著者

Atsuhiro Osuka Hitomi Suzuki Kazuhiro Maruyama

出版者

(社)日本化学会

雑誌

Chemistry Letters (ISSN:03667022)

巻号頁・発行日

vol.11, no.5, pp.653-656, 1982-05-05 (Released:2006-03-27)

参考文献数

12

被引用文献数

1

---

Photolysis of the title compounds in benzene gave spirophthalides and E- and Z-alkylidene phthalides via preferential α-cleavage at the more crowded side. On the basis of quantum yields and triplet lifetimes, this preference is indicated to arise from the different efficiencies of the radical recombination of possible biradicals.

著者

Kazuhiro Maruyama Atsuhiro Osuka Katsuhiko Nakagawa Kenzo Tabuchi Hirohito Shimizu Hitomi Suzuki

出版者

(社)日本化学会

雑誌

Chemistry Letters (ISSN:03667022)

巻号頁・発行日

vol.15, no.11, pp.1849-1852, 1986-11-05 (Released:2006-03-27)

参考文献数

7

被引用文献数

1

---

Irradiation of 2-substituted 4-alkylidene-2,3-epoxy-1-tetralone results in the rearrangement to 3-(2-oxoalkylidene)-1-indanone or the E-Z isomerization around the double bond. These photoreactions are suggested to occur from the (π,π*) triplet excited state.

著者

Joe Otsuki Koichi Narutaki Jan M. Bakke

出版者

(社)日本化学会

雑誌

Chemistry Letters (ISSN:03667022)

巻号頁・発行日

vol.33, no.3, pp.356-357, 2004 (Released:2004-02-23)

参考文献数

16

被引用文献数

26

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Modulation of luminescence intensity triggered by light input is demonstrated. The system consists of a Zn–porphyrin and an azopyridine derivative, which axially coordinates to Zn–porphyrin and quenches its fluorescence more efficiently in the trans-form than in the cis-form. Thus, light-induced isomerization of the azopyridine results in the increase/decrease of the porphyrin fluorescence.

著者

Satoru Tsukada Ryota Sakamoto Hiroshi Nishihara

出版者

The Chemical Society of Japan

雑誌

Chemistry Letters (ISSN:03667022)

巻号頁・発行日

vol.41, no.4, pp.357-359, 2012-04-05 (Released:2012-03-17)

参考文献数

43

被引用文献数

4

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[{Cp*Rh(S2C6H4)}2W(CO)2] (Cp*: η5-C5Me5) (1) and [{Cp*Rh(S2C6H4)}(S2C6H4)W(CO)2] (2) were synthesized by the reaction of rhodadithiolene [Cp*Rh(S2C6H4)] with [W(CO)3(py)3], and their crystal structures and physical properties were investigated. The formation mechanism of 2 from 1 was pursued by 1H NMR spectroscopy. 1 reacted with an excess amount of BF3·Et2O to furnish 2, indicating that a Lewis acid assisted the demetalation reaction.

著者

Ryohei Yamakado Shinri Sugimoto Shin-ichi Matsuoka Masato Suzuki Yasuhiro Funahashi Koji Takagi

出版者

(社)日本化学会

雑誌

Chemistry Letters (ISSN:03667022)

巻号頁・発行日

vol.41, no.3, pp.249-251, 2012-03-05 (Released:2012-02-25)

参考文献数

18

被引用文献数

9

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m-Calix[3]amide having pyridine on the benzene ring (PyC3A) was synthesized by the cyclization of methyl 3-nonylamino-5-(pyridin-4-yl)benzoate using lithium 1,1,1,3,3,3-hexamethyldisilazide (LiHMDS). The molecular cage 3Pd·2PyC3A was prepared from a 2:3 mixture of PyC3A and [Pd(dppp)(OTf)2] in CDCl3/CD3OD (5/1 in volume). On the other hand, in CDCl3, the formation of a polymeric mixture was confirmed.

