bluuebunny/crossref_metadata_2025 huggingface dataset:
Complementary Electrocyclic Reactions of o-Quinodimethanes. Highly Efficient Access to 4-Alkylideneisochroman-3-ones and 1-Carbomethoxy-3,4-dihydronaphthalenes
Authors: Shishido Kozo , Komatsu Hironori , Fukumoto Keiichiro , Kametani Tetsuji
Published: July 2006

Thermolysis of 1-alkenylbenzocyclobutenyl-1-carboxylic acid produced 4-alkylideneisochroman-3-ones in good yields via an unprecedented tandem electrocyclic-[1,5]sigmatropic process of o-quinodimethane. Alternatively, thermolysis of the corresponding methyl ester afforded the dihydronaphthalenes via E-transition state in excellent yields.
Kinetic Study on Electron Transfer Photooxygenation of Aromatic Olefins. Quenching Rates of Olefin Radical Cations by Oxygen and Superoxide Anion
Authors: Tsuchiya Masahiro , Ebbesen Thomas W , Nishimura Yoshinobu , Sakuragi Hirochika , Tokumaru Katsumi
Published: July 2006

Quenching rate constants of olefin radical cations by O2 and O2−• were measured using laser flash photolysis. The interaction of stilbene radical cations with O2−• is almost diffusion-controlled; however, the reaction of O2 with the radical cations of 1,2-diarylethylenes is more than three orders less efficient.
Hole Transfer Rates at Illuminated α-Fe2O3 Electrodes, Rate Declining in Highly Exothermic Reactions and Hole Transfer via Surface States
Authors: Itoh Kiminori , Nakajima Yasuo , Fujishima Akira
Published: July 2006

Deactivation of photogenerated holes was effectively suppressed on thin film α-Fe2O3 photoanodes with reducing agents having E0redox of ca. 0.4 V vs. NHE. This suggested that the reaction rate decreases in highly exothermic reactions and that the hole transfer takes place via surface states.
Behavior of Carbonyl Ylide Generated from 3-Chloro-3-(p-nitrophenyl)diazirine and Acetone. 1,3-Dipolar Cycloaddition to Benzaldehyde and Epoxide Formation
Authors: Ibata Toshikazu , Toyoda Jiro , Liu Michael T H
Published: July 2006

A carbonyl ylide generated from 3-chloro-3-(p-nitrophenyl)diazirine and acetone either 1,3-dipolar cycloadds to benzaldehydes to afford 2,2-dimethyl-4-aryl-5-(p-nitrophenyl)-dioxole or intramolecularly cyclizes to give 2-chloro-2-methyl-3-(p-nitrophenyl)-3-propanone and 2-methyl-3-(p-nitrophenyl)-1-propene-3-one as final products.
Stereoselective Preparation of β-C-Glycosides from 2-Deoxyribose Utilizing Neighboring Participation by 3-O-Methylsulfinylethyl Group
Authors: Narasaka Koichi , Ichikawa Yuh-ichiro , Kubota Hideki
Published: July 2006

Acid catalyzed reaction of 2-deoxy-3-O-methylsulfinylethyl-ribofuranosyl acetate with silyl enol ethers proceeded stereoselectively, resulting in the predominant formation of the corresponding β-C-glycosides.
Preparation and Crystal Structure of Binuclear Manganese(II) Complex Exhibiting Multiline ESR Signal
Authors: Nishida Yuzo
Published: July 2006

Binuclear manganese(II) complex with 2-[bis(2-pyridylmethyl)aminomethyl]-4-nitrophenol, which exhibits a multiline ESR signal, was prepared, and its crystal structure was determined by X-ray diffraction method.
A Practical Synthesis of Several Polyhydroxylated Chiral Building Blocks
Authors: Kusakabe Masato , Kato Hiroshi , Sato Fumie
Published: July 2006

A practical method for the synthesis of several useful polyhydroxylated chiral building blocks has been developed. The key reaction is the kinetic resolution of (E)-1-trimethylsilyl-4-alkoxy-1-buten-3-ol or (E)-1-trimethylsilyl-5-alkoxy-1-penten-3-ol using the Sharpless asymmetric epoxidation reaction.
Competitive Photochemical Reactions of Azidomanganese(III) Tetraphenylporphyrin in 2-Methyltetrahydrofuran
Authors: Imamura Taira , Yamamoto Yuichi , Suzuki Toru , Fujimoto Masatoshi
Published: July 2006

The photoirradiation of MnIII(tpp)N3 (tpp = meso-tetraphenylporphinato) in the fluid solutions of 2-methyltetrahydrofuran at temperatures of 0 to −70 °C causes competitive reactions between the oxidation of the central manganese of the complex to yield MnV(tpp)N and the reduction to MnII(tpp). The reduction and the oxidation proceed advantageously at 25 °C and at −80 °C respectively.
Temperature Dependence of Elastic Properties of YBa2Cu3O7−x, Superconductor
Authors: Yoshimoto Mamoru , Tanabe Setsuhisa , Soga Naohiro
Published: July 2006

The elastic properties were investigated for the high Tc superconductor YBa2Cu3O7−x from the liquid-nitrogen temperature to room temperature. Sound velocities and elastic moduli increased with decreasing temperature down to about Tonset (95 K), below which they decreased with decreasing temperature. The Debye temperature was also calculated to be 350 K.
Selective Acceleration Effects of K-Addition in Hydrogenolysis of Cyclohexane over Ruthenium Supported on Silica
Authors: Lin Zheng-zhong , Okuhara Toshio , Misono Makoto
Published: July 2006

By addition of K to Ru/SiO2 catalyst (K/(K+Ru)=0.2), catalytic activity for hydrogenolysis of cyclohexane was enhanced, whereas those for dehydrogenation of cyclohexane and hydrogenation of CO were markedly suppressed.
Magnetic Field Effect as a Probe for Radical Pair Intermediates in the Photoreactions of Nitroaromatic Ethers
Authors: Mutai Kiyoshi , Nakagaki Ryoichi , Tukada Hideyuki
Published: July 2006

