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排序方式: 共有271条查询结果,搜索用时 15 毫秒
11.
Nicolas Zigon Manabu Hoshino Shota Yoshioka Yasuhide Inokuma Makoto Fujita 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(31):9161-9165
Crystal structures of α‐humulene, a cyclic sesquiterpene, and its oxidized subproducts, were analyzed by the crystalline sponge method. Regio‐ and stereochemistry, including absolute configuration when a chiral oxidant was applied, and the stable conformations of all the scaffold‐related compounds were successfully determined for samples on a 5–50 μg scale. 相似文献
12.
Katsuya Sako Toshiaki Kakehi Shota Nakano Hiroyuki Oku Xu Feng Shen Tetsuo Iwanaga Manami Yoshikawa Kouta Sugahara Shinji Toyota Hiroyuki Takemura Teruo Shinmyozu Michito Shiotsuka Hitoshi Tatemitsu 《Tetrahedron letters》2014
Two novel redox-active 1,3-dithiole (DT) ring-fused 4,5-diazafluorene ligands with crown ether moieties (L1 and L2) were synthesized and characterized. The crystal structure of L1 was studied. The electrochemical and spectroscopic properties of these new ligands, as well as the corresponding bis(bipyridine)ruthenium(II) complexes [4: Ru L1(bpy)2 and 5: Ru L2(bpy)2], were also been investigated. 相似文献
13.
Isamu Katsuyama Pandurang V. ChouthaiwaleHiroyuki Akama Hai-Lei CuiFujie Tanaka 《Tetrahedron letters》2014
Fluorogenic aldehydes or probes for monitoring of the progress of aldol reactions have been developed. Fluorescence of benzaldehydes conjugated with aryl groups via a double or triple bond and of their aldol products was evaluated in aqueous solutions. Based on the fluorescence, fluorogenic aldol reaction substrates and retro-aldol reaction substrates were identified. Use of the probe system with optimal fluorescence properties for aldol reactions was demonstrated in assays with purified protein catalysts and with overproduced crude protein catalysts in cell lysates. 相似文献
14.
Site‐Selective CH Borylation of Quinolines at the C8 Position Catalyzed by a Silica‐Supported Phosphane–Iridium System 下载免费PDF全文
Shota Konishi Dr. Soichiro Kawamorita Dr. Tomohiro Iwai Prof. Patrick G. Steel Prof. Dr. Todd B. Marder Prof. Dr. Masaya Sawamura 《化学:亚洲杂志》2014,9(2):434-438
Site‐selective C? H borylation of quinoline derivatives at the C8 position has been achieved by using a heterogeneous Ir catalyst system based on a silica‐supported cage‐type monophosphane ligand SMAP. The efficient synthesis of a corticotropin‐releasing factor1 (CRF1) receptor antagonist based on a late‐stage C? H borylation strategy demonstrates the utility of the C8 borylation reaction. 相似文献
15.
Sayoko Nagashima Shota Furukawa Satoshi Kamiguchi Ryu Kajio Hiroshi Nagashima Aritomo Yamaguchi Masayuki Shirai Hideki Kurokawa Teiji Chihara 《Journal of Cluster Science》2014,25(5):1203-1224
A series of molecular rhenium sulfide clusters [Re6S8(OH)6?n (H2O) n ](4?n)? (n = 0, 2, 4, 6) catalyze dehydrogenation of alcohols, and hydrogenation of ketones and olefins in a hydrogen stream at 350 °C. The catalytic activities of the dianionic and neutral clusters (n = 2, 4) are lower than those of tetraanionic and dicationic clusters (n = 0, 6) for all the reactions. When 1,4-butanediol is allowed to react over K4[Re6S8(OH)6], dehydrogenation proceeds to yield 2-hydroxytetrahydrofuran and successively γ-butyrolactone above 300 °C. Over [Re6S8(H2O)6]SO4 dehydration proceeds to yield tetrahydrofuran above 250 °C. The thermal activation mechanisms of these clusters were studied by powder X-ray diffraction analyses, Raman spectrometry, extended X-ray absorption fine structure spectrometry, thermogravimetry, and differential thermal analyses. The catalytically active site of K4[Re6S8(OH)6] is an uncoordinated metal site (Lewis acid site) developed by the loss of a water molecule from two hydroxo ligands. The active site of [Re6S8(H2O)6]SO4 is a Brønsted acid site; the anhydrous aqua cluster dication disproportionates to a hydroxo cluster monocation and a proton. Both of the octahedral cluster frameworks are retained up to 500 °C. 相似文献
16.
