巻号一覧
65 巻, 7 号
選択された号の論文の10件中1～10を表示しています
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武内 亮, 毛塚 智子2007 年 65 巻 7 号 p. 652-664
発行日: 2007/07/01
公開日: 2010/10/20
ジャーナル フリーTransition metal complexes play an important role in modern organic synthesis, because they can realize useful transformations that would be either difficult or impossible by conventional organic chemistry. Organic synthesis with iridium was far behind that with rhodium, ruthenium and palladium in the early 1990 s. However, many useful reactions catalyzed by iridium have been reported today. This review focuses on enantioselective hydrogenation of unfunctionalized alkenes, allylic substitution, cycloaddition, cycloisomerization, carbonylation and aldol reaction.抄録全体を表示PDF形式でダウンロード (1892K) -
好光 健彦, 長岡 博人, 田中 徹明2007 年 65 巻 7 号 p. 665-676
発行日: 2007/07/01
公開日: 2010/10/20
ジャーナル フリーReactive free radicals have wide applications in organic synthesis due to their remarkable chemical properties that allow useful molecular transformations. The present review covers the author's recent studies on the utilization of radical species in chemical synthesis of organic molecules : The first topic deals with two types of alkoxyl radicals (primary or tertiary) that selectively undergo dehydrogenation or β-scission to give rise to the key structural elements of (-) -CP-263, 114, a ras-farnesyl transferase inhibitor. The second part of this review describes the development of new carbon-carbon bond forming reactions that proceed via the direct and selective abstraction of the hydrogen from the sp3C-H bond adjacent to oxygen or nitrogen. In this radical C-H bond transformation, triethylborane serves not only as a source of hydrogen abstractor but as an alkoxyl radical scavenger that enables the irreversible addition of carbon radicals to carbon-oxygen double bonds.抄録全体を表示PDF形式でダウンロード (1955K) -
河合 英敏2007 年 65 巻 7 号 p. 677-687
発行日: 2007/07/01
公開日: 2010/10/20
ジャーナル フリーThe cooperativity in amide hydrogen-bonds plays an important role in stabilizing folded structures of protein and realizing allosterism in nature. We prepared hydrindacene-based exoditopic receptors with two amide groups as a cooperative binding site. These exoditopic receptor exhibit a positive homotropic allosteric binding process toward benzenediols and forms 1 : 2 complexes with resorcinols, and catechol with K2/K1=3-33. Both of the entropy and the enthalpy terms are operating in this allosteric system; the crystallographic studies provide the first clear evidence that the cooperativity in amide hydrogen bonding by polarization leads to the positive homotropic allosteric binding property. Furthermore, 1 : 1 complexation of the receptor with a dopamine salt as an allosteric effector significantly inhibits the binding with resorcinols. In the present system, we revealed that the allosteric modulation by the effector molecule leads to the cooperative release of the bound guests.抄録全体を表示PDF形式でダウンロード (2078K) -
笹森 貴裕, 時任 宣博2007 年 65 巻 7 号 p. 688-699
発行日: 2007/07/01
公開日: 2010/10/20
ジャーナル フリーThere has been much interest in the synthesis and properties of doubly bonded systems between heavier group 15 elements, heavier analogues of azo-compounds (dipnictenes), from the standpoints of fundamental and material chemistry since the first synthesis of a kinetically stabilized diphosphene, MesP = PMes (Mes=2, 4, 6-tri-t-butylphenyl), reported by Yoshifuji and his coworkers. We have also succeeded in the synthesis of the first stable distibene (RSb = SbR) and dibismuthene (RBi=BiR) by taking advantage of efficient steric protection groups, 2, 4, 6-tris [bis (trimethylsilyl) methyl] phenyl (Tbt) and 2, 6-bis [bis (trimethylsilyl) methyl] -4- [tris (trimethylsilyl) methyl] phenyl group (Bbt), and revealed their properties systematically. Nowadays, several types of synthetic methods have been established for dipnictenes, and double-bond compounds with various combination of heavier group 15 elements have been synthesized and isolated by utilizing kinetic stabilization. In this paper, we report the synthetic studies on the kinetically stabilized dipnictenes.抄録全体を表示PDF形式でダウンロード (2074K) -
伊坂 雅彦2007 年 65 巻 7 号 p. 700-708
