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Volume 63, Issue 4
Displaying 1-9 of 9 articles from this issue
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Akira Suzuki2005 Volume 63 Issue 4 Pages 312-324
Published: April 01, 2005
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSCarbon-carbon bond formation reactions employing organoboron compounds and organic electrophiles have been recently recognized as powerful tools for the construction of new organic compounds. Among such reactions, aromatic-aromatic (or heteroaromatic) couplings between aromatic boronic acids or esters and aromatic electrophiles providing symmetrical and unsymmetrical biaryls selectively in high yields have been used most frequently. The importance of biaryl units as components of many kinds of compounds, pharmaceuticals, herbicides, and natural products, as well as engineering materials, such as conducting polymers, molecular wires, and liquid crystals has attracted enormous interest from the chemical community. In this article such applications reported during 2001-2002 will be discussed.View full abstractDownload PDF (1564K) -
Kazunobu Toshima2005 Volume 63 Issue 4 Pages 325-338
Published: April 01, 2005
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSStudies of the interaction between the small molecules and DNA, especially the effects of the structural characteristics of the small molecules on the DNA interaction, are very important for the design of DNA targeting new drugs. In this context, the development of photochemical DNA cleaving agents, which selectively cleave DNA by irradiation with light of a specific wavelength under mild conditions and without any additives such as metals and reducing agents, is very interesting from chemical and biological standpoints and offers considerable potential in medicine especially in the post-genome era. In this article, the molecular design, chemical synthesis, DNA photocleaving property and photo-selective cytotoxicity of such novel and artificial light activatable DNA cleaving agents, which consist of DNA intercalator and carbohydrate, are describedView full abstractDownload PDF (1813K) -
Shinji Yamada2005 Volume 63 Issue 4 Pages 339-350
Published: April 01, 2005
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSThe existence of two types of intramolecular cation-π interactions between a phenyl and a pyridinium, and between a thiocarbonyl and a pyridinium in nicotinic amide derivatives have been clarified by 1H NMR and CD spectroscopies, X-ray structural analysis and calculations.
These interactions resulted in the shielding of one side of the pyridinium face by the phenyl or the thiocarbonyl group, which enables nucleophiles to attack the pyridinium ring from the opposite side. Addition of organometallic reagents and ketene silyl acetals gave 1, 4-dihydropyridines in high regio- and stereoselectivities. The stereochemistry of the chiral center of the products was opposite depending on whether the chiral auxiliary is oxazolidine or thiazolidine-2-thione.
Moreover, the DMAP derivatives bearing a thiazolidine-2-thione moiety served as asymmetric acylating catalysts. Kinetic resolution of a variety of sec-alcohols was performed in the presence of 0.5 mol% of the catalyst with the s values of 7-30.View full abstractDownload PDF (1979K) -
Ken Tanaka2005 Volume 63 Issue 4 Pages 351-358
Published: April 01, 2005
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSA novel intramolecular trans-hydroacylation of 4-alkynals leading to cyclopentenones was accomplished by using a cationic rhodium (I) complex. We also developed three types of new reactions, 1) reaction of 4-alkynals with phenol to provide cis-4-alkenoates, 2) [4 + 2] cycloaddition of 4-alkynals with alkynes to provide cyclohexenones, and 3) isomerization of 4-alkynals to 1, 3-dienals, through five-membered rhodium metallacycles generated from 4-alkynals. The asymmetric variants of this intramolecular hydroacylation reaction were successfully developed by using 3-methoxy-4-alkynals as the substrates. The present method represents an attractive new route to highly functionalized cyclopentenones and cyclobutanones.View full abstractDownload PDF (1084K) -
Kazunori Sugiyasu, Norifumi Fujita, Seiji Shinkai2005 Volume 63 Issue 4 Pages 359-369
Published: April 01, 2005
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSRecently, low molecular-weight organogel (LMOG) systems have drawn much attention not only as new functional soft-materials but also as well-defined nano-structured assemblies. In this review, molecular design and application of the second generation of LMOG are described. Firstly, stimuli-responsive organogel systems are developed. They change their molecular structure by photo- and redox-stimuli, and subsequently, their aggregation modes are controlled (sol-gel phase transition). Secondly, fluorescent organogel systems are introduced. In the organogel systems where functional dye molecules stack precisely, an unusual electron overlapping mode and an efficient energy transfer system are constructed. Thirdly, well-defined nano-structured assemblies thus designed are applied to composite materials with functional molecules, inorganic substances, and conductive polymers. By the combination of their advantages, new functional composite materials are obtained. These new findings and approaches have led us to new fields of materials chemistry and nano-chemistry.View full abstractDownload PDF (2373K) -
Nobuyuki Tamaoki2005 Volume 63 Issue 4 Pages 370-376
Published: April 01, 2005
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSThe photochromic reaction of azobenzenes has been applied to many soft materials whose functions can be controlled by the action of light. In order to accomplish a selective photochromic reaction, a new strategy utilizing a macrocyclic structure in which photochromic units are inserted into the main frame of the ring is proposed. The isomerization rate of azobenzene units from a cis form to a trans form is affected by the ring strain, the extent of which depends on the length of the spacers and the positions connecting azobenzene chromophores. This effect was applied to realize the bistability and light-intensity dependence in the photochromic systems. The concept shown here can be used for the photoresponsive molecular machines or the molecular memory.View full abstractDownload PDF (1117K) -
[in Japanese], [in Japanese], [in Japanese], [in Japanese], [in Japane ...2005 Volume 63 Issue 4 Pages 377-378
Published: April 01, 2005
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSDownload PDF (315K) -
2005 Volume 63 Issue 4 Pages 379-387
Published: April 01, 2005
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSDownload PDF (3172K) -
2005 Volume 63 Issue 4 Pages 419
Published: 2005
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSDownload PDF (318K)
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