Intermediacy of a radical ion pair in the photo-Smiles rearrangement of N-[2-(4-nitro-1-naphthoxy)ethyl]aniline in CH3CN was suggested on the basis of magnetic field effects on the photoreaction of its higher homolog.
Synthesis and Properties of Tetrakis(alkylseleno)tetrathiafulvalene
Authors: Yamochi Hideki , Iwasawa Naoko , Urayama Hatsumi , Saito Gunzi
Published: July 2006

A series of tetrakis(alkylseleno)tetrathiafulvalene (TSeCn-TTF; n = 1–18) has been synthesized. The melting points of this series showed the same dependency on the length of alkyl chains as the sulfur and the tellurium analogues. The g-values of the TYC1-TTF cation radicals (Y = sulfur, selenium, and tellurium) are compared.
Total Synthesis of Dictymal, a B-seco-Dictymenoid Aldehyde from an Alga, Diatyota diohotoma
Authors: Kato Nobuo , Tanaka Shinya , Kataoka Hideo , Takeshita Hitoshi
Published: July 2006

A B-seco-dictymenoid aldehyde, dictymal, was synthesized from two optically active iridoid synthons; the required ring system was constructed by lactol-regulated Cope rearrangement and stereoselective Li-tert-BuOH-in-HMPA reduction of the tetrasubstituted C=C.
One Evidence Supporting that Thymidylate Synthetase and Thymidine Kinase Are the Rate-determining Enzymes of DNA Synthesis in Regenerating Rat Liver
Authors: Tsukamoto Ikuyo , Kojo Shosuke
Published: July 2006

The integration of the activities of thymidylate synthetase and thymidine kinase is shown to correlate closely with the amount of DNA synthesis. Based on the result, these enzymes are suggested to be the rate-determining enzymes of DNA synthesis in regenerating rat liver.
Preparation of Tetrahydrofurfuryl Alcohol Derivatives with Electron-Withdrawing Substituents from 4-Acetoxy-1,5-dibromopentane Derivatives by Treatment with Silver Nitrate
Authors: Mitani Michiharu , Takeuchi Hiroshi , Koyama Kikuhiko
Published: July 2006

When 4-acetoxy-1,5-dibromopentane derivatives having the electron-withdrawing groups at the 1-position, which were obtained by Cu(I)-catalyzed photochemical addition of 2-acetoxy-1,3-dibromopropane to electron-deficient olefins, were subjected to treatment with silver nitrate, tetrahydrofurfuryl alcohol derivatives with the electron-withdrawing groups at the 5-position were obtained.
Preparation of an Open-Chain Polyimide
Authors: Kurita Keisuke , Yamakawa Masahiro , Koyama Yoshiyuki
Published: July 2006

A high molecular weight open-chain polyimide was prepared for the first time from benzyloxyamine and terephthaloyl chloride. It showed high solubility in contrast to the conventional polyimides.
Gas Phase Negative Ion Chemistry of 6-Oxa-3-sila- and Germabicyclo[3.1.0]hexanes
Authors: Damrauer Robert , Weber William P , Manuel Georges
Published: July 2006

Ion-molecule reactions between fluoride and 1,3,3-trimethyl-6-oxa-3-silabicyclo[3.1.0]hexane, 2,7-dimethyl-2,3:7,8-diepoxy-5-spiro[4.4]nonane, and 3,3-dimethyl-6-oxa-3-germabicyclo[3.1.0]-hexane are reported. Attack by fluoride at either silicon or germanium results in loss of either isoprene or butadiene, respectively. An analogous reaction with amide ion is reported.
A Novel Functionalized Polysulfides. Preparation of Polysulfides Containing Spiroorthocarbonate Moiety in the Main Chain
Authors: Tagoshi Hirotaka , Endo Takeshi
Published: July 2006

Preparation of polysulfides containing spiroorthocarbonate structure in the main chain by the radical polyaddition of unsaturated spiroorthocarbonate, 2,7-dimethylene-1,4,6,9-tetra-oxaspiro[4.4]nonane, with dithiols is described.
Kinetics of Pyridine Derivatives as Accelerators for the Incorporation Reaction of Cadmium(II) into Porphyrin and Association Behavior of the Accelerators with Porphyrin
Authors: Kawamura Kunio , Kasahara Hiroshi , Igarashi Shukuro , Yotsuyanagi Takao
Published: July 2006

Incorporation reaction rate constants of cadmium(II) ion into 5,10,15,20-tetrakis(4-sulphonatophenyl)porphine (H2tpps) in the presence of 8 kinds of pyridine derivatives as accelerators were determined. And association constants for 5 kinds of the accelerators with H2tpps were also determined; the logarithmic values of which were proportional to the number of pyridine rings. The association constant is found to be one of the most important factors for controlling the acceleration effect.
Photoassisted C–H Bond Activation with RhCl(CO)(PR3)2 in the Presence of Isocyanides Leading to Catalytic Formation of Aldimines
Authors: Tanaka Masato , Sakakura Toshiyasu , Tokunaga Yuko , Sodeyama Touru
Published: July 2006

C–H bond activation of benzene and pentane in the presence of isocyanides was promoted by RhCl(CO) (PR3)2 to result in the isocyanides insertion into C–H bonds.
Catalytic C–H Activation. Silylation of Arenes with Hydrosilane or Disilane by RhCl(CO)(PMe3)2 under Irradiation
Authors: Sakakura Toshiyasu , Tokunaga Yuko , Sodeyama Touru , Tanaka Masato
Published: July 2006

Direct silylation of arenes with triethylsilane or hexamethyldisilane were catalyzed by RhCl(CO)(PMe3)2 under irradiation.
Asymmetric Diels–Alder Reaction by the Use of a Chiral Titanium Catalyst with Molecular Sieves 4A. Remarkable Solvent Effect on the Enantioselectivity
Authors: Narasaka Koichi , Inoue Masayuki , Yamada Tohru , Sugimori Jun , Iwasawa Nobuharu
Published: July 2006

A remarkable effect of solvent on the enantioselectivity was observed in the asymmetric Diels–Alder reaction of 3-(2-alkenoyl)-1,3-oxazolidin-2-ones and dienes catalyzed by a chiral titanium reagent, and the Diels–Alder adducts were obtained in high enantioselectivity when alkyl-substituted benzenes were employed as the solvent.
Unusual Effect of Methylation of a Benzene Ring on the Strength of Phenyl–Phenyl Interaction
Authors: Ito Masato M , Kato Jun-ichi , Takamura Ichiro , Wakatsuki Kyoko , Endo Tadashi
Published: July 2006