著者

Kazuki Ogata Daisuke Sasano Tomoya Yokoi Katsuhiro Isozaki Hirofumi Seike Nobuhiro Yasuda Tetsuya Ogawa Hiroki Kurata Hikaru Takaya Masaharu Nakamura

出版者

(社)日本化学会

雑誌

Chemistry Letters (ISSN:03667022)

巻号頁・発行日

vol.41, no.2, pp.194-196, 2012-02-05 (Released:2012-02-04)

参考文献数

42

被引用文献数

15

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Novel NCN-pincer Pd-complex-bound norvaline derivatives were synthesized. The N- and C-termini-alkylated Pd–norvalines spontaneously assemble into fibrous aggregates to form supramolecular gels, in which the NCN-pincer Pd complex moieties assemble in a highly oriented manner.

著者

Hiroyoshi Sugino Hidetoshi Kawai Kenshu Fujiwara Takanori Suzuki

出版者

(社)日本化学会

雑誌

Chemistry Letters (ISSN:03667022)

巻号頁・発行日

vol.41, no.1, pp.79-81, 2012-01-05 (Released:2011-12-30)

参考文献数

23

被引用文献数

8

---

Condensation reactions of macrocyclic diamines 1 and cyclohexane-1,4-dicarbaldehydes 2 with the substituents at 1,4-positions gave a series of macrocage molecules that can be considered molecular gyroscopes. The gyro-rotational behavior of the cyclohexane rotor is largely affected by the degree of steric requirement of the substituents, and isolation of syn-isomer suggests stepwise motion in the macrocages attached with bulky substituents on the rotor.

著者

Toshiaki Murai Yuichiro Mutoh

出版者

(社)日本化学会

雑誌

Chemistry Letters (ISSN:03667022)

巻号頁・発行日

vol.41, no.1, pp.2-8, 2012-01-05 (Released:2011-12-24)

参考文献数

99

被引用文献数

67

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Sequential reactions of thioamides and thioformamides with organolithium and Grignard reagents are described. Thioiminium salts derived from these sulfur isologues of amides readily react with lithium acetylides to lead to several types of products, including α,β-unsaturated ketones, whereas sequential additions of lithium acetylides and Grignard reagents afford propargylamines. The direct addition of organolithium and Grignard reagents to thioformamides proceeds with high efficiency to give a range of tertiary amines.

著者

Ryota Sakamoto Koya Prabhakara Rao Hiroshi Nishihara

出版者

The Chemical Society of Japan

雑誌

Chemistry Letters (ISSN:03667022)

巻号頁・発行日

vol.40, no.12, pp.1316-1326, 2011-12-05 (Released:2011-11-26)

参考文献数

94

被引用文献数

22

---

In this account we describe ethynylene-conjugated arylethynylanthraquinone (ArAq) and bis(arylethynyl)anthraquinone (Ar2Aq) which possess ferrocene, triarylamine, platinadithiolene complex, p-methoxybenzene, p-methylbenzene, m-methylbenzene, and benzene as electron-donating arenes (Ar), and anthraquinone (Aq) as an electron acceptor. This series of compounds features donor–acceptor (D–A) interactions: (1) Expression of intramolecular charge-transfer (ICT) transitions; (2) flexible single crystal networks constructed by intermolecular D–A π–π stacking, which undergo guest-induced reversible crystal-to-crystal transformations. In addition, ArAq and Ar2Aq experience proton-induced cyclization so as to produce pyrylium and dipyrylium salts. These salts feature further expanded π-conjugation and stronger D–A interaction: (1) More red-shifted ICT transitions and narrower HOMO–LUMO gaps; (2) bright fluorescence; (3) valence tautomerism (VT); (4) unique reactivities.

著者

Ying-Wu Lin Chang-Ming Nie Li-Fu Liao

出版者

The Chemical Society of Japan

雑誌

Chemistry Letters (ISSN:03667022)

巻号頁・発行日

vol.40, no.12, pp.1330-1331, 2011-12-05 (Released:2011-11-09)

参考文献数

27

被引用文献数

4

---

Uranium is toxic to the human body with mechanisms not fully understood. The interaction between uranyl ion (UO22+) and ubiquitin (Ub) was predicted by molecular modeling, molecular dynamics (MD) simulation, and steered molecular dynamics (SMD) simulation. The structural and dynamics consequences, as well as protein unfolding behavior, upon uranyl binding to two surface residues of Ub, Glu18 and Asp21, were revealed at an atomic level. This in silico study exhibits a possibility of UO22+ binding to Ub, providing a possible mechanism of uranyl toxicity in vivo.

