研究者詳細 - 岡本　秀毅

論文 - 岡本　秀毅

分割表示 105 件中 81 - 100 件目／全件表示 >>

An azacrowned phthalimide as a metal-ion sensitive and solvatofluorochromic fluorophore: Fluorescence properties and a mimic integrated logic operation 査読

H Okamoto, M Kohno, K Satake, M Kimura

BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 78 ( 12 ) 2180 - 2187 2005年12月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：CHEMICAL SOC JAPAN

The novel azacrowned phthalimide 1 has been prepared and its fluorescence properties have been investigated by addition of EtOH and Ag+. The phthalimide 1 showed appreciable solvatofluorochromism; its fluorescence maxima (lambda(FL)) appeared in the wavelength region between 458 (in Et2O) and 544 nm (in EtOH). In benzene, the phthalimide 1 gave off blue emission (lambda(FL) 466 nm) while it emitted green fluorescence (lambda(FL) 497 nm) upon addition of 250 mM of EtOH. Both the blue and the green emissions were quenched by Ag+. Potential logic operations of the phthalimide 1 were examined using fluorescence outputs at 450 (Out(1)) and 515 nm (Out(2)) and two input stimuli, EtOH (In,) and Ag+ (In-2). The Out, was on in the absence of these inputs while its intensity was reduced (off) by either or both of the inputs to serve as a NOR operator. The Out(2) was off without the inputs; in contrast, the intensity of Out(2) was enhanced (on) by In-2. The enhanced Out(2) was switched off by In-2. The Obt(2), thus, corresponds to an INHIBIT operation responding to the input signals. The crowned phthalimide 1 mimics a two-input-two-output combinational logic gate with a single fluorophore and a single ion-sensing unit.

DOI： 10.1246/bcsj.78.2180

Electrophilic behavior of the pi delocalized azepinium ion: Friedel-crafts reactions with benzenes and five-membered aromatic heterocycles 招待

Y Kubota, K Satake, H Okamoto, M Kimura

ORGANIC LETTERS 7 ( 23 ) 5215 - 5218 2005年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER CHEMICAL SOC

Although the reactivity of tropylium ion with aromatic substrates is low, the reaction of azepinium ion with aromatic substrates such as benzene, phenol, furan, and thiophene resulted in the formation of 2-aryl-2H-azepine as a major product. An exceptional result in the formation of ring-contracted product was observed in the reaction with pyrrole.

DOI： 10.1021/ol052049l

Preparation of an azacrowned isoluminol and its chemiluminescence initiated by alkali-metal iodides in acetonitrile 査読

H Okamoto, M Kimura

CHEMISTRY LETTERS 34 ( 10 ) 1452 - 1453 2005年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：CHEMICAL SOC JAPAN

The novel azacrowned isoluminol has been prepared as the first luminol analogue possessing an azacrown ionophore. The crowned isoluminol displayed flash chemiluminescence upon addition of alkali-metal iodides in acetonitrile containing alkaline hydrogen peroxide and the chemiluminescence intensity varied depending on the metal cations studied; K+ >> Na+ > Li+.

DOI： 10.1246/cl.2005.1452

Reaction of 2-methoxy-3H-azepine with NBS: Efficient synthesis of 2-substituted 2H-azepines

CEJ Cordonier, K Satake, M Atarashi, Y Kawamoto, H Okamoto, M Kimura

JOURNAL OF ORGANIC CHEMISTRY 70 ( 9 ) 3425 - 3436 2005年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER CHEMICAL SOC

The reaction of 2-methoxy-3H-azepines, in the presence or absence of a nucleophile, with N-bromosuccinimide (NBS) gave a regioselective 1,4-adduct from which the corresponding 2H-azepine derivatives were formed via base-promoted hydrogen bromide elimination, generally in moderate to quantitative yield. Competitive formation of 4-bromo-2-methoxy-3H-azepine by electrophilic substitutuion or 3H-azepin-2-yl 2H-azepin-2-yl ether by transetherification was minimized at lower reaction temperatures. Quantitative substitution of 2-(2',4',6'-trichlorophenoxy)2H-azepine derivatives, formed in moderate yield from the respective 3H-azepine and NBS in the presence of 2,4,6-trichlorophenol (TCP), by various nucleophiles gave the corresponding 2-substituted 2H-azepine. Among these nucleophiles were alkanethiol and alkylamine that are not tolerated in the reaction of 3H-azepine and NBS.