Gas-chromatographic studies have shown that the strength of the weak interaction between a phenyl group in a stationary liquid and a benzene molecule in a sample alters most greatly when, among various substituents examined (e.g., Me, Et, Cl, and OMe), a methyl group—a “simple” nonpolar group—is introduced into a benzene ring in the sample.
Estimation of α-Helix Content in Keratin Fibers by Differential Scanning Calorimetry
Authors: Koga Joichi , Shibano Michihiro , Nishio Etsuo
Published: July 2006

In the DSC curves of α-keratin (intact wool keratin) an endothermic peak was observed at the temperature around 232 °C which had been interpreted in terms of helix melting point. When wool fiber was stretched the native α-keratin transformed to stretched β-keratin and the meantime, the endothermic peak decreased with stretching and finally disappeared. This DSC measurement was thought to be great advantage to confirm the existence of α-form in keratin fibers.
Crystal and Electronic Structures of (BEDSe-TSeF)AuBr2
Authors: Kato Reizo , Kobayashi Hayao , Kobayashi Akiko , Mori Takehiko , Inokuchi Hiroo
Published: July 2006

The crystal of the semiconducting 1:1 compound of BEDSe-TSeF, (BEDSe-TSeF)AuBr2 (ρR.T.=7 Ω cm, Ea=0.13 eV) contains a two-dimensional array of closely spaced donor molecules. Half the AuBr2 anions are distributed into this cation sheet, and electrostatically stabilize the sheet structure, indicating a new way to obtain stable multi-dimensional crystal structure.
An Enantioselective Synthesis of (−)-Fortamine1)
Authors: Kamiyama Keiji , Kobayashi Susumu , Ohno Masaji
Published: July 2006

The aminocyclitol moiety of fortimicin A, (−)-fortamine, was synthesized in an enantioselective manner starting from the chiral half ester, easily available by the enantioselective hydrolysis of a symmetrical diester with pig liver esterase. The present approach provides a general and efficient route to variously substituted 1,4-diaminocyclitol-derivatives.
Z-1,2-Bis(t-butyldimethylsilyl)-1,2-bis(trimethylsilyl)ethylene. The Most Crowded Known cis-Olefin
Authors: Sakurai Hideki , Ebata Keisuke , Kabuto Chizuko , Nakadaira Yasuhiro
Published: July 2006

Z-1,2-Bis(t-butyldimethylsilyl)-1,2-bis(trimethylsilyl)ethylene was prepared, the structure being determined by X-ray crystallography. Remarkably, the compound is fixed to cis configuration and a considerable pyramidarization occurs at olefinic carbons with large twisting of the double bond.
Matrix Isolation and Ultraviolet Spectra of Germylenes
Authors: Ando Wataru , Tsumuraya Takeshi , Sekiguchi Akira
Published: July 2006

Some organogermylenes were isolated in a hydrocarbon matrix at low temperature by the photolysis of 7-germanorbornadienes or bis(trimethylsilyl)germanes. The germylenes show electronic absorption bands at 420–560 nm.
Studies on the Stereochemistry in the Alkylation of Enolate Ion of Cyclic β-Keto Ester with Sulfonium Salts Containing Optically Active Alkyl Groups
Authors: Kobayashi Michio , Umemura Kazuyuki , Matsuyama Haruo
Published: July 2006

Alkylation of cyclic β-keto ester with racemic sulfonium salts containing optically active alkyl groups such as (S)-2-octyl and (S)-2-butyl was found to afford C-alkylated products with inversion of configuration at asymmetric alkyl carbon atom. Stereochemical reaction course via formation of S–O sulfurane intermediate and successive stereoselective intramolecular alkyl migration to enolate is described.
The Chemistry of Isopyrene (Azuleno[2,1,8-ija]azulene). Oxidations
Authors: Vogel Emanuel , Schmalstieg Lutz , Weyer Hans-Jürgen , Gleiter Rolf
Published: July 2006

The nonbenzenoid aromatic hydrocarbon isopyrene undergoes some exceptional—synthetically useful—oxidative transformations, in accord with theoretical arguments, it reacts with bidentate oxidants preferentially at the “central C=C bond” to give bridged [H]annulenes with an anthracene perimeter.
Preparation of Tetrahydropyran Derivatives with α-Electron-Withdrawing Substituents from 1,5-Dibromopentane Derivatives by Treatment with Silver Nitrate
Authors: Mitani Michiharu , Takeuchi Hiroshi , Koyama Kikuhiko
Published: July 2006

When 1,5-dibromopentane derivatives having the electron-withdrawing groups at one terminus, which were obtained by Cu(I)-catalyzed photochemical addition of 1,3-dibromopropanes to electron-deficient olefins, were subjected to treatment with silver nitrate, tetrahydropyran derivatives with the electron-withdrawing groups at the α-position to the oxygen atom were obtained.
Stereochemical Investigation of Photoepoxidation of Dioxetane-forming Olefins in the Presence of Sulfur Dioxide
Authors: Ando Wataru , Sonobe Hideki , Akasaka Takeshi
Published: July 2006

Photosensitized oxygenation of two stereoisomeric di-t-butyl-bis(bicyclo- [3.3.1] non-9-y1idenes) in the presence of sulfur dioxide afforded the corresponding epoxide stereospecifically.
One Step Vinylic Chlorination with Benzeneseleninyl Chloride
Authors: Kamigata Nobumasa , Satoh Takeshi , Yoshida Masato , Kobayashi Michio
Published: July 2006

The reaction of benzeneseleninyl chloride with olefins in the presence of aluminum chloride or ruthenium(II) phosphine complex under mild conditions was found to give α-chloro-olefins in one step.
Reaction of Arylazo Aryl Sulfone with Olefins in the Presence of Tetrakis(triphenylphosphine)palladium(0)
Authors: Kamigata Nobumasa , Kondoh Tetsuya , Kameyama Masayuki , Satoh Takeshi , Kobayashi Michio
Published: July 2006

