著者

Jiao Jiao Kei Murakami Kenichiro Itami

出版者

(社)日本化学会

雑誌

Chemistry Letters (ISSN:03667022)

巻号頁・発行日

pp.160133, (Released:2016-02-25)

被引用文献数

14

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Methods that can directly arylate pyridines have significant potential in synthetic chemistry. Herein, we present a palladium-catalyzed C–H arylation of pyridines with aryl triflates that occurs regioselectively at the C3 positions of pyridine core. A variety of aryl triflates and pyridines were applicable to the reaction to provide C3-arylated pyridines regardless of sterics or electronics of the pyridine cores.

著者

Yi-Chou Tsai Chih-Chieh Chang

出版者

(社)日本化学会

雑誌

Chemistry Letters (ISSN:03667022)

巻号頁・発行日

vol.39, no.4, pp.311-311, 2010-04-05 (Released:2010-04-05)

著者

Shinji Toyota Takao Yamamori Mitsuhiro Asakura Michinori Oki

出版者

(社)日本化学会

雑誌

Bulletin of the Chemical Society of Japan (ISSN:00092673)

巻号頁・発行日

vol.73, no.1, pp.205-213, 2000 (Released:2001-10-31)

参考文献数

37

被引用文献数

28

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The substituent effect on the rotational barriers of acetylenic to tetrahedral C-C bonds was studied for the title compounds carrying Me or OMe substituents at the 1,4-positions in the 9-triptycyl groups. These compounds were prepared by use of the Diels-Alder and the Sonogashira reactions from a 9-ethynylanthracene derivative. The kinetic parameters were determined by the total lineshape analysis of the signals observed by the variable temperature 1H NMR for five compounds. The rotational barriers are in the range of 9—15 kcal mol-1, and are enhanced as the steric size of the substituents is increased (H < OMe < Me). This substituent effect is attributed to the destabilization of the transition state of the rotation process, where the two triptycyl groups are almost eclipsed about the central axis, by the steric interactions between the peri substituents. The acetylenic carbons are significantly deformed from the linear geometry in the X-ray structure of the tetramethyl compound. The substituent effect on the rotamer population is also discussed with the aid of the MM calculation.

著者

Haruna Sawaguchi Hiroshi Nishida Takahiro Kawai Hiroyuki Mayama Yoshimune Nonomura

出版者

(社)日本化学会

雑誌

Chemistry Letters (ISSN:03667022)

巻号頁・発行日

pp.150005, (Released:2015-02-14)

被引用文献数

1

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We prepared an apatite/polymer composite material with a fractal surface by transferring the hierarchical rough surface of a plaster replica onto calcium phosphate paste and immersing the paste in buffer. The rough structure (fractal dimension = 2.3) accelerated the spreading and penetration of a water droplet placed on the surface. This material can be applied in dental implants and texture testers.

著者

Yoshimune Nonomura Azusa Yamaguchi

出版者

(社)日本化学会

雑誌

Chemistry Letters (ISSN:03667022)

巻号頁・発行日

pp.151033, (Released:2015-12-16)

被引用文献数

1

---

The friction behavior of water and thickener aqueous solutions was evaluated between a contact probe with a striped rough surface and a substrate. When the probe surface is flat, the contact state is boundary lubrication and fluid film lubrication states for water and thickener aqueous solutions, respectively. In contrast, in the case of the contact probe with a striped rough surface, friction occurred under fluid lubrication state for both water and thickener solutions. These results indicate that the liquid in the depression on the striped rough surfaces change the regime of friction.

著者

Shoichi Nakano

出版者

(社)日本化学会

雑誌

Bulletin of the Chemical Society of Japan (ISSN:00092673)

巻号頁・発行日

vol.29, no.2, pp.219-224, 1956 (Released:2006-04-12)

参考文献数

20

被引用文献数

4 3

著者

Jing-Dong Guo Takahiro Sasamori Yutaro Yamamoto Hiroshi Matsubara Shigeru Nagase Hideki Yorimitsu

出版者

(社)日本化学会

雑誌

Bulletin of the Chemical Society of Japan (ISSN:00092673)

巻号頁・発行日

pp.20150343, (Released:2015-11-16)

被引用文献数

4

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The previously reported palladium-catalyzed silylation of aryl chlorides with silylsilatranes were theoretically reinvestigated by DFT calculations with a focus on the effect of the transannular Si–N coordination on silyl transfer. The Si–N coordination proved to be not so influential as to accelerate the silyl transfer. However, it should be of benefit to use silylsilatranes as silylating agents because of their easy handling and facile preparation.

