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201.
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Dr. Yuki Sakamoto Dr. Toru Amaya Dr. Takeyuki Suzuki Prof. Dr. Toshikazu Hirao 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(52):18686-18689
The PdII‐catalyzed dehydroboration of boron enolates generated from ketones and 9‐iodo‐9‐borabicyclo[3.3.1]nonane was achieved, providing a synthetically versatile protocol from ketones to α,β‐unsaturated ketones. The PdII compound employed in this reaction worked catalytically in the presence of Cu(OAc)2. The high trans‐selectivity of the olefinic moiety was observed. Aryl halide moieties (‐Br and ‐Cl) remained intact for this reaction in spite of the presence of a Pd species. An ester substrate could also be applied when a stoichiometric amount of PdII was used. The crossover reactions using boron and silyl enolates revealed that the oxidation reaction is much faster than the Saegusa‐Ito reaction. 相似文献
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Yuki Kanazawa Prof. Hayato Tsuji Prof. Masahiro Ehara Prof. Ryoichi Fukuda Dr. Deborah L. Casher Prof. Kohei Tamao Prof. Hiroshi Nakatsuji Prof. Josef Michl 《Chemphyschem》2016,17(19):3010-3022
The photophysical properties of oligosilanes show unique conformational dependence due to σ‐electron delocalization. The excited states of the SAS, AAS, and AEA conformations of peralkylated n‐hexasilanes, in which the SiSiSiSi dihedral angles are controlled into a syn (S), anti (A), or eclipsed (E) conformation, were investigated by using UV absorption, magnetic circular dichroism (MCD), and linear dichroism spectroscopy. Simultaneous Gaussian fitting of all three spectra identified a minimal set of transitions and the wavenumbers, oscillator strengths, and MCD B terms in all three compounds. The results compare well with those obtained by using the symmetry‐adapted‐cluster configuration interaction method and almost as well with those obtained by time‐dependent density functional theory with the PBE0 functional. The conformational dependence of the transition energies and other properties of free‐chain permethylated n‐hexasilane, n‐Si6Me14, was also examined as a function of dihedral angles, and the striking effects found were attributed to avoided crossings between configurations of σσ* and σπ* character. 相似文献
205.
206.
Yuki H Tanaka Y Hata M Ishikawa H Neya S Hoshino T 《Journal of computational chemistry》2007,28(6):1091-1099
No explicit pi-pi interaction term has been incorporated in the conventional molecular dynamics (MD) simulation programs in spite of its significant role in the folding of biomolecules and the clustering of organic chemicals. In this article, we propose a technique to emphasize the effect of pi-pi interactions using a function of energy and implement it into an MD simulation program. Several trial calculations show that the pi-pi incorporated program gives improved results consistent with experimental data on atom geometry and has no unfavorable interference with the conventional computational framework. This indicates an importance of the explicit consideration of pi-pi interactions in MD simulation. 相似文献
207.
Application to Photocatalytic H2 Production of a Whole‐Cell Reaction by Recombinant Escherichia coli Cells Expressing [FeFe]‐Hydrogenase and Maturases Genes 下载免费PDF全文
Dr. Yuki Honda Prof. Hidehisa Hagiwara Prof. Shintaro Ida Prof. Tatsumi Ishihara 《Angewandte Chemie (International ed. in English)》2016,55(28):8045-8048
A photocatalytic H2 production system using an inorganic–bio hybrid photocatalyst could contribute to the efficient utilization of solar energy, but would require the development of a new approach for preparing a H2‐forming biocatalyst. In the present study, we constructed a recombinant strain of Escherichia coli expressing the genes encoding the [FeFe]‐hydrogenase and relevant maturases from Clostridium acetobutylicum NBRC 13948 for use as a biocatalyst. We investigated the direct application of a whole‐cell of the recombinant E. coli. The combination of TiO2, methylviologen, and the recombinant E. coli formed H2 under light irradiation, demonstrating that whole cells of the recombinant E. coli could be employed for photocatalytic H2 production without any time‐consuming and costly manipulations (for example, enzyme purification). This is the first report of the direct application of a whole‐cell reaction of recombinant E. coli to photocatalytic H2 production. 相似文献
208.
Direct Transformation of Molecular Dinitrogen into Ammonia Catalyzed by Cobalt Dinitrogen Complexes Bearing Anionic PNP Pincer Ligands 下载免费PDF全文
Dr. Shogo Kuriyama Dr. Kazuya Arashiba Prof. Dr. Hiromasa Tanaka Yuki Matsuo Dr. Kazunari Nakajima Prof. Dr. Kazunari Yoshizawa Prof. Dr. Yoshiaki Nishibayashi 《Angewandte Chemie (International ed. in English)》2016,55(46):14291-14295
The direct formation of ammonia from molecular dinitrogen under mild reaction conditions was achieved by using new cobalt dinitrogen complexes bearing an anionic PNP‐type pincer ligand. Up to 15.9 equivalents of ammonia were produced based on the amount of catalyst together with 1.0 equivalent of hydrazine (17.9 equiv of fixed nitrogen atoms). 相似文献
209.
Modification of Wide‐Band‐Gap Oxide Semiconductors with Cobalt Hydroxide Nanoclusters for Visible‐Light Water Oxidation 下载免费PDF全文
Prof. Dr. Kazuhiko Maeda Koki Ishimaki Yuki Tokunaga Dr. Daling Lu Dr. Miharu Eguchi 《Angewandte Chemie (International ed. in English)》2016,55(29):8309-8313
Cobalt‐based compounds, such as cobalt(II) hydroxide, are known to be good catalysts for water oxidation. Herein, we report that such cobalt species can also activate wide‐band‐gap semiconductors towards visible‐light water oxidation. Rutile TiO2 powder, a well‐known wide‐band‐gap semiconductor, was capable of harvesting visible light with wavelengths of up to 850 nm, and thus catalyzed water oxidation to produce molecular oxygen, when decorated with cobalt(II) hydroxide nanoclusters. To the best of our knowledge, this system constitutes the first example that a particulate photocatalytic material that is capable of water oxidation upon excitation by visible light can also operate at such long wavelengths, even when it is based on earth‐abundant elements only. 相似文献
210.
Inside Cover: Direct Transformation of Molecular Dinitrogen into Ammonia Catalyzed by Cobalt Dinitrogen Complexes Bearing Anionic PNP Pincer Ligands (Angew. Chem. Int. Ed. 46/2016) 下载免费PDF全文