DOI： 10.1021/jo0500232

Synthesis of a delocalized azepinium ion and investigation of its electrophilic character 招待

K Satake, Y Kubota, CEJ Cordonier, H Okamoto, M Kimura

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION 43 ( 6 ) 736 - 738 2004年

Nucleophilic reactions of 5-tert-butyl-2-methoxy-3H-azepine with alkoxides and alkyllithium reagents 査読

Y Kubota, K Satake, R Ikui, H Okamoto, N Kimura

BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 76 ( 4 ) 805 - 811 2003年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：CHEMICAL SOC JAPAN

The reaction of 5-tert-butyl-2-methoxy-3H-azepine (2a) with sodium alkoxides gave 2-alkoxy-3H-azepine derivatives 3-6 by nucleophilic transetherification. The treatment of 2a with tert-butyllithium also yielded 2,5-di-tert-butyl-3H-azepine (7): however, the reaction of 2a and methyllithium gave the expected 5-tert-butyl-2-methyl-3H-azepine (8) along with unexpected 5-tert-butyl-2,2-dimethyl-2,3-dihydro-1H-azepine (9). but also 5,5'-di(tert-butyl)-2,2'-methylenedi(3H-azepine) (11), the structure of which was found to be tautomerized 5-tert-butyl-2-(5-tert-butyl-2,3-dihydro-1H-azepine-2-ylidenemethyl)-3H-azepine (12). The energy profile for the observed tautomerization is discussed based on ab initio DFT calculations and kinetic measurements.

DOI： 10.1246/bcsj.76.805

Photochemistry of N-isopropoxy-substituted 2(1H)-pyridone and 4-p-tolylthiazole-2(3H)-thione: Alkoxyl-radical release (spin-trapping, EPR, and transient spectroscopy) and its significance in the photooxidative induction of DNA strand breaks 査読

W Adam, J Hartung, H Okamoto, S Marquardt, WM Nau, U Pischel, CR Saha-Moller, K Spehar

JOURNAL OF ORGANIC CHEMISTRY 67 ( 17 ) 6041 - 6049 2002年8月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER CHEMICAL SOC

UVA-irradiation of the photo-Fenton reagents N-isopropoxypyridone 2b and N-isopropoxythiazole-2(3H)-thione 3b releases radicals which induce strand breaks. Transient spectroscopy establishes N-O bond scission [Phi(N-O) = (75 8)% for 2b and (65 7)% 3b] as the dominating primary photochemical process to afford the DNA-damaging radicals. Product studies and laser-flash experiments reveal that the thiazolethione 3b leads primarily to the disulfide 5, from which through C-S bond breakage, the bithiazyl 6, the thiazole 7, and the isothiocyanate 8 are derived. Upon irradiation of pyridone 2b (300 nm) in aqueous media, a mixture of isopropoxyl and 2-hydroxyprop-2-yl radicals is formed, as confirmed by trapping with 5,5-dimethyl-1-pyrroline N-oxide (DMPO) and EPR spectroscopy. In contrast, the photolysis of the thiazolethione 3b (350 nm) affords exclusively the DMPO adducts of the isopropoxyl radicals. Control experiments disclose that the thiazolethione-derived photoproduct disulfide 5, or the intermediary thiyl radicals B, scavenge the carbon-centered 2-hydroxyprop-2-yl radicals, which are generated from the isopropoxyl radicals by hydrogen shift. With supercoiled pBR 322 DNA in a 60:40 mixture of H2O-MeCN, the pyridone 2b and the thiazolethione 3b display moderate strand-break activity (17% open-circular DNA for 2b and 12% for 3b). In pure water, however, the pyridone 2b photoinduces substantially more DNA cleavage (32% open-circular DNA), which is attributed to the peroxyl radicals generated from the 2-hydroxyprop-2-yl radicals by oxygen trapping. The lower strand-break activity of the thiazolethione 3b derives presumably from isopropoxyl radicals, because only these are detected in the photolysis of this photo-Fenton reagent.

DOI： 10.1021/jo025856w

Nucleophilic substitution reaction of 5-t-butyl-2methoxy-3H-azepine with alkoxides and alkyllithium reagents: A formation of bis(5-t-butyl-3H-azepin-2-yl)methane having a vinamidine conjugation 査読

K Satake, Y Kubota, H Okamoto, M Kimura

HETEROCYCLES 57 ( 2 ) 223 - 228 2002年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD

Reaction of 5-t-butyl-2-methoxy-3H-azepine (2) with nuclephiles (alkoxides or t-butyllithium) gave respective substitution product at 2-position of the ring. Unexpectedly, when methyllithium was used as a nucleophile, bis(5-t-butyl-3H-azepin-2-yl)methane (7), the structure of which found to be tautomeric vinamidine (7a,b), was formed. Tautomerization between 7 and 7a,b was characterized spectroscopically and theoretically based on the levels of B3LYP/631G(d).

