巻号一覧
60 巻, 12 号
選択された号の論文の9件中1～9を表示しています
- |<
- <
- 1
- >
- >|
-
平野 雅文, 小峰 伸之, 小宮 三四郎2002 年 60 巻 12 号 p. 1148-1157
発行日: 2002/12/01
公開日: 2009/11/13
ジャーナル フリーReactions of zero-valent ruthenium complex [Ru (η4-1, 5-COD) (η6-1, 3, 5-COT)] (1) (COD = cyclooctadiene, COT = cyclooctatriene) with a series of monodentate tertiary phosphines cause selective displacement of the COD ligand to give Ru (COT) complexes, in which the COT ligand coordinates to the Ru either by η4 or η1 : η3 fashion [[Ru (1-4-η4-1, 3, 5-COT) L3] {L = PEt3 (2a), PBu3 (2b), PEt2Ph (2c)}, [Ru (6-η1 : 1-3-η3-COT) L3] {L = PMe3 (3a), PMe2Ph (3b)}]. The highly reduced zero-valent complex 2a-c, shows higher activity toward C-O bond cleavage reaction of alkenyl carboxylate than 1 and 1/phosphine system. Complex 1/phosphine system shows high activity toward versatile bond cleavage reactions such as C-O bond of vinylic and allylic carboxylates or ethers, C-S bond of sulfide or thiophenes, and sp3 C-H bond of ortho substituted phenols or carboxylic acids. Oxidative addition of C-H bond in active methylene compounds takes place to give hydrido (enolato) ruthenium (II) complexes, where zwitterionic structure of the enolato ligand derived from cyanoesters enhances their nucleophilic character to act as an active intermediate in Murahashi aldol and Michael reactions catalyzed by low-valent ruthenium complex.抄録全体を表示PDF形式でダウンロード (1656K) -
伊藤 彰近, 正木 幸雄2002 年 60 巻 12 号 p. 1158-1167
発行日: 2002/12/01
公開日: 2009/11/13
ジャーナル フリーTi-HMS, MCM-41 and FSM-16, which are typical hexagonal mesoporous silicas, were attempted to use as a promoter for organic synthesis. Ti-HMS, which possesses Lewis acid sites due to Ti-atom, was found to accelerate deprotection of benzyl groups, which is a typical protective group of hydroxyl group, selectively under hydrogenolytic conditions with palladium catalyst even in the presence of acid-sensitive functional groups such as silyl ether and acetal moieties in the molecule. MCM-41 proved to deprotect triethylsilyl (TES) group, which is another typical protective group of hydroxyl group, selectively and easily in the presence of t-butyldimethylsilyl (TBS) group. FSM-16 was found to accelerate several photo-reaction such as oxidative photodecarboxylation of α-hydroxy carboxylic acid, oxidation of arylmethylhalides and arylmethylalcohols, and oxidative cleavage of styrenes. Efficiency of these reactions was investigated concerning the solvent effect and activities of the promoters including common zeolites and ion-exchange resins.抄録全体を表示PDF形式でダウンロード (1697K) -
花本 猛士2002 年 60 巻 12 号 p. 1168-1178
発行日: 2002/12/01
公開日: 2009/11/13
ジャーナル フリーWe prepared and examined several versatile mono-fluorinated building blocks bearing an α-fluorovinyl moiety. Each compound has a variety of heteroatoms such as phosphorus, silicon, stannane, and sulfur. This review mainly consists of the following four parts. 1) (α-Fluorovinyl) phosphonium salts underwent Michael addition followed by Wittig olefination to give the corresponding monofluoroethylene compounds in good yields. 2) α-Fluorovinylation with carbonyl compounds was carried out using (α-fluorovinyl) methyldiphenylsilane in the presence of TBAF. 3) Cross-coupling reaction of the silane with aryl halides smoothly proceeded giving the corresponding α-fluorinated styrene derivatives. 4) Carbonylative cross-coupling reaction of (α-fluorovinyl)tributylstannane with aryl halides and aryl triflates proceeded to afford the corresponding α-fluorovinyl aryl ketones under a CO atmosphere. Finally, 1, 1-difluoroethylene as a key fluoride source was employed in order to prepare the above building blocks.抄録全体を表示PDF形式でダウンロード (1653K) -
岩瀬 礼子, 村上 章2002 年 60 巻 12 号 p. 1179-1189
発行日: 2002/12/01
公開日: 2009/11/13
ジャーナル フリーIn 1991 Nielsen et al. first described peptide nucleic acid (PNA), which is a DNA mimic with a pseudopeptide backbone composed of N-(2-aminoethyl) glycine units with the nucleobases attached to the glycine nitrogen via carbonyl methylene linkers. PNA is a very attractive molecule as a DNA mimic because it shows high biological stability with strong binding-affinity to complementary DNA and RNA. The limitations of PNA include low aqueous solubility, ambiguity in DNA binding orientation and poor membrane permeability. Various PNA derivatives were reported to improve physicochemical and biological properties of PNA. Chirality was introduced into the achiral PNA backbone to influence the selectivity in DNA binding orientation. PNA backbone was rigidified by introduction of ring structure to preorganize PNA for duplex formation. This review focuses on the chemistry and biological activity of PNA, and gives an overview of backbone modifications of PNA.抄録全体を表示PDF形式でダウンロード (1872K) -
西川 秀幸, 根来 雅之, 河田 憲, 岡崎 正樹2002 年 60 巻 12 号 p. 1190-1200
発行日: 2002/12/01
公開日: 2009/11/13
ジャーナル フリーA novel optically anisotropic film which consists of discotic liquid crystalline molecules (2, 3, 6, 7, 10, 11-triphenylenehexayl hexakis [4- (4-acryloyloxybutyloxy) benzoate] (THABB)) aligned and fixed in hybrid mode was invented. The discotic liquid crystalline molecules are polymerizable discotic nematic liquid crystalline triphenylene derivatives. The film is exceedingly useful for improvement in viewing angle of TN LCD.
