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排序方式: 共有174条查询结果,搜索用时 281 毫秒
111.
The first successful Pd-catalyzed intramolecular ipso-Friedel-Crafts allylic alkylation of phenols, which provided a new access to spiro[4.5]cyclohexadienones, is described. The present method could be applied to catalytic enantioselective construction of an all-carbon quaternary spirocenter. 相似文献
112.
Watanabe S Fukuchi Y Fukasawa M Sassa T Uchiyama M Yamashita T Matsumoto M Aoyama T 《Langmuir : the ACS journal of surfaces and colloids》2012,28(28):10305-10309
Donor and acceptor spatial distributions were directly formed in a surface relief grating of structured bulk heterojunction (BHJ) photovoltaic devices by simple periodic photopolymerization. Enhanced photocurrents were observed in the structured BHJ photovoltaic devices and formation of the D/A spatial distribution was confirmed by Kelvin probe force microscopy. This technique enables the fabrication of structured BHJ photovoltaic devices with solution-processable organic semiconductors, and has tremendous potential for controlling D/A spatial distribution in organic optoelectronics devices. 相似文献
113.
An acid-promoted novel skeletal rearrangement is described. Using trifluoroacetic acid as the acid promoter, an intramolecular ipso-Friedel-Crafts-type addition of phenols to 3-alkylidene indolenium cations, formation of iminium cations through rearomatization of the spirocyclohexadienone units, and intramolecular Pictet-Spengler reaction proceeded sequentially, producing tricyclic indole derivatives. 相似文献
114.
Kenichi Kanno Akimitsu Kugimiya Yasumasa Matsumoto Yuya Konishi Tsuyoshi Arakawa Yuichiro Takaki Yuya Yoshida Keiichiro Hanada Kotaro Matsumura Takeshi Endo 《Macromolecular Symposia》2010,297(1):108-113
Summary: Phenylenediamine derivatives (PDs) are environmentally hazardous, though very useful for chemical analysis. To minimize release into the environment, a PD-containing epoxy resin film was developed that retained redox enzyme activity. p-Phenylenediamine and 2,2-bis(4-glycidyloxyphenyl)-propane were cured to produce a violet film. This film was reactive against peroxidase, a redox enzyme that oxidizes phenylenediamine to afford an imine. Enzymatic oxidation caused the film to change color from violet to deep green. The film exhibited fluorescence at 394 nm under excitation at 350 nm, and the fluorescent intensity decreased with greater oxidation. Thus, the film could be used to detect redox enzyme activity. 相似文献
115.
The intermetallic compound H (Mn7Si2V) phase in the Mn–Si–V alloy system can be regarded as an approximant phase of the dodecagonal quasicrystal as one of the two-dimensional quasicrystals. To understand the features of the approximant H phase, in this study, the crystallographic features of both the H phase and the (σ → H) reaction in Mn–Si–V alloy samples were investigated, mainly by transmission electron microscopy. It was found that, in the H phase, there were characteristic structural disorders with respect to an array of a dodecagonal structural unit consisting of 19 dodecagonal atomic columns. Concretely, penetrated structural units consisting of two dodecagonal structural units were presumed to be typical of such disorders. An interesting feature of the (σ → H) reaction was that regions with a rectangular arrangement of penetrated structural units (RAPU) first appeared in the σ matrix as the initial state, and H regions were then nucleated in contact with RAPU regions. The subsequent conversion of RAPU regions into H regions eventually resulted in the formation of the approximant H state as the final state. Furthermore, atomic positions in both the H structure and the dodecagonal quasicrystal were examined using a simple plane-wave model with 12 plane waves. 相似文献
116.
Platinum‐Catalyzed Friedel–Crafts‐Type C−H Coupling–Allylic Amination Cascade to Synthesize 3,4‐Fused Tricyclic Indoles
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Yuta Suzuki Yuito Tanaka Shun‐ichi Nakano Dr. Kosuke Dodo Natsumi Yoda Dr. Ken‐ichi Shinohara Dr. Kazuko Kita Prof. Dr. Atsushi Kaneda Dr. Mikiko Sodeoka Prof. Dr. Yasumasa Hamada Prof. Dr. Tetsuhiro Nemoto 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(13):4418-4421
A novel platinum‐catalyzed cascade cyclization reaction was developed by intramolecular Friedel–Crafts‐type C?H coupling of aniline derivatives with a propargyl carbonate unit‐allylic amination sequence. Treatment of various propargyl carbonates tethered to meta‐aniline derivatives with a Pt(dba)3/DPEphos catalyst system afforded the corresponding 3,4‐fused tricyclic 3‐alkylidene indolines in 42–99 % yield, which were transformed into 3,4‐fused indole derivatives by reaction with trifluoroacetic acid. The reaction products exhibited antiproliferative activities against cancer cells, but not normal cells, revealing the potential usefulness of this reaction for medicinal chemistry. 相似文献
117.
Lablanquie P Huttula SM Huttula M Andric L Palaudoux J Eland JH Hikosaka Y Shigemasa E Ito K Penent F 《Physical chemistry chemical physics : PCCP》2011,13(41):18355-18364
Auger decay of an inner shell hole is an efficient way to create multiply charged ions in the gas phase. We illustrate this with the example of the argon 2s decay, and show that multi-electron coincidence spectroscopy between the 2s photoelectron and all released Auger electrons leads to a complete reconstruction of the Ar 2s decay cascade. Spectra of the intermediate and final Ar(n+) states are obtained and are compared with a theoretical model. 相似文献
118.
Hakamada M Takahashi M Furukawa T Tajima K Yoshimura K Chino Y Mabuchi M 《Physical chemistry chemical physics : PCCP》2011,13(26):12277-12284
Desorption of thiolate self-assembled monolayers (SAMs) seriously limits the fabrication of thiol-based devices. Here we demonstrate that nanoporous Au produced by dealloying Au-Ag alloys exhibits high electrochemical stability against thiolate desorption. Nanoporous Au has many defective sites, lattice strain and residual Ag on the ligament surface. First-principles calculations indicate that these surface aspects increase the binding energy between a SAM and the surface of nanoporous Au. 相似文献
119.
We developed a novel (S)-L-phenylalanine derived-bidentate chiral diaminophosphine oxide (DIAPHOX) preligand (S,S(P))-9b, which was successfully applied to Pd-catalyzed asymmetric allylic alkylation and amination. Using the Pd-(S,S(P))-9b catalyst system, asymmetric allylic alkylation and amination proceeded very smoothly, affording the corresponding products in excellent yield with high enantiomeric excess. It is noteworthy that both enantiomers were accessible with high enantiomeric purity using the structurally related DIAPHOX preligands (S,S(P))-9b and a monodentate chiral diaminophosphine oxide preligand (S,R(P))-10a, both of which can be prepared from a single chiral source, (S)-L-phenylalanine. 相似文献
120.
Nakagaki T Iima M Ueda T Nishiura Y Saigusa T Tero A Kobayashi R Showalter K 《Physical review letters》2007,99(6):068104
When two food sources are presented to the slime mold Physarum in the dark, a thick tube for absorbing nutrients is formed that connects the food sources through the shortest route. When the light-avoiding organism is partially illuminated, however, the tube connecting the food sources follows a different route. Defining risk as the experimentally measurable rate of light-avoiding movement, the minimum-risk path is exhibited by the organism, determined by integrating along the path. A model for an adaptive-tube network is presented that is in good agreement with the experimental observations. 相似文献