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Volume 62, Issue 8
Displaying 1-8 of 8 articles from this issue
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Shunji Ito, Noboru Morita, Takahiro Kubo2004 Volume 62 Issue 8 Pages 766-777
Published: August 01, 2004
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSStabilization of the ionic state and formation of polymethine dye with intense absorption in visible region by azulene skeleton are applied for the creation of novel polyelectrochromic materials. A new structural principle for the preparation of the polyelectrochromic system with high thermodynamic stability is proposed. The system is consisted with the polymethine dye containing the moieties of either one or two cyanine dyes as end groups. Multiple-color change was established by the use of azulene as a redox active chromophore on the principle of the cyanine-cyanine hybrid. The scope of the creation of novel polyelectrochromic materials taking full advantage of azulene skeleton and the new principle to design polyelectrochromic system is demonstrated by several examples.View full abstractDownload PDF (1785K) -
Hideaki Oikawa2004 Volume 62 Issue 8 Pages 778-789
Published: August 01, 2004
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSRecent studies on the enzyme catalyzing Diels-Alder reaction, “Diels-Alderase”, clearly demonstrated involvement of this synthetically useful reaction in the biosynthesis of natural products. This article describes natural Diels-Alder type cycloadducts, synthetic efforts on chemical feasibility of biosynthetic Diels-Alder reaction and brief history of studies on Diels-Alderase. In addition, reaction mechanisms of artificial and natural Diels-Alderase are discussed.View full abstractDownload PDF (2140K) -
Masaichi Saito, Michikazu Yoshioka2004 Volume 62 Issue 8 Pages 790-798
Published: August 01, 2004
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSThe synthesis, structures and physical and chemical properties of mono- and dianions of group 14 metalloles (1-metallacyclopentadiene), heavier congeners of the cyclopentadienyl anion, are described. The silole anion shows aromaticity with different extent by its substituent, while the germole anion does not show aromaticity. On the contrary, dianions of metalloles have a great extent of aromatic character owing to strong participation of divalent resonance forms. Theoretical calculation suggests that the coordination of lithium to the metallole dianions should promote their aromaticity. The synthesis and characterization of η5-silolyl and η5-germolyl metal complexes, analogs of ferrocene, are also described.View full abstractDownload PDF (1307K) -
Jun-ichi Hanna, Masahiro Funahashi2004 Volume 62 Issue 8 Pages 799-810
Published: August 01, 2004
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSIn these ten years, two separate groups including the author's discovered the electronic conduction in liquid crystals, whose electrical conduction had been believed to be ionic for a long time. Since then, we have synthesized model compounds and characterized their charge carrier transport properties in order to establish the scientific basis for their device application in the future. In this article, the updated understanding of electrical conduction in liquid crystals is reviewed in relation to the model materials synthesized. This demonstrates a high potential of liquid crystals as a new class of quality organic semiconductors, i.e., Self-organizing Molecular Semiconductor.View full abstractDownload PDF (2640K) -
Kazuhiro Kobayashi2004 Volume 62 Issue 8 Pages 811-820
Published: August 01, 2004
Released on J-STAGE: January 22, 2010
JOURNAL FREE ACCESSNew simple methods for the preparation of heterocycle-fused quinone derivatives based on tandem Michael addition-cyclization sequence between quinones and enamines (or imines) have been developed. The reaction of 2-hydroxy-1, 4-naphthoquinones with enamines, derived from ketones, afforded 2, 3-disubstituted naphtho [2, 3-b] furan-4, 9-diones. 1H-Benz [f] indole-4, 9-diones could be prepared by treating 2-trifluoroacetylamino-1, 4-naphthoquinone with enamines. The similar pyrrole ring formation took place by using a 2-trifluoroacetylamino-1, 4-benzoquinone to give 1H-indole-4, 7-diones. 2, 3-Disubstituted naphtho [2, 3-b] thiophene-4, 9-diones were synthesized from 2- [2- (ethoxycarbonyl) ethylthio] -1, 4-naphthoquinone and enamines. 1H-Naphtho [2, 3-c] pyran-5, 10-dione derivatives, including a natural product (pentalongin), were prepared from 2- (1-hydroxyalkyl) -1, 4-naphthoquinones and enamines (or imines). The utility of this method was demonstrated in the synthesis of pyranonaphthoquinone antibiotics, (±) -eleutherin and (±) -isoeleutherin. 1H-2-Benzopyran-5, 8-dione derivatives were similarly synthesized from 2-alkoxy-6- (1-hydroxyalkyl) -1, 4-benzoquinones. Treatment of 2-acyl-1, 4-naphthoquinones or 2-acyl-5, 6-dimethyl-1, 4-benzoquinones with enamines (or imines), followed by addition of aqueous ammonia, afforded benz [g] isoquinoline-5, 10-diones or isoquinoline-5, 8-diones, respectively.View full abstractDownload PDF (1529K) -
Tsutomu Watahiki, Takeshi Oriyama2004 Volume 62 Issue 8 Pages 821-831
Published: August 01, 2004
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSLewis acid catalyzed allylations of aldehydes with allylic metal reagents are an important carbon-carbon bond forming reaction, since they give synthetically useful homoallyl alcohols. Among various allylic metal reagents, allyltrialkylsilanes are inexpensive and non-toxic compounds compared to allylstannanes, and many allylation reactions have been developed. In recent years, the hybrid allylation reactions of aldehydes and acetals, which mean the combination of two organic reactions or modification of allylsilane, have also been investigated. These methods apply to the synthesis of various useful organic compounds by the one-step transformation and also have some outstanding green-chemical features from the point of preventing excessive consumption of resources or energy. In this article, we wish to demonstrate novel and hybrid allylation reactions of aldehydes and acetals.View full abstractDownload PDF (1598K) -
[in Japanese], [in Japanese], [in Japanese], [in Japanese]2004 Volume 62 Issue 8 Pages 832
Published: August 01, 2004
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSDownload PDF (181K) -
2004 Volume 62 Issue 8 Pages 833-838
Published: August 01, 2004
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSDownload PDF (1197K)
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