巻号一覧
53 巻, 10 号
選択された号の論文の13件中1～13を表示しています
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大城 芳樹1995 年 53 巻 10 号 p. 846-857
発行日: 1995年
公開日: 2009/11/16
ジャーナル フリーPolyfunctionalized heterocycles have been important key compounds in the fields of functional and biologically active substances. From this point of view, we have developed novel synthetic methods for polyfunctionalized heterocycles according to the following approaches, 1) polar cycloadditions of three-membered heterocycles and azadienes, 2) functionalization of pyridine nucleus leading to condensed pyridine derivatives, 3) molecular design of novel electron transfer catalysts based on chemical simulation of coenzyme PQQ and TTQ, 4) application of heteroatom compounds as heterocyclic building blocks.抄録全体を表示PDF形式でダウンロード (1328K) -
千田 憲孝, 小川 誠一郎1995 年 53 巻 10 号 p. 858-868
発行日: 1995年
公開日: 2009/11/16
ジャーナル フリーPreparation of optically active, highly functionalized carbocycles is an important issue in recent synthetic organic chemistry. Ferrier's carbocyclization reaction, which provides optically pure cyclohexanones from aldohexoses, is one of the most efficient procedures for this purpose. Chiral and highly oxygenated cyclohexanes obtained by this reaction are potentially versatile chiral building blocks in natural product synthesis. In this article, the development of catalytic Ferrier's carbocyclization reaction with mercury (II) trifluoroacetate, and total syntheses of natural products containing cyclohexane units (hygromycin A, lycoricidine, and mesembranol) starting from aldohexoses using this reaction as the key steps are described The methodology described in this article extends the usefulness of carbohydrates as chiral building blocks to the synthesis of natural products possessing cyclohexane rings in optically active forms.抄録全体を表示PDF形式でダウンロード (1529K) -
小川 昭弥1995 年 53 巻 10 号 p. 869-880
発行日: 1995年
公開日: 2010/01/28
ジャーナル フリーRadical addition of organic chalcogen compounds to carbon-carbon unsaturated bonds is investigated precisely. Upon irradiation with UV or visible light, organic dichalcogenides such as disulfides, diselenides, and ditellurides undergo homolysis easily to generate the corresponding chalcogen-centered radicals. Nevertheless, only very limited examples of the radical addition of organic dichalcogenides to unsaturated bonds are known hitherto. This is probably because the lower capturing ability of disulfides (in the case of disulfides) and the lower reactivity of seleno and telluro radicals toward unsaturated bonds (in the case of diselenides and ditellurides) contribute to inefficiency of the desired radical addition reactions. We have revealed that novel mixed systems of organic dichalcogenides, e.g., (PhS)2- (PhSe)2 and (PhS)2- (PhTe)2, successfully cause the efficient radical addition to a wide variety of carbon-carbon unsaturated compounds such as alkenes, acetylenes, dienes, and allenes, etc. The procedure disclosed provides highly selective synthesis of a series of functionalized chalcogen compounds.抄録全体を表示PDF形式でダウンロード (1450K) -
横松 力, 山岸 丈洋, 渋谷 皓1995 年 53 巻 10 号 p. 881-892
発行日: 1995年
公開日: 2009/11/16
ジャーナル フリーIn recent years there has been a broadly expanding interest in the synthesis of α-heteroatom-substituted phosphonates such as those bearing amino, hydroxy, and fluoro substituents. This interest has resulted from their potential utilities as mimics for α-amino carboxylates and biological phosphates in the biological processes. This review is focussed on the recent development for the efficient synthesis of these α-heteroatom-substituted phosphonates. The examples cited in this review are divided in six distinct types of methods : (a) C-P bond formation, (b) C-C bond formation, (c) heterofunctionalization, (d) conversion of prochiral phosphonates, (e) resolution of α-substituted phosphonates, (f) functional conversion of α-substituted phosphonates.抄録全体を表示PDF形式でダウンロード (1529K) -
北村 二雄1995 年 53 巻 10 号 p. 893-905
発行日: 1995年
公開日: 2010/01/28
ジャーナル フリーHighly reactive hypervalent organoiodine reagents were prepared from iodosylbenzene (PhIO) or iodobenzene diacetate [PhIO(OAc)2] by using the activating agents such trifluoromethanesulfonic acid or the anhydride. The reagents [PhIO-TfOH] and [PhI(OAc)2-2 TfOH] showed a high reactivity toward unsaturated substrates : aromatics, alkenes, and alkynes. Reaction of PhIO with double the molar quantity of TfOH gave a (p-phenylene) bisiodine (III) reagent, 1-[(hydroxy)(trifyloxy)iodo]-4-[(phenyl)(trifyloxy)iodo] benzene, which also indicated an excellent reactivity toward unsaturated substrates. ο-Iodosylbenzoic acid was activated by TfOH to afford a reactive iodine (III) reagent. The high reactivity of the present organoiodine (III) reagents was useful in organic synthesis, specially preparation of functionalized iodonium salts. The prepared alkynyliodonium salts and [ο-(trimethylsilyl)phenyl] iodonium salts were found to be especially accessible to organic synthesis.抄録全体を表示PDF形式でダウンロード (1327K) -
侯 召民, 若槻 康雄1995 年 53 巻 10 号 p. 906-916
発行日: 1995年
公開日: 2009/11/16
ジャーナル フリーThis account describes our recent studies on the reactions of diary! ketones with low valent lanthanides, and on the hexamethylphosphoramide (HMPA) -coordinated LnI2 (Ln = Sm, Yb) complexes. Emphases are put on clarification of the relation between structures and reactivities of the complexes. The following issues are mainly addressed. 1) Isolation and structural characterization of samarium and ytterbium ketyl complexes. 2) Solvent (ligand) effects on the reactivity of the ketyl complexes. 3) Isolation and structural characterization of an ytterbium benzophnone dianion complex. 4) Protonation at the aromatic ring vs. at the carbonyl group of samarium and ytterbium diaryl ketone dianion species by phenols. 5) Isolation and structural characterization of three types of HMPA-coordinated LnI2 (Ln = Sm, Yb) complexes and evaluation of the HMPA effects observed in SmI2/HMPA mediated reactions.抄録全体を表示PDF形式でダウンロード (1355K) -
森 謙治1995 年 53 巻 10 号 p. 917-918
発行日: 1995年
公開日: 2009/11/16
ジャーナル フリーPDF形式でダウンロード (315K) -
四方田 隆1995 年 53 巻 10 号 p. 918-919
発行日: 1995年
公開日: 2009/11/16
ジャーナル フリーPDF形式でダウンロード (324K) -
加藤 博1995 年 53 巻 10 号 p. 919-920
発行日: 1995年
公開日: 2009/11/16
ジャーナル フリーPDF形式でダウンロード (322K) -
田坂 興亜1995 年 53 巻 10 号 p. 920-921
発行日: 1995年
公開日: 2009/11/16
ジャーナル フリーPDF形式でダウンロード (316K) -
畠中 康夫1995 年 53 巻 10 号 p. 921-922
発行日: 1995年
公開日: 2009/11/16
ジャーナル フリーPDF形式でダウンロード (307K) -
常石 敬一1995 年 53 巻 10 号 p. 922-923
発行日: 1995年
公開日: 2009/11/16
ジャーナル フリーPDF形式でダウンロード (270K) -
大城 芳樹, 千田 憲孝, 若槻 康雄1995 年 53 巻 10 号 p. 924
発行日: 1995年
公開日: 2009/11/16
ジャーナル フリーPDF形式でダウンロード (162K)
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