Photochromic properties of a 2,11-diaza[3,3]paracyclo(9,10)anthracenophane derivative having ethylenediamine host function on its bridge chains 査読

Hideki Okamoto, Yukari Nakatsu, Masaru Kimura, Kyosuke Satake

ITE Lett. Batter. New Technol. Med. 2002年

Preparation of a crown-ether-modified lophine peroxide as a guest-sensitive novel chemiluminophore and modulation of its chemiluminescence by metal cations 査読

H Okamoto, M Owari, M Kimura, K Satake

TETRAHEDRON LETTERS 42 ( 42 ) 7453 - 7455 2001年10月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD

A guest-sensitive chemiluminophore, a novel crown-ether-modified lophine peroxide 1. has been prepared. and its chemiluminescent behavior has been investigated in the presence of alkaline and alkaline earth metal cations. In the presence of Na+, the lambda (max) of the chemiluminescence of peroxide 1 was blue-shifted (505 nm) compared to the case without a metal cation (566 nm). The chemiluminescent intensity was enhanced by addition of Na+ while that of Mg2+ decreased the intensity. (C) 2001 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S0040-4039(01)01572-6

N-Hydroxy-4-(4-chlorophenyl)thiazole-2(3H)-thione as a photochemical hydroxyl-radical source: photochemistry and oxidative damage of DNA (strand breaks) and 2’-deoxyguanosine (8-oxodG formation) 査読

Waldemar Adam, Jens Hartung, Hideki Okamoto, Chantu Saha-M&ouml, ller, Kristina Spehar

Photochem. Photobiol. 72 ( 5 ) 619 - 624 2000年11月

Sensitized irradiation of anthracene-benzene biplanemers: Formation of adducts of a benzvalene or a Dewar benzene with anthracene 査読

Masaru Kimura, Hideki Okamoto, Zhi Zhi Hu, Setsuo Kashino

ITE Lett. Batter. New Technol. Med. 2000年

Circular polarization of photochemiluminescence from the photoisomer of a conformationally fixed 2,11-diaza[3.3](9,10)anthracenoparacyclophane derivative 査読

Hideki Okamoto, Harry P. J. M. Dekkers, Kyosuke Satake, Masaru Kimura

Chemical Communications ( 9 ) 1049 - 1050 1998年5月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Royal Society of Chemistry

The conformation of 2,11-diaza[3.3](9,10)anthracenoparacyclophane 1, which underwent photointerconversion with isomer 2, was fixed with the aid of a chiral camphanic auxiliary to have molecular chirality, and the photochemiluminescence from the modified 2a was circularly polarized reflecting the chirality of the emitting state.

DOI： 10.1039/a801296b

Synthesis and characterization of 2-methoxy-2H-azepines: The first isolation of 2-azanorcaradiene, the valence isomer of 3H-azepine

Kyosuke Satake, Yuko Tawada, Hideki Okamoto, Masaru Kimura

Journal of the Chemical Society - Perkin Transactions 1 ( 14 ) 2015 - 2017 1997年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Royal Society of Chemistry

The selective formation of 2-methoxy-2H-azepine from 3H-azepines, via a likely azatropylium cation, is reported
the first isolation of 2-azanorcaradiene, which is considered to be the valence isomer of 3H-azepine, is also described.

DOI： 10.1039/a703709k

Adiabatic photocycloreversion of bridged benzene-anthracene biplanemers: Controlling of the efficiency of the excited product formation by auxiliary substituents on the side-chains 査読

Hideki Okamoto, Kyosuke Satake, Masaru Kimura

Chemistry Letters ( 9 ) 873 - 874 1997年

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Chemical Society of Japan

The efficiency for excited product formation in the adiabatic photocycloreversion of bridged biplanemer 1 was controlled by the size of its side-chain substituents which changed the interchromophore distance in the photoproduct 2.