Catalytic reaction of arylazo aryl sulfone with olefins in the presence of tetrakis(triphenylphosphine)palladium(0) was investigated. Arylation of olefins was the major product, and 1:1 adduct of arylazo and arenesulfonyl group to olefins was obtained as minor product. Diarylpalladium(II) species was proposed as an intermediate in this reaction.
Ester Enolate Claisen Rearrangement via Boat-Like Transition State
Authors: Uchiyama Harumi , Kawano Mika , Katsuki Tsutomu , Yamaguchi Masaru
Published: July 2006

The Claisen rearrangement of ester enolates with appropriate metal ions bearing bulky cyclopentadienyl ligands was found to proceed through a boat-like transition state leading to the products with the different configuration from that expected from a chair-like transition state.
A Convenient Preparation of Optically Active 1,1′-Binaphthyl-2,2′-diol via Enzymatic Hydrolysis of the Racemic Diester
Authors: Miyano Sotaro , Kawahara Kan , Inoue Yoshio , Hashimoto Harukichi
Published: July 2006

Commercially available porcine pancreatic lipase can conveniently be utilized for a highly enantioselective hydrolysis of valeric acid diester of racemic 1,1′-binaphthyl-2,2′-diol to give the (S)-diol (95% ee at 46% conversion).
Cytotoxic Squalene-Derived Polyethers from the Marine Red Alga Laurencia obtusa (Hudson) Lamouroux
Authors: Suzuki Teruaki , Takeda Satoshi , Suzuki Minoru , Kurosawa Etsuro , Kato Arata , Imanaka Yoshihiko
Published: July 2006

Five new cytotoxic triterpenoids with squalene carbon skeleton have been isolated from the title alga. The structures of 15(28)-anhydrothyrsiferyl diacetate, 15-anhydrothyrsiferyl diacetate, and magireol-A were confirmed by the spectral and chemical methods. The structures of magireol-B and -C were deduced from the spectral data.
Photolyses of 2-(Alkylthio)carbonyl-2-(arylethyl)propyl Cobaloxime
Authors: Tada Masaru , Nakamura Tatsuya , Matsumoto Mitsuhiro
Published: July 2006

2-(Alkylthio)carbonyl-2-(arylethyl)propyl cobaloximes were photolyzed. When an aryl group is phenyl, a major process is a radical cyclization to give 2-(alkylthio)carbonyl-2-methyltetralin. On the other hand, β-thiolactone is a major product when an aryl group is mesityl and an alkyl group is t-butyl.
Enantioselective Syntheses of (+)- and (−)-Frontalin
Authors: Ohwa Masaki , Eliel Ernest L
Published: July 2006

(+)- and (−)-Frontalin have been obtained from a chiral 1,3-oxathiane precursor in a short (3-step) synthesis in moderate (70%) enantiomeric excess (e.e.). A longer (6-step) modification gives the two enantiomers in 96% e.e. Overall yields range from 28 to 43%.
Decomposition of Methanol to Syngas over AlPO4-Supported Nickel Catalyst
Authors: Tada Akio , Yoshino Takumi , Itoh Hidenobu
Published: July 2006

An AlPO4-supported nickel catalyst exhibited significantly higher activity and selectivity for the title reaction than such conventional catalysts as Ni/Al2O3, Ni/SiO2, Ni/TiO2, and CuO–ZnO–Cr2O3. The effects Of Ni loading and temperatures of reduction and reaction on its catalytic property were also investigated.
Oxidoreduction between Cycloalkanols and Cycloalkanones in the Cultured Cells of Nicotiana tabacum. Simulation of the Time-courses in the Oxidation of (+)-Borneol and the Reduction of (−)-Carvomenthone
Authors: Suga Takayuki , Izumi Shunsuke , Hirata Toshifumi , Hamada Hiroki
Published: July 2006

The time-courses in the oxidation of (+)-borneol and the reduction of (−)-carvomenthone in the cultured cells of Nicotiana tabacum were simulated on the basis of the permeability of 5- to 7-membered cycloalkanols and their corresponding cycloalkanones into the cultured cells and the 13C NMR chemical shift of the carbonyl carbon of (+)-camphor which is the oxidation product of (+)-borneol and (−)-carvomenthone which is a substrate for the reduction, respectively.
Reaction of Bis(heptafluorobutyryl) Peroxide with Carbanions and a Thiolate Anion
Authors: Yoshida Masato , Shimokoshi Kazuaki , Kobayashi Michio
Published: July 2006

In the reaction of bis(heptafluorobutyryl) peroxide with carbanions and a thiolate anion, two types of reactions were observed; one is an electron transfer reaction to give perfluoropropylated compounds and the other is a nucleophilic substitution.
Crystal and Electronic Structures of a New Molecular Superconductor, κ-(BEDT-TTF)2I3
Authors: Kobayashi Akiko , Kato Reizo , Kobayashi Hayao , Moriyama Shinji , Nishio Yutaka , Kajita Koji , Sasaki Wataru
Published: July 2006

The crystal of a new ambient-pressure superconductor, κ-(BEDT-TTF)2I3 belongs to the monoclinic system with space group P21/c and a=16.387, b=8.466, c=12.832 Å and β=108.56°. The 2-dimensional(2D) metal sheets composed of paired BEDT-TTF molecules and the I3 anion sheets are arranged alternately along the a. direction. The orientation of the neighbouring paired molecules is almost perpendicular to each other.
1H-Nuclear Magnetic Resonance Studies on Cobalt(II) Complexes of N-Alkyl-octaethylporphyrins
Authors: Aoyagi Katsuhiro , Toi Hiroo , Aoyama Yasuhiro , Ogoshi Hisanobu
Published: July 2006

High-spin cobalt(II) complexes of N-alkyl-octaethylporphyrin have been characterized by 1H-NMR measurements. Proton signals of N-alkyl groups and aromatic meso-protons were assigned by deuteration method. Axially coordinated imidazole resonance appeared at very low magnetic field.
A Convenient Preparation of α-(p-Hydroxy- or p-Aminophenyl) Carbonyl Compounds. Addition–Reduction Reaction of Tin(II) Enolate with p-Benzoquinone and Its Mono-N-tosylimino Derivative
Authors: Mukaiyama Teruaki , Clark Richard S J , Iwasawa Nobuharu
Published: July 2006