著者

Hideki Sugimoto Reiko Tajima Kazuo Toyota Hiroyuki Miyake Shinobu Itoh

出版者

(社)日本化学会

雑誌

Chemistry Letters (ISSN:03667022)

巻号頁・発行日

vol.40, no.10, pp.1146-1148, 2011-10-05 (Released:2011-09-28)

参考文献数

22

被引用文献数

1

---

The reaction of bis(dithiolene)sulfidotungsten(IV) complex with elemental sulfur yielded bis(dithiolene)(tetrasulfido)tungsten(IV) complex. A labeling experiment using 34S has indicated that the reaction is reversible and a sulfido(trisulfido)tungsten(VI) species is involved as an intermediate. The reaction represents a model reaction of polysulfide reductase of molybdoenzymes.

著者

Noriki Kutsumura Masatoshi Iijima Shohei Toguchi Takao Saito

出版者

The Chemical Society of Japan

雑誌

Chemistry Letters (ISSN:03667022)

巻号頁・発行日

vol.40, no.11, pp.1231-1232, 2011-11-05 (Released:2011-10-08)

参考文献数

21

被引用文献数

8

---

We have investigated the DBU-promoted HBr-elimination of vicinal dibromides having an adjacent O- and/or N-functional group under mild basic conditions. The elimination of 1-oxygen-functionalized 2,3-dibromopropanes was more regioselective than that of 1-nitrogen-functionalized 2,3-dibromopropanes. This observation suggests that the elimination selectivity is affected by the electronegativity of the neighboring heteroatoms themselves and not by the entire functional group.

著者

Akira Suzuki Yasunori Yamamoto

出版者

(社)日本化学会

雑誌

Chemistry Letters (ISSN:03667022)

巻号頁・発行日

vol.40, no.9, pp.894-901, 2011-09-05 (Released:2011-09-05)

参考文献数

88

被引用文献数

145

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The palladium-catalyzed cross-coupling reaction between different types of organoboron compounds and various organic halides or triflates in the presence of base provides a powerful and general methodology for the formation of carbon–carbon bonds. The Csp2–B compounds (such as aryl- and 1-alkenylboron derivatives) and Csp3–B compounds (alkylboron compounds) readily cross-couple with organic electrophiles to give coupled products selectively in high yields. Recently, the Csp–B compounds (1-alkynylboron derivatives) have been also observed to react with organic electrophiles to produce expected cross-coupled products. The overview of some of such coupling reactions is discussed here in this article.

著者

Takuya Kochi Aoi Tazawa Kazuki Honda Fumitoshi Kakiuchi

出版者

The Chemical Society of Japan

雑誌

Chemistry Letters (ISSN:03667022)

巻号頁・発行日

vol.40, no.9, pp.1018-1020, 2011-09-05 (Released:2011-09-05)

参考文献数

49

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Ruthenium-catalyzed ortho-selective acylation of arylpyridines with acyl chlorides via C–H bond cleavage is described. Aromatic acyl chlorides as well as α,β-unsaturated acyl chlorides were coupled with arylpyridines to give aromatic ketones in the presence of [RuCl2(PPh3)3] as a catalyst and potassium carbonate as a base.

著者

Takanori Kotera Masahiro Mikuriya

出版者

The Chemical Society of Japan

雑誌

Chemistry Letters (ISSN:03667022)

巻号頁・発行日

vol.31, no.7, pp.654-655, 2002 (Released:2002-07-05)

参考文献数

18

被引用文献数

4

---

Thiolato-bridged hexanuclear mixed-valence complex, [CuI3CuII3(apampt)3Cl6] (Hapampt=1-[(3-aminopropyl)amino]-2-methylpropane-2-thiol), has been synthesized and characterized by X-ray crystallography. Spectroscopic data as well as structural features support a localized mixed-valence state. Magnetic susceptibility data show that a strong antiferromagnetic interaction is operating between the CuII ions.

