,Yu, Bingzhe
, p. 7839 - 7847 (2020/11/30)
Nanocarbon materials as metal-free catalysts for the oxidative coupling of primary amines to imines suffer from high catalyst loading, low reaction rate and high oxygen demand. Doping heteroatoms in nanocarbons is realized as an effective strategy to improve the catalytic activity, however, the doping of fluorine has been rarely studied. Here we synthesized a F,N,S tri-doped hierarchical nanocarbon (FNSHC) by pyrolyzing a fluorine-containing azo-sulphonate dye (acid red-337, a pollutant in wastewater) confined in a layered double hydroxide (LDH). The LDH-confined synthetic method is beneficial to the formation of a two-dimensional porous structure with a large specific surface area (～1432 m2 g-1) and high fluorine content, enabling remarkable catalytic performance (98% yield in 4 h at 2 wt% catalyst loading under open-air conditions) and high recyclability, outcompeting current metal-free carbocatalysts. The conversion of environmental pollutants into heteroatom-doped carbon materials provides a new green strategy for the design and synthesis of functional carbon catalysts.
Nitrogen-Doped Carbon-Supported Nickel Nanoparticles: A Robust Catalyst to Bridge the Hydrogenation of Nitriles and the Reductive Amination of Carbonyl Compounds for the Synthesis of Primary Amines
Zhang, Yangmin,Yang, Hanmin,Chi, Quan,Zhang, Zehui
, p. 1246 - 1255 (2019/03/07)
An efficient method was developed for the synthesis of primary amines either from the hydrogenation of nitriles or reductive amination of carbonyl compounds. The reactions were catalyzed by nitrogen-doped mesoporous carbon (MC)-supported nickel nanoparticles (abbreviated as MC/Ni). The MC/Ni catalyst demonstrated high catalytic activity for the hydrogenation of nitriles into primary amines in high yields (81.9–99 %) under mild reaction conditions (80 °C and 2.5 bar H2). The MC/Ni catalyst also promoted the reductive amination of carbonyl compounds for the synthesis of primary amines at 80 °C and 1 bar H2. The hydrogenation of nitriles and the reductive amination proceeded through the same intermediates for the generation of the primary amines. To the best of our knowledge, no other heterogeneous non-noble metal catalysts have been reported for the synthesis of primary amines under mild conditions, both from the hydrogenation of nitriles and reductive amination.
Ligand controlled switchable selectivity in ruthenium catalyzed aerobic oxidation of primary amines
Ray, Ritwika,Chandra, Shubhadeep,Yadav, Vishal,Mondal, Prasenjit,Maiti, Debabrata,Lahiri, Goutam Kumar
supporting information, p. 4006 - 4009 (2017/04/11)
A ligand controlled catalytic system for the aerobic oxidation of 1° amines to nitriles and imines has been developed where the varying π-acidic feature of BIAN versus phen in the frameworks of ruthenium catalysts facilitates switchable selectivity.
Combining different hydrogen-bonding motifs to self-assemble interwoven superstructures
Ashton, Peter R.,Fyfe, Matthew C. T.,Hickingbottom, Sarah K.,Menzer, Stephan,Stoddart, J. Fraser,White, Andrew J. P.,Williams, David J.
, p. 577 - 589 (2007/10/03)
A series of carboxyl-substituted dibenzylammonium salts have been cocrystallized with the macrocyclic polyethers dibenzo[24]crown-8 (DB24C8) and bis-p-phenylene[34]crown-10 (BPP34C10) to effect the noncovalent syntheses of a wide range of interwoven superstructures in the solid state. In all cases, the dibenzylammonium cations thread through the cavities of the macrocyclic polyethers - primarily as a result of N+-H ··· O hydrogen bonds, with occasional secondary stabilization from C - H ··· O and aryl-aryl interactions - to form pseudorotaxane complexes possessing supplementary recognition sites (specifically, carboxyl groups) for further intercomplex association through hydrogen bonding. One unit of each of the dibenzylammonium cations threads through the DB24C8 macrocycle to make single-stranded, carboxyl-containing [2]pseudorotaxanes that interact further with one another to produce novel supramolecular architectures as a result of hydrogen bonding between their carboxyl groups (the carboxyl dimer supramolecular synthon), or between carboxyl groups and polyether oxygen atoms. Elaborate architectures, such as side-/main-chain pseudopolyrotaxanes and a daisy-chain-like supramolecular array, were thus synthesized noncovalently. BPP34C10 can accommodate two cations within its macrocyclic interior to form carboxyl-containing [3]pseudorotaxanes in which BPP34C10 acts as a girdle that helps to control the spatial orientation of the carboxylic acid-containing recognition sites for additional intersupramolecular association through the carboxyl dimer. PF6/- anions were also found to play a role in the self-assembly processes. When the anions interact with the [3]pseudorotaxanes, these recognition sites are oriented in the same direction. This leads to the formation of doubly-encircled multicomponent supermolecules when BPP34C10 is cocrystallized with dibenzylammonium cations bearing only one carboxyl substituent. On the other hand, when BPP34C10 is cocrystallized with an isophthalic acid-substituted ammonium cation, there is no evidence of any anion assistance to self-assembly; the isophthalic acid units are aligned in opposite directions, creating an interwoven supramolecular cross-linked polymer.
Self-Assembling - and Rotaxanes from Secondary Dialkylammonium Salts and Crown Ethers
Ashton, Peter R.,Glink, Peter T.,Stoddart, J. Fraser,Tasker, Peter A.,White, Andrew J. P.,Williams, David J.
, p. 729 - 736 (2007/10/03)
The self-assembly of three new rotaxanes - two rotaxanes and a rotaxane - formed by a "threading followed by stoppering" approach is described.These template-directed syntheses rely on the formation of pseudorotaxane intermediates, which self-assemble in solution from functionalized secondary dialkylammonium hexafluorophosphate threads and macrocyclic polyether rings (either dibenzocrown-8 or its asymmetric constitutional isomer).The stoppers - substituted 1,2,3-triazoles - were created by thermally allowed 1,3-dipolar cycloaddition between azido groups, which terminate the threads, and di-tert-butyl acetylenedicarboxylate. - Keywords: interlocking molecules; molecular recognition; pseudorotaxanes; rotaxanes; template syntheses