Tin(II) enolates react with p-benzoquinone and its mono-N-tosylimino derivative to give 1,2-adducts in good yield. These can be reduced in situ to α-(p-hydroxy- or p-aminophenyl) carbonyl derivatives by addition of dichloromethylsilane and dimethylaminopyridine.
High Catalytic Activity of Sm2O3 for Oxidative Coupling of Methane into Ethane and Ethylene
Authors: Otsuka Kiyoshi , Komatsu Takayuki
Published: July 2006

The catalytic activity of Sm2O3 for oxidative coupling of CH4 was measured at the conditions: P(CH4)/P(O2)=6, P(O2)=14.5 kPa, W/F=0.000223–0.0891 g·h·l−1 , and T=750 °C. STY of C2-compounds reached to 2.98 mol·g−1·h−1 at W/F of 0.000223 g·h·l−1. The catalytic activity of Sm2O3 was one to three orders of magnitude greater than those reported for other metal oxides.
An Efficient and Extremely Mild Catalyst System, Combined Use of Trityl Chloride and Tin(II) Chloride, in the Aldol and Michael Reactions
Authors: Mukaiyama Teruaki , Kobayashi Shu , Tamura Masanori , Sagawa Yukihiro
Published: July 2006

The aldol reaction of silyl enol ethers with acetals or aldehydes, and the Michael reaction of silyl enol ethers with α,β-unsaturated ketones are efficiently catalyzed by the combined use of trityl chloride and tin(II) chloride under extremely mild conditions.
Syntheses of 1,3- and 1,4-Dienes by the Oxidative Coupling of 1-Alkenylstannanes and 2-Alkenylstannanes in the Presence of Palladium Catalyst
Authors: Kanemoto Shigekazu , Matsubara Seijiro , Oshima Koichiro , Utimoto Kiitiro , Nozaki Hitosi
Published: July 2006

Treatment of 1-alkenylstannanes with tBuOOH in the presence of palladium catalyst gives 1,3-dienes. Cross coupling reaction between 1-alkenylstannanes and 2-alkenylstannanes provides 1,4-dienes selectively in good yields.
The Reaction of Samarium(III) Iodide with Samarium Metal in Tetrahydrofuran, A New Method for the Preparation of Samarium(II) Iodide
Authors: Imamoto Tsuneo , Ono Mitsumasa
Published: July 2006

Samarium(III) iodide reacts with samarium metal in tetrahydrofuran under mild conditions to afford samarium(II) iodide in almost quantitative yield. A solution of samarium(II) iodide in tetrahydrofuran is prepared from samarium metal and iodine.
Crystal Structure of Cholesteryl Perfluoropropionate at 173 K
Authors: Tamura Hatsue , Sato Tomohiro , Ogawa Kazuhide , Yano Shinichi , Sakaguchi Kenichi , Matsuura Yoshiki
Published: July 2006

The molecular structure of cholesteryl perfluoropropionate(CPFP) was determined by X-ray analysis. The side chain at C(17) has an extended conformation, while the perfluoropropionate chain at C(3) is disordered in a bent conformation. The molecules, the best planes through the tetracyclic ring-system of which are nearly parallel to the ac plane, form a layered structure.
Isolation, Structural Elucidation, and Total Synthesis of Epiisocitreoviridinol
Authors: Nishiyama Shigeru , Shizuri Yoshikazu , Toshima Hiroaki , Ozaki Masami , Yamamura Shosuke , Kawai Kazuaki , Kawai Noriaki , Furukawa Hideyuki
Published: July 2006

Epiisocitreoviridinol, biogenetically relevant to citreoviridinol, has been isolated as a new metabolite of Penicillium citreo-viride B. (IFO 6049). Its stereostructure including the absolute configuration has been determined unambiguously by its total synthesis in optically active form.
A New Synthesis of Optically Active trans β-Amino Alcohols by Asymmetric Ring-opening of Symmetrical Oxiranes
Authors: Yamashita Hiroyuki
Published: July 2006

The asymmetric ring-opening of symmetrical oxiranes with aniline or trimethylsilyl azide is effectively catalyzed by zinc (2R,3R)-tartrate or cupric (2R,3R)-tartrate to give trans  N-phenyl (β-amino alcohol or trans  O-trimethylsilyl 2-azido alcohols in 17–52% ee. The latter azido products can be easily converted into optically active trans β-amino alcohols by two-step procedure.
Molecular Structure of a New Multi-Sulfur π-Donor Molecule, Bis(vinylenedithio)tetrathiafulvalene, VT and Crystal and Electronic Structures of VT2PF6
Authors: Kobayashi Hayao , Kobayashi Akiko , Nakamura Tadashi , Nogami Takashi , Shirota Yasuhiko
Published: July 2006

Multi-sulfur π-donor molecule, bis(vinylenedithio)tetrathiafulvalene, VT, is non-planar. Examination of crystal and electronic band structures revealed the one-dimensional nature of VT2PF6.
Condensation of 1-Fluorofuranoses and Silylated Nucleobases Catalyzed by Tetrafluorosilane
Authors: Noyori Ryoji , Hayashi Masahiko
Published: July 2006

The title reaction provides a generally useful tool for nucleoside synthesis. The stereoselectivities are highly influenced by the fluoride substrates, and steric course of the reaction of O-benzylated ribofuranosyl fluoride is solvent dependent.
Effect of H2S on Hydrogenation Activity of Sulfided Co/Mo/Al2O3
Authors: Yamada Muneyoshi , Saito Atsushi , Wakatsuki Toshitaka , Obara Toshiyuki
Published: July 2006

Effect of gas-phase H2S on the reactions of aromatic hydrocarbons over sulfided Co/Mo/Al2O3 was studied at 400 °C. The added H2S inhibited hydrogenation of benzene but accelerated hydrogenation of o-xylene. No effect was exerted upon hydrogenation of toluene. At all instances, the added H2S accelerated skeletal isomerization.
Carbon Monoxide Hydrogenation on SiO2−, Al2O3−, or TiO2-Attached Nb-Monomer Catalysts
Authors: Nishimura Madoka , Asakura Kiyotaka , Iwasawa Yasuhiro
Published: July 2006

