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Volume 51, Issue 9
Displaying 1-9 of 9 articles from this issue
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Yoshio IMAI, Masaru YONEYAMA1993 Volume 51 Issue 9 Pages 794-803
Published: September 01, 1993
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSRecent studies on the synthesis of condensation polymers by using transition metal catalysts such as palladium, nickel, ruthenium, and others are reviewed from a viewpoint of new synthetic methods for condensation polymers. This article deals with the following subjects : 1) Pd-catalyzed carbon-carbon coupling polycondensation, 2) Pd- or Ni-catalyzed polycondensation via transmetallation, 3) Pd-catalyzed carbonylation polycondensation, 4) polycondensation via π-allyl Pd intermediates, 5) Ni-catalyzed aromatic homocoupling polycondensation, 6) Ru-catalyzed polycondensation, and 7) polycondensation using other transition metal catalysts.View full abstractDownload PDF (1101K) -
Yasuhiro YAMAMOTO1993 Volume 51 Issue 9 Pages 804-814
Published: September 01, 1993
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSElectrochemical preparations of the Group 10 metal isocyanide complexes containing metal-metal bonds are described. Electrochemical reductions of [MCl2(RNC)2] and [M(RNC)2(L2)]2+ (M = Pd, Pt; L2 = 2 RNC, 2 PPh3, Ph2P(CH2)nPPh2=diphos) were carried out at Pt and Hg electrodes and gave di- tri-, and high nuclear complexes, [M2Cl2 (RNC)4], [M2(RNC)4L2]2+, [M3(RNC)6L2]2+, [HgPt6(RNC)12][HgPt6(RNC)8(diphos)2], [Hg2Pt6(RNC)8(diphos)2], and [Hg2Pt6(RNC)6(diphos)3], depending on the charge consumed and reduction potential. Electrochemistry of NiX2(RNC)2 8 at a Pt electrode is quasi-reversible, but the reaction at a Hg electrode proceeded with the CE mechanism; an initial chemical reaction of 8 with a Hg electrode occurred to give [{HgNi(RNC)4X2}2], and finally the redox reaction of the Hg complex was observed. Reactions of dimeric complexes with isocyanide, ML2(M=Ni, Pt), or ML3(M=Pd) fragments were carried out and the corresponding A-frame or linear trimetallic complexes were obtained.View full abstractDownload PDF (1211K) -
Akiya OGAWA, Noboru SONODA1993 Volume 51 Issue 9 Pages 815-825
Published: September 01, 1993
Released on J-STAGE: January 28, 2010
JOURNAL FREE ACCESSNovel transition metal-catalyzed reactions of organic chalcogen compounds with acetylenes are described. In the presence of transition metal-catalysts such as Pd (PPh3)4, the addition of diaryl disulfides and diselenides to terminal acetylenes takes place stereoselectively to give high yields of (Z) -1, 2-bis (arylthio) -1-alkenes and (Z) -1, 2-bis (arylseleno) -1-alkenes, respectively. Similarly, many transition metal-complexes catalyze the addition of thiols (and selenols) to acetylenes, providing vinylic sulfides (and selenides) regioselectively. These reactions may involve vinylic metals as the intermediate. Thus, when the reaction of diaryl disulfides and diselenides with terminal acetylenes is performed under the pressure of carbon monoxide, the carbonylative addition occurs and carbon monoxide is regioselectively incorporated on the side of the terminal carbon of the acetylenes. The obtained carbonylation products, i.e., α, β-unsaturated thiolesters and selenolesters, can be reduced chemoselectively to corresponding α, β-unsaturated aldehydes by treatment with n-Bu3SnH in the presence of Pd (PPh3)4. We believe that this study will open up a new field of transition metal chemistry in combination with sulfur and selenium chemistry.View full abstractDownload PDF (1281K) -
Noboru ONO, Hisao WADA1993 Volume 51 Issue 9 Pages 826-841
Published: September 01, 1993
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSThe present paper describes a short review on the recent progress in porphyrin synthesis, where following topics of porphyrins are covered. (1) Porphyrin synthesis via biomimetic routes. (2) Synthetic methods of pyrroles for porphyrin synthesis. (3) Synthesis of unsymmetrical porphyrins with β-substituents. (4) Synthesis of meso-Tetraarylporphyrins. (5) Synthesis of 5, 15-diaryloctaalkylporphyrins. (6) Synthesis of porphyrin dimers. (7) Synthesis of dodecaarylporphyrins.View full abstractDownload PDF (1246K) -
Molecular Recognition Ability in Aqueous Solution and Bilayer MembranesJun-ichi KIKUCHI, Yukito MURAKAMI1993 Volume 51 Issue 9 Pages 842-850
Published: September 01, 1993
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSFour types of functionalized cyclophanes were prepared and their molecular recognition behavior was discussed in view of their efficiency as artificial receptors in aqueous solution and bilayer membranes. A cyclophane host bearing four L-aspartate moieties (type 1) exhibits pH-responsive molecular recognition toward various aromatic guests in aqueous media. Cage-type macrocycles, each providing a three-dimensionally extended hydrophobic cavity (type 2), are capable of incorporating guest molecules in aqueous solution through the induced-fit or the lock-and-key mechanism, depending on rigidity of their molecular frameworks. Octopus cyclophanes having eight flexible hydrocarbon branches (type 3) exercise the induced-fit binding and are superior to steroid cyclophanes bearing four rigid steroid moieties (type 4) as regards molecular recognition in aqueous media. Anionic and hydrophobic guests are effectively incorporated into the hydrophobic cavities provided by the cationic hosts of type 3 and type 4, that are embedded in bilayer membranes formed with an anionic peptide lipid; the guest-binding site being subjected to change by the structural nature of guest molecules.View full abstractDownload PDF (1174K) -
Hiroshi TSUKUBE1993 Volume 51 Issue 9 Pages 851-858
Published: September 01, 1993
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSArmed crown ethers and related armed macrocycles are presented as specific host molecules which are characterized by macrocyclic ligands and cation-ligating sidearms. Since they form dynamic and three dimensional complexes, they have potential as effective receptors, carriers, catalysts, and other functional molecular devices. This review describes new strategies for syntheses and functionalizations of armed crown ethers : (1) computer-aided molecular design of Li+ ion-specific receptors, (2) high pressure synthesis of Ag+ ion-specific carriers, (3) lipase-catalyzed optical resolution of chiral crown ethers and their application, and (4) armed crown ether-containing molecular assembly for effective Cu2+ ion separation. These clearly indicate that rational molecular design and refined synthetic method are required to develop a new, specific host molecule.View full abstractDownload PDF (1002K) -
Masako NAKAGAWA, Tomohiko KAWATE1993 Volume 51 Issue 9 Pages 859-865
Published: September 01, 1993
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSDownload PDF (991K) -
Isao SATO1993 Volume 51 Issue 9 Pages 866-867
Published: September 01, 1993
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESS -
[in Japanese], [in Japanese], [in Japanese], [in Japanese]1993 Volume 51 Issue 9 Pages 868
Published: September 01, 1993
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSDownload PDF (140K)
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