著者

Naoki Aratani Atsuhiro Osuka

出版者

(社)日本化学会

雑誌

Bulletin of the Chemical Society of Japan (ISSN:00092673)

巻号頁・発行日

vol.88, no.1, pp.1-27, 2015-01-15 (Released:2015-01-15)

参考文献数

241

被引用文献数

35 1

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Directly linked linear porphyrin arrays were synthesized and their photophysical properties depending on the length of the arrays were investigated. Ag(I)-promoted oxidative coupling of 5,15-diaryl Zn(II) porphyrins has proven to be effective for preparations of very long meso–meso-linked Zn(II) porphyrin arrays (Zn). A stepwise doubling strategy with strict purification at each doubling step allowed for preparation of gigantic but discrete linear arrays in an unprecedented manner. Large cyclic porphyrin wheels were also synthesized by final meso–meso coupling intramolecular cyclization. Crucial to this success are high reactivity and high regioselectivity of the Ag(I)-promoted oxidative coupling. Equally important are high solubilities of Zn despite their large molecular weights, which arise from their perpendicularly linked structures. Another advantage of this doubling strategy is a large difference in the molecular weights among reactants and products that increases as the reactant array becomes larger, allowing separation of coupling products by preparative GPC-HPLC. As an alternative protocol, Pd-catalyzed Suzuki–Miyaura cross-coupling has been extensively used for synthesis of cyclic porphyrin arrays. This strategy gave novel linear and cyclic porphyrin arrays from β-borylated porphyrins that were prepared by Ir-catalyzed borylation of meso-free porphyrins. As an interesting example, a porphyrin nanotube consisting of four porphyrins doubly bridged by 2,6-pyridinylene spacers was synthesized and revealed to possess a C60-encapsulation capability. Exciton coupling, effective energy hopping, coherent length, and excitation energy transfer of meso–meso-linked linear and cyclic porphyrin arrays are discussed. STM and AFM detections of the large porphyrin arrays are also presented. We believe that these studies expand the range of organic molecules we can manipulate and open a door to a new area of nanoscaled and sub-microscaled functional porphyrin materials.

著者

Ken Tanaka Yuki Kimura Koichi Murayama

出版者

(社)日本化学会

雑誌

Bulletin of the Chemical Society of Japan (ISSN:00092673)

巻号頁・発行日

vol.88, no.3, pp.375-385, 2015-03-15 (Released:2015-03-15)

参考文献数

112

被引用文献数

113 5

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The highly enantioselective synthesis of functionalized helicenes and helicene-like molecules have been achieved via rhodium-catalyzed [2+2+2] cycloaddition reactions. The rhodium-catalyzed enantioselective intramolecular [2+2+2] cycloaddition of 2-naphthol-linked triynes afforded [7]helicene-like molecules in good yields and ee values. The more sterically encumbered reaction, the rhodium-catalyzed enantioselective double intramolecular [2+2+2] cycloaddition of a 2-naphthol-linked hexayne, also proceeded to give a [11]helicene-like molecule with high ee value, although the product yield was low. Not only intramolecular cycloaddition reactions but also intermolecular ones were accomplished by combinations of electron-rich tetraynes and electron-poor diynes to give [7]- and [9]helicene-like molecules and [7]helicenes in varying yields and ee values.

著者

Yoshiki Chujo Kazuo Tanaka

出版者

(社)日本化学会

雑誌

Bulletin of the Chemical Society of Japan (ISSN:00092673)

巻号頁・発行日

vol.88, no.5, pp.633-643, 2015-05-15 (Released:2015-05-15)

参考文献数

45

被引用文献数

301 11

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The concept and representative examples of “element-block polymers” are described. A structural unit consisting of various groups of elements is called an “element-block.” In this review, unique properties of “element-block polymers” composed of organoboron complexes, o-carboranes, and polyhedral oligomeric silsesquioxanes as typical examples of element blocks are illustrated. The design and synthesis of new element-blocks and development of methods forming higher-order structures for realizing the desired functions based on a bottom-up approach are explained.