The new low-valent Nb monomer catalysts which were prepared by taking advantage of the reaction between Nb(η3-C3H5)4 and surface OH groups on SiO2, Al2O3, or TiO2, followed by the treatments with H2, were found to be active for the hydrogenation of carbon monoxide in which C2–C4 hydrocarbons were mainly produced in the temperature range 423–598 K. In contrast, only the disproportionation reaction of CO to form CO2 proceeded on usual impregnation Nb catalysts and Nb2O5.
Strong Binding Ability of Lipophilic Cyclodextrins for Alkali Metal and Alkaline Earth Metal Ions
Authors: Ueno Akihiko , Sasaki Hiroshi , Fukushima Mitsuru , Minato Shingo , Osa Tetsuo
Published: July 2006

Lipophilic cyclodextrins bearing seven 2-naphthalenesulfonyl moieties at primary (C6) side of β-cyclodextrin exhibited marked binding ability for alkali metal and alkaline earth metal ions in dichloromethane.
Chemical Reactions in the Medium Density Fluid. Anomaly in the Volume Profile of the Dimerization Reaction of 2-Methyl-2-nitrosopropane in Carbon Dioxide
Authors: Kimura Yoshifumi , Yoshimura Yosuke , Nakahara Masaru
Published: July 2006

Pressure effects on the dimerization-dissociation reaction of 2-methyl-2-nitrosopropane in carbon dioxide were studied in the wide range of density. The volume profile of the reaction exhibited a remarkable difference between in the high and the medium density regions.
Bromination of Phenols by Use of Benzyltrimethylammonium Tribromide
Authors: Kajigaeshi Shoji , Kakinami Takaaki , Tokiyama Hajime , Hirakawa Takahiro , Okamoto Tsuyoshi
Published: July 2006

The reaction of phenols with benzyltrimethylammonium tribromide in dichloromethane-methanol for 1 h at room temperature gave polybromophenols in good yields.
Carbon-14 Kinetic Isotope Effect in Reduction of Benzophenone with Lithium Isopropoxide
Authors: Yamataka Hiroshi , Hanafusa Terukiyo
Published: July 2006

The carbon-14 kinetic isotope effect (KIE) was determined for the reduction of benzophenone-carbonyl-14C with lithium isopropoxide in THF at 25 °C. The observed KIE (12k⁄14k=1.045) suggested that there is considerable bonding change at the carbonyl carbon in the transition state. This is the first example of carbon KIE in a reaction which proceeds via initial electron transfer followed by a slow radical process.
Charge Transfer Interaction in Homomolecular Crystals of Azacycl[3.3.3]azine Derivatives
Authors: Akhtar Shamim , Tanaka Jiro , Ashwell Geoffrey J , Shaw John T
Published: July 2006

The electronic spectra and structure of the single crystals of azacycl[3.3.3]azine derivatives have been investigated by the reflection and absorption measurements. In addition to the π-π* transitions of in-plane polarization, the out of plane polarized transition have been found which are due to the intermolecular charge transfer transition between the stacked molecules of the same species.
New Kinetic Evidence for Inversional Mechanism in Thermal Geometrical Isomerization about Carbon–Nitrogen Double Bond
Authors: Asano Tsutomu , Okada Toshio
Published: July 2006

Kinetic pressure and solvent effects were studied for geometrical isomerization about carbon-nitrogen double bond in N,N-dimethyl-N′-[(4-nitrophenyl)methylene]-1,4-benzenediamine and 4-[[4-(dimethylamino)phenyl]imino]-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one. In both of the compounds, the effects clearly demonstrate that the polarity of the reactant decreases slightly during activation, and the results can hardly be reconciled with the previously proposed rotational mechanism.
Halogenolysis of Benzylcobaloximes
Authors: Gupta B D , Kumar Manoj
Published: July 2006

The reaction of substituted benzylcobaloximes p-RC6H4CH2Co(dmgH)2Py (R = OMe, NHCOCH3 and NMe2) and m-RC6H4CH2Co(dmgH)2Py (R = Me, OMe) with halogens (Cl2 and Br2) in chloroform under nitrogen forms ring substituted organic and organometallic products.
Organoborane-Catalyzed anti-Markownikoff Hydration of Olefins
Authors: Maruoka Keiji , Sano Hiromi , Shinoda Kiyotaka , Yamamoto Hisashi
Published: July 2006

A new, catalytic procedure for the anti-Markownikoff hydration of olefins in the presence of organoborane catalyst and dichloroaluminum hydride under dry air has been described.
A Significant Substituent Effect on the Stereochemistry of the Trityl Salt-Catalyzed Michael Reaction
Authors: Mukaiyama Teruaki , Tamura Masanori , Kobayashi Shu
Published: July 2006

In the presence of a catalytic amount of trityl salts, silyl enol ethers of thioesters react with α-substituted α,β-unsaturated cyclic ketones to afford the corresponding Michael adducts in good yields with excellent lk diastereoselectivities.
Efficient Solar to Chemical Conversion with an n-Type Amorphous Silicon/p-Type Crystalline Silicon Heterojunction Electrode
Authors: Ueda Keiichi , Nakato Yoshihiro , Sakamoto Hiromi , Sakai Yuichi , Matsumura Michio , Tsubomura Hiroshi
Published: July 2006

An n-p heterojunction silicon (Si) electrode was prepared by depositing an n-type amorphous Si layer on a p-type crystalline Si wafer by the plasma CVD method. It worked as an efficient hydrogen evolving photocathode when coated with a thin platinum layer as a catalyst. A photoelectrochemical cell was constructed with an electrode of this type and a platinum counter electrode separated by a cation exchange membrane. It decomposed hydrogen iodide into hydrogen and iodine with the conversion efficiency of 10.8% (AM1, 100 mW/cm2), the highest of the efficiencies so far reported for the solar-to-chemical conversion without an external bias.
Synthesis of N,N′-Disalicylidene-ethylenediamine(Salen)-Porphyrin Combined System with Constrained Conformations
Authors: Maruyama Kazuhiro , Kobayashi Fumikazu , Osuka Atsuhiro
Published: July 2006