In our study, ND (discotic nematic) phase was the most suitable liquid crystalline phase for preparation of the optically anisotropic film. ND phase was frequently shown by 2, 3, 6, 7, 10, 11-triphenylenehexayl hexakis (4-alkoxybenzoate) derivatives. Some modification of the alkoxy group brought about disappearance of ND phase. Introduction of an acryloyl group to the alkoxy group at the terminal position, however, did not caused disappearance of the ND phase.
Synthesis of THABB on a large scale included problems of purity in a few steps. Introduction of new synthetic methods and refining the reaction condition in the small scale case, however, has resulted in highly pure THABB producing process.抄録全体を表示PDF形式でダウンロード (2225K) -
池田 将, 竹内 正之, 新海 征治2002 年 60 巻 12 号 p. 1201-1209
発行日: 2002/12/01
公開日: 2009/11/13
ジャーナル フリーConstruction of nonlinear response systems is of importance for switching and amplification of guest affinity and selectivity. In nature the phenomena are ubiquitous, however, the methodology for the design of such artificial systems has not been developed so far. In nonlinear response systems, the guest binding information must be efficiently transmitted to the other binding sites through the positive homotropic allosteric interaction. Here, we show a new concept utilizing a molecular machinery approach to realize the nonlinear response. In our scheme, rotating modules are used for the allosteric interaction, where the guest binding information in a binding site is passed to the other binding sites in unison through “rotation”.
With this concept, we rationally designed a variety of double decker porphyrin host molecules as well as the other host molecules bearing rotational axle. These studies open up a new field for designing intelligent molecular machinery systems which can respond to outer stimuli.抄録全体を表示PDF形式でダウンロード (1723K) -
田中 早苗2002 年 60 巻 12 号 p. 1210-1214
発行日: 2002/12/01
公開日: 2009/11/13
ジャーナル フリーThe shape of dodecahedron is so symmetric that ancient Greak mathematicians and philosophers thought that dodecahedron is fundamental structure of universe.
Professor Sin'iti Kawai had another look from standpoint of organic chemistry. He thought that compounds of dodecahedron must be synthesized from C20H20 hydrocarbon. He gave it the name of dodecahedrane (DDH) and proposed the route of synthesis of this compound.
DDH was watched with interest chiefly in Europe and America after that. Bicyclo [3.3.0] octane derivatives (1958, Tanaka), triquinacene which had three cyclopentenes (1964, Woodward, 1967, T. T. Jacobson) and peristylane which had six cyclopentanes (1972, P. E. Eaton) were synthesized as intermediate compounds. C. A. Paquette completed the total synthesis of DDH (1983). Ring compounds such as fullerene, gas hydrate, etc. were synthesized later, and existence of DDH and its unit was confirmed in those compounds.抄録全体を表示PDF形式でダウンロード (784K) -
酒井 俊人2002 年 60 巻 12 号 p. 1215-1218
発行日: 2002/12/01
公開日: 2009/11/13
ジャーナル フリー表題の化合物, TEMPO (2, 2, 6, 6-Tetramethyl-1-piperidinyloxy, free radical) は, 酸化防止剤, 重合禁止剤, 保存安定剤等の用途もあるが, ここでは主に酸化剤と分子量分布調整剤としての利用法について述べたい.TEMPOは第1級アルコールを酸化してアルデヒドに変換する反応に用いられ, 特に第2級アルコールが共存する系においても, 選択的に第1級アルコールのみを酸化できることが特徴である.この場合, 第2級アルコールはほとんど影響を受けない.また, 不斉中心に隣接する第1級アルコールをアルデヒドに酸化する場合においても, TEMPOを使用する酸化反応系は条件がマイルドなこともあり, ラセミ化がほとんど起こらないことも特徴である.さらに, スチレンモノマーまたはスチレンモノマーを含有する混合モノマー系をラジカル重合させる時にTEMPOを共存させておくと, 分子量分布幅の狭いポリマーが得られる.抄録全体を表示PDF形式でダウンロード (452K) -
伊藤 彰近, 岩瀬 礼子, 西川 秀幸, 池田 将, 竹内 正之, 新海 征治2002 年 60 巻 12 号 p. 1219
発行日: 2002/12/01
公開日: 2009/11/13
ジャーナル フリーPDF形式でダウンロード (200K)
- |<
- <
- 1
- >
- >|