著者

Hayato Tsuji Guillaume Marcel Olivier Favier Chikahiko Mitsui Sunri Lee Daisuke Hashizume Eiichi Nakamura

出版者

(社)日本化学会

雑誌

Chemistry Letters (ISSN:03667022)

巻号頁・発行日

vol.40, no.6, pp.576-578, 2011-06-05 (Released:2011-04-28)

参考文献数

38

被引用文献数

23

---

2,6-Di(2-pyridyl)benzo[1,2-b:4,5-b′]difuran (2-PyBDF) shows a π–π-stacking packing structure in a single crystal and some intriguing properties: mechanochromism in the solid state, and solvent and concentration dependence of absorption and emission spectra.

著者

Shinji Toyota Takamasa Shimizu Tetsuo Iwanaga Kan Wakamatsu

出版者

The Chemical Society of Japan

雑誌

Chemistry Letters (ISSN:03667022)

巻号頁・発行日

vol.40, no.3, pp.312-314, 2011-03-05 (Released:2011-02-19)

参考文献数

35

被引用文献数

24

---

The title compounds having two 9-triptycyl rotors, two acetylene shafts, and an acene base were synthesized by coupling reactions as molecular spur gears. Their molecular structures were compared to evaluate the meshing of rotor moieties and the orientation of the two gear shafts. The mechanism of rotation of three-toothed rotors was explored by NMR spectroscopy and DFT calculations in terms of gear rotation and slippage.

著者

Tsuneomi Kawasaki Hitomi Ozawa Masateru Ito Kenso Soai

出版者

The Chemical Society of Japan

雑誌

Chemistry Letters (ISSN:03667022)

巻号頁・発行日

vol.40, no.3, pp.320-321, 2011-03-05 (Released:2011-02-19)

参考文献数

40

被引用文献数

38

---

Enantioselective synthesis has been achieved using chiral compounds arising from mono- and dideuterated methyl groups as chiral inducers in conjunction with asymmetric autocatalysis. The absolute configuration of the product was controlled by the small degree of chirality generated by the difference between the partially deuterated methyl groups (CDH2 and CD2H) and the non-deuterated methyl group (CH3) in N-benzoyl-α-methylalanine.

著者

Eiko Mieda Takahiro Sasamori Shohei Sase Kei Goto Norihiro Tokitoh

出版者

The Chemical Society of Japan

雑誌

Chemistry Letters (ISSN:03667022)

巻号頁・発行日

vol.40, no.2, pp.196-197, 2011-02-05 (Released:2011-01-22)

参考文献数

18

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We report here the attempted synthesis of a stable 1-fluoro-2-hydrosilene bearing a Bpq group, which is a bulky aryl group bearing a cavity-shaped framework. We have successfully synthesized an overcrowded benzyldifluorosilane as a precursor. Treatment of the benzyldifluorosilane with 2 equiv of t-BuOK in THF afforded the corresponding benzyl anion, the structure of which showed a unique feature as a fluorosilene–KF complex.

著者

Izumi Iwakura Atushi Yabushita Takayoshi Kobayashi

出版者

The Chemical Society of Japan

雑誌

Chemistry Letters (ISSN:03667022)

巻号頁・発行日

vol.39, no.4, pp.374-375, 2010-04-05 (Released:2010-03-06)

参考文献数

34

被引用文献数

28

---

The detailed processes in the Claisen rearrangement were observed. The process was vibrationally excited in the electronic ground state by a stimulated Raman process using a 5-fs pulse. The Claisen rearrangement was found to follow a three-step pathway. At first, the C4–O bond is weakened to generate a bis-allyl-like intermediate. Next, the formation of a weak C1–C6 bond results in the generation of an aromatic-like intermediate. Finally, C4–O breaking and C1–C6 formation occur simultaneously to generate the product.