Salen-capped porphyrin and salen-bridged porphyrin dimer as well as their zinc and nickel complexes were synthesized. In the capped complex, the nickel-salen moiety was rigidly held over the porphyrin ring, while preferred conformations of salen-bridged porphyrin dimers were controlled by the metal complexation.
Asymmetric Epoxidation of Homoallylic Alcohols Using Zirconium Tetrapropoxide, Dicyclohexyltartramide, and t-Butyl Hydroperoxide System
Authors: Ikegami Satoru , Katsuki Tsutomu , Yamaguchi Masaru
Published: July 2006

In the asymmetric epoxidation of homoallylic alcohols, a combination of zirconium tetrapropoxide, dicyclohexyltartramide, and t-butyl hydroperoxide was found to give good enantiomeric selectivities (up to 77% ee) especially for (Z)-homoallylic substrates.
Palladium(0)-catalyzed Synthesis of 2-Alkylbenzothiazoles by a Novel Thiation of 1-Amino-2-iodoarenes with Thioamides
Authors: Takagi Kentaro , Iwachido Tadashi , Hayama Naomi
Published: July 2006

Pd(0) catalyzed the reaction of 1-amino-2-iodoarenes with thioamides giving rise to 2-XCH2-substituted benzothiazoles (X=H, CH3, OCH3, and CN) directly.
Highly Effective Catalytic Asymmetric Hydrogenations of α-Keto Esters and an α-Keto Acetal with New Neutral Chiral Pyrrolidinebisphosphine-Rhodium Complexes
Authors: Takahashi Hisashi , Morimoto Toshiaki , Achiwa Kazuo
Published: July 2006

Synthesis of new chiral pyrrolidinebisphosphine–rhodium complexes and their application to the asymmetric hydrogenations of α-keto esters and an α-keto acetal are described. Among them, MCCPM-Rh gave the highest optical yield (87%) of the α-hydroxy ester and MCPM-Rh gave the 75% optical yield of the α-hydroxy acetal at the substrate to catalyst ratio (1000:1).
Variable Pressure and Temperature Nuclear Magnetic Resonance Study of Solvent Exchange on Manganese(II) Ion in N,N-Dimethylformamide. Influence of Solvent Molecular Size on Solvent Exchange Mechanism
Authors: Ishii Masao , Funahashi Shigenobu , Tanaka Motoharu
Published: July 2006

The solvent exchange rates for manganese(II) ion in DMF have been measured at various pressures up to 300 MPa by the high-pressure oxygen-17 NMR line-broadening method. The activation volume of 1.6±0.5 cm3 mol−1 points to an interchange mechanism operative in the exchange process. This is discussed in terms of the bulkiness of DMF.
Novel Cyclization of Vinyl Nitrene into 1-Azaphenalene
Authors: Isomura Kazuaki , Sakurai Makoto , Komura Toshio , Saruwatari Masumi , Taniguchi Hiroshi
Published: July 2006

Thermal reaction of 2H-azirines, bearing a methoxy or methylthio group at the neighboring position to azirine ring, was studied. In thermolysis of ethyl 2-(2-methoxynaphth-1-yl)-2H-azirine-3-carboxylate, attack of the vinyl nitrene at the peri position to form a 1-azaphenalene ring was observed. In thermal reaction of its thio analogue, 1-azaphenalene was also formed, but a naphthothiazine formed by the attack of vinyl nitrene at the sulfur atom was the major product. Mechanisms and differences of the reactions depending on O and S are discussed.
Synthesis of α-Arylated Phenylsulfonylacetonitriles. A Useful Precursor for Substituted α-Arylalkanoic Acid and Their Derivatives
Authors: Suzuki Hitomi , Yi Qui , Inoue Junko , Kusume Kumiko , Ogawa Takuji
Published: July 2006

Copper(I) iodide-catalyzed reaction of aryl iodides with anion derived from phenylsulfonylacetonitrile in hot hexamethylphosphoric triamide affords α-arylated nitriles in good to moderate yields. Further alkylation of these nitriles followed by reductive removal of sulfonyl group provides a simple route to α-arylalkanenitriles.
Stereoselectivity in Oxidative and Reductive Transformations of p-Menthane Derivatives with the Cultured Cells of Nicotiana tabacum
Authors: Suga Takayuki , Hamada Hiroki , Hirata Toshifumi , Izumi Shunsuke
Published: July 2006

The biotransformation of the enantiomeric pairs of 2- and 3-oxygenated p-menthane derivatives with the cultured cells of Nicotiana tabacum was investigated. It was found that (i) the cultured cells transform only 2-oxygenated p-menthane derivatives to a great extent, (ii) the cultured cells cause the highly stereospecific reduction for (1R,4R)-2-oxo-p-menthane, whereas this is not the case for its enantiomer, and (iii) the cultured cells enantioselectively oxidize the hydroxyl group of 2-hydroxy-p-menthanes.
Amplified Image Recording in Liquid Crystal Media by Means of Photochemically Triggered Phase Transition
Authors: Tazuke Shigeo , Kurihara Seiji , Ikeda Tomiki
Published: July 2006

Over 100 times amplified image recording was achieved by means of reading out nematic isotropic phase transition of liquid crystal induced by partial trans→cis photoisomerization of a small amount(up to 5 mol%) of 4-butyl-4′-methoxyazobenzene mixed with 4-cyano-4′-n-pentylbiphenyl.
A New Method of Formation of 9-Azabicyclo[4.2.1]nonane Skeleton and Its Application to Synthesis of (±)-Anatoxin a
Authors: Shono Tatsuya , Matsumura Yoshihiro , Uchida Kenshi , Tagami Katsumi
Published: July 2006

9-Azabicyclo[4.2.1]nonane skeleton was formed in one step by Lewis acid promoted reaction between 1-methoxycarbony1-2,5-dimethoxypyrrolidine and 1-ethoxy-1-trimethylsiloxy-1,4-pentadiene, and it was converted to (±)-anatoxin a.
Structural and Electrical Properties of (BEDT-TTF)3CuBr3
Authors: Mori Takehiko , Sakai Fumiko , Saito Gunzi , Inokuchi Hiroo
Published: July 2006