DOI： 10.1246/cl.1997.873

Rearrangement of bicyclo[2.2.2]octa-2,5-diene and bicyclo[3.2.2]nona-6,8-diene under the conditions of bromination 査読

Kyosuke Satake, Kazuyuki Hikasa, Hajime Itoh, Hideki Okamoto, Masaru Kimura, Shiro Morosawa

Bulletin of the Chemical Society of Japan 69 ( 2 ) 453 - 457 1996年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Chemical Society of Japan

A reaction of electrophilic bromination of norbornadiene homologs such as bicyclo[2.2.2]octa-2,5-diene (4) and bicyclo[3.2.2]nona-6,8-diene (7) with bromine gave hitherto unknown skeleton rearranged dibromides. The rearrangement may proceed via a bromonium cation of starting diene to give bicyclo[3.2.1]octene or bicyclo[3.3.1]nonene skeleton in respective cases. The observed rearrangement reactions are also confirmed in 6,7-bis(methoxycarbonyl) derivatives of bicyclodiene 7 under similar conditions.

DOI： 10.1246/bcsj.69.453

A new ring contraction rearrangement of 2,5-and 3,6-di-tert-butyl-3H-azepines to pyridine derivatives 査読

Kyosuke Satake, Koichi Takaoka, Michiaki Hashimoto, Hideki Okamoto, Masaru Kimura, Shiro Morosawa

Chemistry Letters ( 12 ) 1129 - 1130 1996年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Chemical Society of Japan

A new ring contraction reaction giving pyridine derivatives from 3,6-and 2,5-di-tert-butyl-3H-azepines was observed by a successive treatment with bromine and aqueous K2CD3. A plausible mechanism via azatropilium cation for the rearrangement was discussed based on the product's distribution from respective 3H-azepines.

DOI： 10.1246/cl.1996.1129

Characterization of a Longicyclic (2,2,2,2) Conjugated π System in 1,4-Difluorobenzene-Naphthalene Biplanemer

OKAMOTO Hideki, SATAKE Kyosuke, KIMURA Masaru

Bulletin of the Chemical Society of Japan 68 ( 12 ) 3557 - 3562 1995年12月

記述言語：英語出版者・発行元：The Chemical Society of Japan

The electronic absorption spectrum of a 1,4-difluorobenzene–naphthalene biplanemer 1 exhibited a characteristic absorption band around 290 nm. This was attributable to intramolecular charge transfer interaction between the longicyclic conjugated π system and the benzene chromophore. The oxidation potential of 1 was 1.70 V (vs. Ag/AgCl), which was lower than those of the related compounds in which one of the double bonds of 1 was hydrogenated. Thermally, the biplanemer 1 underwent facile Cope rearrangement, followed by dehydrofluorination, to give 1-(4-fluorophenyl)naphthalene and 2-(3-fluorophenyl)naphthalene.

DOI： 10.1246/bcsj.68.3557

Demethoxycarbonylation of methyl 2,5- and methyl 3,6-dialkyl-1H-azepine-1 carboxylates: Formation and characterization of 2H-, 3H- and 4H-azepines

Kyosuke Satake, Ryoichi Okuda, Michiaki Hashimoto, Yasusi Fujiwara, Hideki Okamoto, Masaru Kimura, Shiro Morosawa

Journal of the Chemical Society, Perkin Transactions 1 ( 13 ) 1753 - 1757 1994年

記述言語：英語掲載種別：研究論文（学術雑誌）

Demethoxycarbonylation of methyl 2,5-di-tert-butyl-1H-azepine-1-carboxylate using 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) gave 3H-azepines. Under similar conditions, methyl 3,6-ditert-butyl-1H-azepine-1-carboxylate gave not only the 3H-azepine but also the isomerized 2H- and 4H-azepines. Application of the reaction to dimethyl and diisopropyl substituted 1H-azepines showed that bulky alkyl group substitution stabilizes the seven-membered azatriene system. The thermal behaviour of the di-tert-butyl substituted azepines is discussed.

DOI： 10.1039/p19940001753

Synthesis and Adiabatic Photochemistry of a 1,4-Difluorobenzene-Naphthalene Biplanemer. 査読

Okamoto Hideki, Kimura Masaru, Satake Kyosuke, Morosawa Shiro

Bulletin of the Chemical Society of Japan 66 ( 8 ) 2436 - 2439 1993年

担当区分：筆頭著者記述言語：英語出版者・発行元：The Chemical Society of Japan

A naphtalene-1,4-difluorobenzene biplanemer 1a has been prepared through the electrolytic oxidative didecarboxylation. The direct irradiation of 1a gave 1,4-difluorobenzene and excited naphthalene in both a singlet state (Φ_f = 0.098) and a triplet state (Φ_p = 0.029) at 77 K in EPA. In the triplet-sensitized reaction, the biplanemer 1a underwent intramolecular [2π+2π] cycloaddition to give a cage compound instead of the formation of the triplet naphthalene.

DOI： 10.1246/bcsj.66.2436

　前のページ - 次のページ　

1
2
3
4
5
6