発行日: 2007/07/01
公開日: 2010/10/20
ジャーナル フリーSeveral insect pathogenic fungi, including the Chinese medicine Cordyceps sinensis, have been utilized as folk medicines or healthy foods, and some others are important bioinsecticides. However, most of insect pathogenic fungi, naturally rare species, remain chemically unexplored. We have been investigating the secondary metabolites of insect fungi that were collected in Thailand. The studies led to the isolation and structure elucidation of a number of new compounds with diverse chemical structures. In particular, cordyanhydrides and vertihemiptellides possess hitherto unknown skeletons, whereas cordypyridones and hirsutellones exhibit significant antimalarial and antitubercular activities, respectively. These results demonstrate that insect pathogenic fungi are potent sources of novel bioactive compounds.抄録全体を表示PDF形式でダウンロード (1597K) -
藤本 健造2007 年 65 巻 7 号 p. 709-714
発行日: 2007/07/01
公開日: 2010/10/20
ジャーナル フリーDNA engineering, the basis of modern protein engineering, has been developed since the 1960s with many discoveries, including those of various restriction enzymes and polymerases, and a number of Nobel laureates for their contributions to, for example, the PCR method or DNA sequencing method. The existing biotechnology is thus essential to basic researches in the present DNA analysis or biochemistry. While many methods for enzymatic and chemical ligation of DNA fragment via a native phosphodiester bond or non-native linkages have been demonstrated, there are only a few methods for photoinduced non-enzymatic chemical ligation. The merit of the photochemical ligation avoiding the need for additional reagent is obvious. Furthermore, their actions are controllable within space and time by the choice of proper irradiation methods. The photoligation methods can be used as a tool for DNA engineering and nanotechnology, and as photoregulated diagnostic and therapeutic agents. Thcrcforc, the targct in my research is the development about phototriggered DNA manipulation via intelligent nucleic acids toward for the next generation DNA manipulation.抄録全体を表示PDF形式でダウンロード (748K) -
端早田 隆2007 年 65 巻 7 号 p. 715-716
発行日: 2007/07/01
公開日: 2010/10/20
ジャーナル フリーThis short review describes the recent development on β-mannosidic bond formation. Though the formation of β-mannoside is rather difficult in chemical synthesis, following two useful representative methods are reported; 1) introducing an acetal moiety as an acceptor on a donor as the stereocontroling element for intramolecular β-mannosylation; 2) using a donor having cyclic acetal protecting group at O-4, 6 position. As for the later, it was reported that the introduction of propagyl group at O-2 position improved β-selectivity even if a donor having steric protecting group at O-3 position was employed. Catalytic and β-selective mannosylation is also noted.抄録全体を表示PDF形式でダウンロード (362K) -
-Yale大学Hartwig研究室にて-宇都宮 賢2007 年 65 巻 7 号 p. 717-723
発行日: 2007/07/01
公開日: 2010/10/20
ジャーナル フリーDiscovery and understanding of late transition metal-catalyzed intermolecular, hydroamination of vinylarenes with various kinds of alkylamines have been performed. Catalysts having palladium, rhodium, and ruthenium as metal center gave hydroamination products with excellent regio selectivity based on the metal feature. In this paper, catalyst development, reaction scope and mechanistic study are briefly summarized for various hydroamination. Palladium catalyst gave Markovnikov product of styrene derivatives with cyclic and acyclic secondary alkylamines. In contrast, rhodium and ruthenium performed anti-Markovnikov hydroamination of vinylarenes to produce various kinds of amines with or without enamine as side product. Finally, catalytic additions of OH bonds of phenols and carboxylic acids across conjugated dienes were achieved by simple palladium catalyst.抄録全体を表示PDF形式でダウンロード (1261K) -
佐藤 睦, 大野 桂二2007 年 65 巻 7 号 p. 724-726
発行日: 2007/07/01
公開日: 2010/10/20
ジャーナル フリーPDF形式でダウンロード (359K) -
好光 健彦, 河合 英敏, 笹森 貴裕, 藤本 健造2007 年 65 巻 7 号 p. 727
発行日: 2007/07/01
公開日: 2010/10/20
ジャーナル フリーPDF形式でダウンロード (203K)
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