著者

Sarah A. Weicker Douglas W. Stephan

出版者

(社)日本化学会

雑誌

Bulletin of the Chemical Society of Japan (ISSN:00092673)

巻号頁・発行日

vol.88, no.8, pp.1003-1016, 2015-08-15 (Released:2015-08-15)

参考文献数

107

被引用文献数

103

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The advent of frustrated Lewis pair (FLP) chemistry almost a decade ago was based on the reactivity of sterically encumbered combinations of electrophilic boranes and phosphines with hydrogen. Since that time the chemistry has broadened dramatically in terms of reactivity and applications. Nonetheless, the majority of the work has continued to exploit the borane B(C6F5)3. In this review, we describe FLP chemistry that has developed by employing alternatives to this Lewis acid. Lewis acids derived from group 13, 14, and 15 based systems are described, thus demonstrating a growing area in the main group reactivity based on FLPs.

著者

Atsushi Wakamiya Shigehiro Yamaguchi

出版者

(社)日本化学会

雑誌

Bulletin of the Chemical Society of Japan (ISSN:00092673)

巻号頁・発行日

vol.88, no.10, pp.1357-1377, 2015-10-15 (Released:2015-10-15)

参考文献数

179

被引用文献数

218

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Boron, a group 13 element, has several characteristic structural and electronic features: 1) trivalent boron compounds usually adopt a trigonal planar geometry; 2) due to the presence of a vacant p-orbital, effective orbital interaction with π-conjugated compounds is possible; 3) the presence of a vacant p-orbital is furthermore responsible for high Lewis acidity; 4) the boryl group acts as a π-electron-accepting group particularly in the excited state. The consequent exploitation of these characteristic features of boron in the molecular design enables us to produce sophisticated π-functional materials with attractive photophysical and electronic properties. This account article illustrates our systematic studies on the molecular design and the development of functional π-electron materials using boron as a key element.

著者

Kazuhiko Takai

出版者

(社)日本化学会

雑誌

Bulletin of the Chemical Society of Japan (ISSN:00092673)

巻号頁・発行日

vol.88, no.11, pp.1511-1529, 2015-11-15 (Released:2015-11-15)

参考文献数

133

被引用文献数

8

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During the development of new synthetic organic reactions by the use of group 4–7 metals, we twice encountered a reproducibility problem. The key factor was trace amounts of second metal elements that contaminated the first, main metals, i.e., nickel in chromium and lead in zinc. We had determined the standard procedures for these reactions and they were adopted in Organic Syntheses. The difference in the source of zinc, i.e., contamination by a catalytic amount of lead, proved to affect both the reactivity of the Simmons–Smith reaction and the formation of alkylzinc from the corresponding iodides. By using the concept of catalytic effects of the second metals, we developed a method to use manganese metal and applied this to sequential radical and anionic reactions. In addition, allylic aluminum species were prepared smoothly from allylic halides and aluminum by addition of an indium salt, the second element. In this account, I describe how the synthetic methods were discovered and developed, with an emphasis on the stories behind the communications and articles.

著者

Kanji Miyabe Youki Shimazaki

出版者

(社)日本化学会

雑誌

Bulletin of the Chemical Society of Japan (ISSN:00092673)

巻号頁・発行日

pp.20150203, (Released:2015-08-25)

被引用文献数

12

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We developed a capillary electrophoretic (CE) method for the kinetic study of intermolecular interactions. Neither immobilization nor chemical modification, e.g., fluorescence labelling, of solute and ligand molecules is required. A concept of chromatographic capillary electrophoresis (CCE) was introduced as an experimental CE procedure. In the CCE mode, the migration of solute-ligand complex in a capillary is stopped. Only solute molecule migrates and is detected. New moment equations were developed, which were essential for determining association and dissociation rate constants from elution peak profiles measured under the CCE conditions. The combination of the CCE concept and the moment theory leads to the CE method, i.e., moment analysis by CCE (MACCE). However, because it was hard to really perform CE experiments under the CCE conditions, we also developed practical experimental and data analysis procedures for the MACCE measurement. The reaction rate constants were analytically determined by the MACCE method for the formation and dissociation of the inclusion complex between thymol and sulfated-β-cyclodextrin. It is unnecessary to fit elution curves numerically calculated to those experimentally measured for determining the rate constants. It was demonstrated that the MACCE method was effective for the kinetic study of intermolecular interactions.