Yusuke Sasano Shota Nagasawa Mai Yamazaki Dr. Masatoshi Shibuya Prof. Dr. Jaiwook Park Prof. Dr. Yoshiharu Iwabuchi 《Angewandte Chemie (International ed. in English)》2014,53(12):3236-3240
The direct oxidation of unprotected amino alcohols to their corresponding amino carbonyl compounds has often posed serious challenges in organic synthesis and has constrained chemists to adopting an indirect route, such as a protection/deprotection strategy, to attain their goal. Described herein is a highly chemoselective aerobic oxidation of unprotected amino alcohols to their amino carbonyl compounds in which 2‐azaadamantane N‐oxyl (AZADO)/copper catalysis is used. The catalytic system developed leads to the alcohol‐selective oxidation of various unprotected amino alcohols, carrying a primary, secondary, or tertiary amino group, in good to high yield at ambient temperature with exposure to air, thus offering flexibility in the synthesis of nitrogen‐containing compounds. 相似文献
17.
An Isotope‐Coded Fluorogenic Cross‐Linker for High‐Performance Target Identification Based on Photoaffinity Labeling 下载免费PDF全文
Dr. Takenori Tomohiro Shota Morimoto Toshiya Shima Dr. Junya Chiba Dr. Yasumaru Hatanaka 《Angewandte Chemie (International ed. in English)》2014,53(49):13502-13505
A photoaffinity labeling (PAL)‐based method for the rapid identification of target proteins is presented in which a high‐performance chemical tag, an isotope‐coded fluorescent tag (IsoFT), can be attached to the interacting site by irradiation. Labeled peptides can be easily distinguished among numerous proteolytic digests by sequential detection with highly sensitive fluorescence spectroscopy and mass spectrometry. Subsequent MS/MS analysis provides amino acid sequence information with a higher depth of coverage. The combination of PAL and heterogeneous target‐selecting techniques significantly reduces the amount of time and protein required for identification. An additional photocleavable moiety successfully accelerated proteomic analysis using cell lysate. This method is a widely applicable approach for the rapid and accurate identification of interacting proteins. 相似文献
18.
Waro Nakanishi Satoko Hayashi Taro Nishide Shota Otsuki 《International journal of quantum chemistry》2020,120(4):e26073
A method to elucidate the dynamic and static natures of the activated interactions in transition states (TSs) is proposed using quantum theory of atoms-in-molecules (QTAIM) dual functional analysis (QTAIM-DFA). The natures are determined for the ligand exchange at the N of sulfonylimino-λ3-bromanes, RBr-*-N(SO2CF3)-*-X′R′ (R, R′ = Me or Ph, X′ = Br′ or I′). Asterisks (*) emphasize the presence of bond critical points within the interactions in question. While data from the optimized structures of TSs correspond to the static nature, those from the perturbed and optimized structures represent the dynamic nature. The nature of the interactions in Br-*-N-*-X′ calculated with QTAIM-DFA, using the perturbed structures generated using the normal coordinates for the imaginary frequencies (NIV), was very similar to that in trigonal bipyramidal adduct formation through charge transfer. The results with NIV were precisely the same as those obtained based on intrinsic reaction coordinate (IRC). The high applicability of QTAIM-DFA is demonstrated when analyzing the activated interactions in TSs. 相似文献
19.
Shota Ooi B. Adinarayana Daiki Shimizu Takayuki Tanaka Atsuhiro Osuka 《Angewandte Chemie (International ed. in English)》2020,59(24):9423-9427
While oxidation of 5,5′,15,15′‐tetramesityl‐10‐10′‐linked 3NH‐corrole dimer with DDQ gave the corresponding triply linked 2NH‐corrole tape, the use of an equimolar amount of p‐chloranil as a milder oxidant resulted in the formation of a 10‐10′‐linked neutral 2NH‐corrole radical dimer as a stable product. The stability of this peculiar product is ascribed largely to strong antiferromagnetic interaction of the two spins. Further oxidation of this diradical produced corrole tape, suggesting its involvement as a reaction intermediate to the corrole tape. Oxidation of 10‐10′‐linked bis‐pyridine‐coordinated CoIII corrole dimer with DDQ produced a cobalt corrole radical dimer and a doubly linked corrole dimer both as stable compounds bearing pyridine and cyanide axial ligands. This type of oxidative transformation involving neutral diradical intermediates is a unique reaction mechanism specific for corrole dimers. 相似文献