巻号一覧
56 巻, 4 号
選択された号の論文の8件中1～8を表示しています
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冨田 育義, 高木 幸治, 遠藤 剛1998 年 56 巻 4 号 p. 260-267
発行日: 1998/04/01
公開日: 2009/11/16
ジャーナル フリーThis article describes our recent works on the living coordination polymerization of allene derivatives by allylnickel catalysts. The polymerization of alkoxyallenes by allylnickel catalysts proceeds via a living process to give polymers with predictable molecular weights and narrow molecular weight distributions in excellent yields. The polymerization was carried out with allylnickel complexes bearing various ligands to figure out the clear effect on the polymer structures and the polymerization behavior. Similarly, allene derivatives bearing various substituents such as phenylallene, alkylallenes, allenylsulfide, allenylpyrrolidone, allenyloxazolidone, esters of allenic acid, and macromonomers bearing allenyloxy end groups undertake the living polymerization. Macromolecular designs based on the living polymerization of allene derivatives (e.g., block copolymerizations) are also described.抄録全体を表示PDF形式でダウンロード (952K) -
不斉の場無しでの不斉の出現 (その1)小島 秀子, 松浦 輝男1998 年 56 巻 4 号 p. 268-279
発行日: 1998/04/01
公開日: 2009/11/16
ジャーナル フリーChiral crystallization of optically inactive (achiral) compounds such as benzophenone, phenol, phenanthrene, etc. has not been a commonly known phenomenon in organic chemistry. These compounds are known to crystallize to chiral crystals from their solutions. This review deals with this phenomenon, describing (1) what is chiral crystallization and how to find organic compounds undergoing chiral crystallization, (2) the preparation of chiral crystals from achiral organic compounds, (3) the characterization of chiral crystals, (4) the crystal structure of chiral crystals and the factors of the generation of chirality, (5) the chiral crystallization of two-component molecular compounds, (6) absolute asymmetric synthesis utilizing chiral crystallization, (7) other applications of chiral crystallization. Part 1 describes chapters (1), (2), (3), and (4).抄録全体を表示PDF形式でダウンロード (1637K) -
芝田 育也, 馬場 章夫1998 年 56 巻 4 号 p. 280-290
発行日: 1998/04/01
公開日: 2009/11/16
ジャーナル フリーNovel types of tin hydrides were developed by the introduction of a halogen substituent or a ligand on the tin atom. These modified tin hydrides achieved chemoselective reduction between carbonyl groups and other functionalities such as organic halides, epoxides, imines and enones. In the reaction with epoxy ketones, two types of tin hydrides Bu3SnH-Bu4NF and Bu2SnFH-HMPA systems reduced only the carbonyl moieties with high syn- and anti-selectivities, respectively. Whereas, when Bu2SnIH -HMPA was used, the reduction of epoxide groups took place to give 3-hydroxy ketone, where the carbonyl groups were tolerated. The high nucleophilicity of Sn-I bond toward epoxides is responsible for the selectivity. Tin chloride hydride complex, Bu2SnClH-HMPA was revealed to reduce imines over carbonyl groups. In the reduction of conjugated enone, Bu2SnFH afforded 1, 2-reduction predominantly to give allylic alcohol. On the other hand, Bu2SnIH promoted the selective 1, 4-reduction of enones even in the presence of aldehydes. When a mixture of an enone and PhCHO was treated with Bu2SnIH, the first resulting tin enolate subsequently reacted with co-existent PhCHO to give an aldol product.抄録全体を表示PDF形式でダウンロード (1357K) -
鈴木 孝治1998 年 56 巻 4 号 p. 291-302
発行日: 1998/04/01
公開日: 2010/01/28
ジャーナル フリーFor developing high performance chemical ion sensors, the optimal design of ionophores, which are used as the ion sensing component for the sensor, is one of the most important areas of investigation.
Here I report the general concept and knowledge of ionophore chemistry through a discussion of the design and synthesis of ionophores for alkali metal ions, alkaline earth metal ions and the ammonium ion.
There are several important factors when designing ionophores that can be divided into two groups ; one is 'binding nature' which offers the ion binding atoms or groups of the ionophore itself, and the other is the 'stereospecific factor' which concerns the configuration of the ion-ionophore complex.
Based on several ionophore molecular models, which are proposed with the consideration of these two factors, highly ion-selective ionophores for Li+, Na+ (alkali metal ions), Mg2+, Ca2+ (alkaline earth metal ions) and NH4+ were successfully developed. The stories for developing these ionophores were discussed with the expected and unexpected results on the structural ion-selectivity features of more than 90 kinds of synthesized ionophores.抄録全体を表示PDF形式でダウンロード (1892K) -
山田 眞二1998 年 56 巻 4 号 p. 303-311
発行日: 1998/04/01
公開日: 2009/11/16
ジャーナル フリーWe have found amides of which C (O) -N bonds are extremely twisted. The structures were elucidated by 13C NMR, IR and UV spectroscopies, and X-ray analysis. Since the twisted amides are highly reactive compared to the planar ones, these were used for the acylation of hydroxy groups under neutral conditions. In the reaction of diols containing primary and secondary hydroxy groups with the amides, the primary one was selectively acylated. For diols containing alcoholic and phenolic hydroxy groups, the acylation selectively gave the corresponding alkyl esters. Furthermore, axially chiral twisted amides served as asymmetric acylating agents for sec-alcohols. We also investigated the effects of the C (O) -N bond rotation of the amides on the 13C, 15N, and 17O NMR chemical shifts, and IR carbonyl absorption. As the twist angle increased, the δ13C, δ17O and vC=o values increased, whereas, the δ15N value decreased. It was also found that the 13C (O) -15N coupling constants depend on the twist angles.
The 1JC (O) , N value decreased with increasing twist angles.抄録全体を表示PDF形式でダウンロード (1074K) -
原 正治, 米田 徳彦1998 年 56 巻 4 号 p. 312-319
発行日: 1998/04/01
公開日: 2009/11/16
ジャーナル フリーRecently, Et3N-nHF complexes have been used for a variety of fluorination reactions instead of hazardous anhydrous HF. This review summarizes the recent progress in the fluorination reaction using Et3N-nHF complexes except Et3N-3HF. Et3N-HF and Et3N-2 HF have been used as nucleophilic fluorinating reagents in the SN2 type ring opening of terminal oxiranes and substitution with alkyl halides. On the other hand, Et3N-5 HF and Et3N-6 HF complexes, which are slightly more acidic than Et3N-3HF, have been used as 1) an electrolyte in electrochemical fluorination reactions 2) a hydrofluorination reagent of alkenes and alkenals and 3) a co-reagent of iodotoluene difluoride in the oxidative fluorination of β-dicarbonyl compounds, alkenes, and alkynes.抄録全体を表示PDF形式でダウンロード (865K) -
杉本 八郎1998 年 56 巻 4 号 p. 320-327
発行日: 1998/04/01
公開日: 2009/11/16
ジャーナル フリーPDF形式でダウンロード (1078K) -
冨田 育義, 鈴木 孝治, 山田 眞二, 米田 徳彦1998 年 56 巻 4 号 p. 328
発行日: 1998/04/01
公開日: 2009/11/16
ジャーナル フリーPDF形式でダウンロード (160K)
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