著者

Kazuhiko Saigo Naomi Kubota Shoko Takebayashi Masaki Hasegawa

出版者

(社)日本化学会

雑誌

Bulletin of the Chemical Society of Japan (ISSN:00092673)

巻号頁・発行日

vol.59, no.3, pp.931-932, 1986 (Released:2006-06-27)

参考文献数

9

被引用文献数

61

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(±)-1,2-Diphenylethylenediamine (DPEDA) was efficiently resolved by the fractional crystallization of its diastereomeric salts with optically active mandelic acid. 1H-NMR spectrum of N-monoacylated DPEDA with an optically active derivatizing agent showed that DPEDA thus obtained was optically pure.

著者

Hajime Maeda Hirofumi Mukae Kazuhiko Mizuno

出版者

(社)日本化学会

雑誌

Chemistry Letters (ISSN:03667022)

巻号頁・発行日

vol.34, no.1, pp.66-67, 2005 (Released:2004-12-11)

参考文献数

26

被引用文献数

76 64

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The intramolecular photocycloaddition of a 1-cyanonaphthalene derivative in microreactors made of poly(dimethylsiloxane) (PDMS) was examined. By using the microreactors and flow system, both the efficiency and regioselectivity increased compared with those under batch conditions.

著者

Suguru Yoshida Takamitsu Hosoya

出版者

(社)日本化学会

雑誌

Chemistry Letters (ISSN:03667022)

巻号頁・発行日

pp.150839, (Released:2015-09-12)

被引用文献数

173

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Recent developments in aryne chemistry are reviewed with a particular focus on synthetic methods. This includes an overview of the precursors of arynes and their activators; the generation of arynes with functional groups and their ensuing reactivities; and the novel transformations achieved via aryne intermediates. These newly developed methods have enabled the synthesis of a variety of previously inaccessible aromatic compounds, allowing the construction of a diversity-enriched chemical library that will further facilitate future drug discoveries.

著者

Ryo Irie Tatsuya Uchida Kazuhiro Matsumoto

出版者

(社)日本化学会

雑誌

Chemistry Letters (ISSN:03667022)

巻号頁・発行日

pp.150747, (Released:2015-08-21)

被引用文献数

25

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The late Emeritus Professor Tsutomu Katsuki, who was leading the field of catalytic asymmetric oxidation worldwide, suddenly passed away on October 30, 2014. Here we wish to commemorate him by highlighting his representative research works particularly on his unique catalytic systems for asymmetric alkene epoxidation, sulfoxidation, alcohol oxidation, oxidative coupling reactions with a personal view and memory.

著者

Viet-Ha Tran Takeshi Yatabe Takahiro Matsumoto Hidetaka Nakai Kazuharu Suzuki Takao Enomoto Seiji Ogo

出版者

(社)日本化学会

雑誌

Chemistry Letters (ISSN:03667022)

巻号頁・発行日

vol.44, no.6, pp.794-796, 2015-06-05 (Released:2015-06-05)

参考文献数

37

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We report the first example of a Ni0 precursor that provides a contamination-free (<1%) nickel film by metal–organic chemical vapor deposition (MOCVD) using N2 as the carrier gas. The structure and physical properties of the Ni0 precursor and subsequent film are described.

著者

Takuro Niidme Masanori Fujii Naotoshi Nakashima Yoshiki Katayama Yasuro Niidome

出版者

(社)日本化学会

雑誌

Chemistry Letters (ISSN:03667022)

巻号頁・発行日

pp.150258, (Released:2015-04-17)

被引用文献数

11

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Gold nanorods were intravenously injected into tumor-bearing mice. The distribution of gold in tumor tissue sections was mapped by imaging mass spectrometry (IMS) using a MALDI mass spectrometer. IMS images of tumor tissue sections indicated that the gold nanorods were not distributed throughout tumor tissues but were localized in vasculature-rich areas.