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101.
Kawasaki I Tsunoda K Tsuji T Yamaguchi T Shibuta H Uchida N Yamashita M Ohta S 《Chemical communications (Cambridge, England)》2005,(16):2134-2136
A novel task-specific ionic ligand with an imidazolium salt moiety was synthesized, and its catalytic ability and recyclability for asymmetric transfer hydrogenation of acetophenone derivatives with a formic acid-triethylamine azeotropic mixture in an ionic liquid [bmim][PF6] was examined. 相似文献
102.
Ijima Y Matoishi K Terao Y Doi N Yanagawa H Ohta H 《Chemical communications (Cambridge, England)》2005,(7):877-879
The introduction of two mutations (G74C/C188S) based on the estimated reaction mechanism resulted in the inversion of enantioselectivity of arylmalonate decarboxylase, which catalyses the asymmetric decarboxylation of arylmethylmalonate to give optically active arylpropionate. 相似文献
103.
Masanao Oya Tomoko Takahashi Ryoichi Katakai 《Journal of polymer science. Part A, Polymer chemistry》1976,14(8):2065-2069
4-Isobutyloxazolidinedione, L -leucine N-carboxy anhydride, was polymerized to produce high molecular weight polymer with triethylamine in n-hexane which is not a solvent for the N-carboxy anhydride and poly-L -leucine. It was found that as the crystal size became smaller, the total surface area was increased, the initial rate of polymerization was increased, and inherent viscosity of the formed polymer was decreased. 相似文献
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108.
Hiromitsu Terao Yoshihiko Kai Kazuyo Kita Yoshihiro Furukawa 《Hyperfine Interactions》2010,198(1-3):93-101
The crystals of 4-NH2PyHSbI4 (Py = C5H4N) have been investigated by means of 127I NQR, 1H NMR T 1 and DTA. The crystals can exist in two modifications of β and α(I) at room temperatures. The α(I)-phase is a metastable state which is obtained when the stable β form is heated. The α(I)-phase undergoes a first-order type phase transition of α(I) $\leftrightarrow \alpha $ (II) at 272 K (on heating), while the β-phase is stable down to 77 K. Four and two 127I (m = ±1/2 $\leftrightarrow \pm $ 3/2) NQR lines have been found for the β- and α(II)-phases, respectively. One half of them is assignable to the terminal I atom(s) and the other to the bridging I atom(s) in each phase. All the resonance lines of the α(II)-phase underwent a disappearance above ca. 240 K and no resonance line was observed in the α(I)-phase. The second moment M 2 value of 1H NMR spectra with 8 G2 at 290 K shows that the 4-NH2PyH?+? cations reside in the rigid lattice in the β-phase. In contrast, in the α(I)-phase the cation rotates about an axis more symmetric than pseudo threefold axis. The activation energy of 21 kJ mol???1 was estimated for the reorientational motion in the α(I)-phase from the 1H NMR T 1 measurements. The nature of phase transitions in the 4-NH2PyHSbI4 is discussed in comparison with that in 4-NH2PyHSbBr4. 相似文献
109.
Summary: We developed a new method for synthesizing an organic-soluble permethylated cyclodextrin-based insulated molecular wire (IMW); this method involves the polymerization of a symmetrical linked inclusion complex as a monomer. This monomer was synthesized by dimerization of linked inclusion complexes at the terminal alkynyl groups by Glaser coupling. The polyrotaxane thus obtained is highly soluble in a variety of organic solvents and has a high covering ratio, regioregularity, and photoluminescence efficiency. 相似文献
110.
[Structure: see text] A Pd/C-catalyzed chemoselective hydrogenation using diphenylsulfide as a catalyst poison has been developed. This methodology selectively hydrogenates olefin and acetylene functionalities without hydrogenolysis of aromatic carbonyls and halogens, benzyl esters, and N-Cbz protective groups. 相似文献