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2. Reduction of styrene compounds by hydrogen iodide.

Author

Matsumoto, Shoji, Fukaya, Yusuke, Akazome, Motohiro, and Kaiho, Tatsuo

Subjects
STYRENE, HALOGEN compounds, PROPYL group, CATALYST poisoning, IODIDES, SULFUR compounds
Abstract

Reduction of styrene compounds was achieved by the simple method of adding more than 2.5 equivalents of an aqueous HI solution in chlorobenzene under refluxing conditions for 8 h to give the product in medium to excellent yields. There was no need to add further additional reagent and catalyst. HI was a specific reagent for this reduction reaction. Increment of the amount of HI was efficient to increase the yield rather than to elongate the reaction time. This reaction could be applied to compounds bearing halogen and sulfur atoms, which would act as reductive site and poisoning of the transition-metal catalyst, respectively. The yield was decreased in the case of the compounds bearing small substituent such as propyl and butyl groups on olefin. This reaction proceeded via the iodinated intermediate followed by the reduction of C-I bond. The reduction mechanism would contain the radical cleavage of the C-I bond. [ABSTRACT FROM AUTHOR]

Published
2024
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27. Chemoselective Reduction of α,β-Unsaturated Carbonyl and Carboxylic Compounds by Hydrogen Iodide

Author

Matsumoto, Shoji, Marumoto, Hayato, Akazome, Motohiro, Otani, Yasuhiko, and Kaiho, Tatsuo

Abstract

The selective reduction of α,β-unsaturated carbonyl compounds was achieved to produce saturated carbonyl compounds with aqueous HI solution. The introduction of an aryl group at an αor βposition efficiently facilitated the reduction with good yield. The reaction was applicable to compounds bearing carboxylic acids and halogen atoms. Through the investigation of the reaction mechanism, it was found that Michael-type addition of iodide occurred to produce β-iodo compounds followed by the reduction of C-I bond via anionic and radical paths.The selective reduction of α,β-unsaturated carbonyl compounds was achieved to produce saturated carbonyl compounds with aqueous HI solution. The introduction of aryl group at αor βposition was efficient to proceed the reduction with a good yield. The reaction was able to apply the compounds bearing carboxylic acid and halogen atom.

Published
2021
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28. Disinfection of microorganisms by use of electrochemically regenerated periodate

Author

Okochi, Mina, Yokouchi, Hiroko, Yokokawa, Hiroshi, Kaiho, Tatsuo, Tae-Kyu Lim, Sakuma, Akira, Taguchi, Tomoyuki, Matsunaga, Tadashi, and Takahashi, Hiromichi

Subjects
Disinfection and disinfectants -- Research, Microorganisms -- Research, Electrochemical analysis, Biological sciences
Abstract

A new method for disinfection of microorganism by electrochemically regenerated periodate was developed. The oxidation of iodate of periodate was observed at 1.25 V versus a silver/silver chloride electrode in a cyclic voltammogram of potassium iodate and it was found that the survival rate was 0% at 1.25V.

Published
2005

29. Rapid Synthesis of D-A′-π-A Dyes through a One-Pot Three-Component Suzuki-Miyaura Coupling and an Evaluation of their Photovoltaic Properties for Use in Dye-Sensitized Solar Cells

Author

Irie, Shunsuke, primary, Fuse, Shinichiro, additional, Maitani, Masato M., additional, Wada, Yuji, additional, Ogomi, Yuhei, additional, Hayase, Shuzi, additional, Kaiho, Tatsuo, additional, Masui, Hisashi, additional, Tanaka, Hiroshi, additional, and Takahashi, Takashi, additional

Published
2016
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32. Purple fumes : the importance of iodine

Author

Küpper, Frithjof C., Feiters, Martin C., Olofsson, Berit, Kaiho, Tatsuo, Yanagida, Shozo, Zimmermann, Michael B., Carpenter, Lucy J., Luther, George W., Lu, Zunli, Jonsson, Mats, and Kloo, Lars

Subjects
Organisk kemi, Organic Chemistry
Published
2013

40. Synthesis and Evaluation of Thiophene-Based Organic Dyes Contain­ing a Rigid and Nonplanar Donor with Secondary Electron Donors for Use in Dye-Sensitized Solar Cells.

Author

Fuse, Shinichiro, Takahashi, Ryota, Maitani, Masato M., Wada, Yuji, Kaiho, Tatsuo, Tanaka, Hiroshi, and Takahashi, Takashi

Subjects
ORGANIC dyes, THIOPHENE derivatives, DYE-sensitized solar cells, ELECTRON donors, ANISOLE derivatives, ELECTROCHEMICAL analysis, SOLAR energy conversion
Abstract

We demonstrate herein the divergent synthesis of six dyes containing our originally developed rigid and nonplanar donor with three different secondary electron donors (SEDs), namely thiophene, 4-methoxybenzene, and diphenylethene. Evaluation of the photophysical properties of the synthesized dyes revealed that the introduction of the SEDs resulted in an increased absorbance in the 350-450 nm region. The influence of the SEDs on the electrochemical and photovoltaic properties depended on their structure and position of attachment. The introduction of the thiophene SED to D4π4A2, which we previously reported to be our best dye, resulted in an increased Jsc. The dye-sensitized solar cell (DSSC) prepared by using dye 2b, which contains the thiophene SED, shows a higher power conversion efficiency (PCE; η = 4.62 ± 0.02 %) and a higher incident photon-to-current conversion efficiency (IPCE) in the region 300-600 nm than D4π4A2. [ABSTRACT FROM AUTHOR]

Published
2016
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47. An Extracellular Poly(3-Hydroxybutyrate) Depolymerase from <em>Alcatigenes faecalis</em>.

Author

Tanio, Tomoharu, Fukui, Tetsuya, Shirakura, Yuri, Saito, Terumi, Tomita, Kenkichi, Kaiho, Tatsuo, and Masamune, Satoru

Subjects
POLY-beta-hydroxybutyrate, ENZYME analysis, ORGANIC compounds, COLLOIDS, GRAM-negative bacteria, POROUS materials
Abstract

A strain of Alcaligenes faecalis T1, which was isolated from activated sludge, excreted an extracellular poly(3- hydroxybutyrate) depolymerase as it grew in a medium containing poly(3-hydroxybutyrate) as the sole carbon source. The molecular weight of the enzyme, purified from the culture medium to electrophoretic homogeneity, was 48000 as determined by Sephadex G-100 filtration, and 50000 by polyacrylamide gel electrophoresis in the presence of sodium dodecylsulfate. The pH optimum for the enzyme reaction was 7.5. The purified enzyme depolymerized poly(3-hydroxybutyrate) purified from Zoogloea rwnigera I-16-M. but did not attack the bacterial native poly(3- hydroxybutyrate)-containing granules. Km values were 13.3 μg/ml (= 0.78 μM, based on an estimated average molecular weight of 17000) for poly(3-hydroxybutyrate) and 5.4mM for the trimeric ester of n(-)-3-hydroxybutyric acid. Analysis of hydrolytic products of poly(3-hydroxybutyrate), several oligomeric esters of n(-)- 3 -hydroxybutyric acid, and the methyl ester of the trimeric ester indicated that the enzyme hydrolyzed these substrates from the free hydroxyl terminus, releasing n(-)-3-hydroxybutyrate dimer units one at a time. [ABSTRACT FROM AUTHOR]

Published
1982
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