An organic conductor (BEDT-TTF)3CuBr3 (BEDT-TTF: bis(ethylenedithio)tetrathiafulvalene) crystallizes in the monoclinic space group P21/c, a = 16.937(3), b = 10.123(1), c = 14.178(4) Å, β=102.59(2)°, V = 2372.2(9) Å3, and Z = 2. The donors form a two-dimensional network, in which a charge separation takes place as (D3⁄4+D3⁄4+D0)2CuBr2−CuBr42−. The resistivity at room temperature is 0.6 Ωcm and semiconductive.
A Facile Synthesis of γ-Alkylidene-α,β-unsaturated γ-Lactones
Authors: Tsuboi Sadao , Wada Hiroshi , Mimura Shigetoshi , Takeda Akira
Published: July 2006

Treatment of β-allenic acid with KI3 gave directly γ-alkylidene-α,β-unsaturated γ-lactones in moderate yields.
A Convenient Preparation of α-Oxo Ketene Dithioacetals
Authors: Nakayama Juzo , Sugie Yasuko , Hoshino Masamatsu
Published: July 2006

The reaction of a series of ketones with 2 equiv. of 1,3-benzodithiolylium tetraf luoroborate affords α- (1, 3-benzodithiol-2-ylidene)ketones and 1,3-benzodithiole in good yields.
High Pressure Reaction of 1-Methoxy-3-trialkylsiloxybuta-1,3-diene with Aldehydes. [4 + 2] Cycloaddition or Silicon Migration Reaction
Authors: Yamamoto Yoshinori
Published: July 2006

The high pressure reaction of Danishefsky’s diene with aromatic aldehydes produces the [4 + 2] cycloadduct, while with an aliphatic aldehyde such as 2-phenylpropionaldehyde the intermolecular silicon migration from oxygen to oxygen takes place.
Calixarene-Based Amide Ionophores for Group IIA Metal Cations
Authors: Chang Suk-Kyu , Kwon Se-Ki , Cho Iwhan
Published: July 2006

Amide function-containing oligopodands synthesized from calixarenes exhibited characteristic selectivities toward Group IIA cations over Group IA cations in solvent extraction.
Electrochemical Determination of Electroinactive Medicines with Nafion-Coated Electrodes
Authors: Matsue Tomokazu , Aoki Atsushi , Uchida Isamu , Osa Testuo
Published: July 2006

Amperometic determination of electroinactive medicines (acetylcholine, hexamethonium, neostigmine, quinidine and nicotine) based on partition effect has been successfully performed with a Nafion-coated electrode.
Copper(II) Catalyzed Cyclization of Azidoalkadienylquinones. Stereoselective Formation of Dihydropyrroloindoloquinones and the Related Quinolinoquinone
Authors: Maruyama Kazuhiro , Nagai Naoshi , Naruta Yoshinori
Published: July 2006

Copper (II) salt catalyzed reaction of 2-azido-1,4-quinones with a conjugated alkadienyl side chain stereoselectively gave dihydropyrroloindoloquinones or dihydropyrroloquinolinoquinones, both of which are hardly obtained by uncatalyzed pyrolyses or photochemical reactions.
Asymmetric Reduction of α-Methylene Ketones by Using Fermenting Baker’s Yeast. Preparation of Optically Active β-Hydroxy α-Methyl Ketones
Authors: Utaka Masanori , Onoue Shinji , Takeda Akira
Published: July 2006

Asymmetric reduction of 4-hydroxy-3-methylenealkan-2-ones with baker’s yeast afforded (3R,4S)-4-hydroxy-3-methylalkan-2-ones in >98% ee and the (3R,4R) isomers in 67→98% ee in ratios of 1:1–2.
Synthesis of the Solid Superacid of SO42−/SnO2 with Acid Strength of Ho≤−16.04
Authors: Matsuhashi Hiromi , Hino Makoto , Arata Kazushi
Published: July 2006

A solid superacid catalyst with an acid strength of Ho≤−16.04 was synthesized from tin hydroxide, which was obtained from the solution with pH=10, by exposing to 3 mol·1−1 H2SO4 followed by calcination in air at 823 K; the catalyst was active for the skeletal isomerization of butane to isobutane at room temperature.
Electron Transfer Reaction between Fe4S4 Cluster and Methyl Viologen
Authors: Kitajima Nobumasa , Noda Sumio , Aono Shigetoshi , Okura Ichiro , MORO-OKA Yoshihiko
Published: July 2006

The reduction of Fe4S42+ to Fe4S41+ with the reduced form of methyl viologen, was found to proceed with the synthetic clusters ligated with pentafluorobenzenethiolate.
Organized Photodimerization of Cinnamic Acid in Cationic Reversed Micelle
Authors: Takagi Katsuhiko , Fukaya Haruhiko , Miyake Nobuhisa , Sawaki Yasuhiko
Published: July 2006

Laurylamine cinnamate salt (1), a reversed micelle-forming surfactant, undergoes a regioselective photodimerization to give syn-and anti-head-to-head dimers, the former being predominant. The rate of dimer formation shows a discontinuous point at the cmc of 1 (i.e., 3–5 mM), which is in parallel with the change in the relative emissive intensities of the monomer and the excimer.
Valence State of Copper Atoms and Transport Property of an Organic Superconductor, (BEDT-TTF)2Cu(NCS)2, Measured by ESCA, ESR, and Thermoelectric Power
Authors: Urayama Hatsumi , Yamochi Hideki , Saito Gunzi , Sugano Tadashi , Kinoshita Minoru , Inabe Tamotsu , Mori Takehiko , Maruyama Yusei , Inokuchi Hiroo
Published: July 2006

ESCA, ESR, and thermopower were measured in crystals of an organic superconductor, (BEDT-TTF)2Cu(NCS)2 (Tc=10.4 K), to examine a valence state of Cu and a transport property. The Cu state was confirmed at 298 K by ESCA. ESR indicates a broad Lorentzian signal of a BEDT-TTF cation radical and no Cu signal at 298–4 K. The thermopower is anisotropic in the two-dimensional bc plane, which is originated from the anisotropy of the band structure.
Crystal Structure of 2,5-Bis(dicyanomethylene)-2,5-dihydrothieno[3,2-b]thiophene and Bis(ethylenedithio)tetrathiafulvalene Complex
Authors: Aso Yoshio , Yui Koji , Ishida Hideki , Otsubo Tetsuo , Ogura Fumio , Kawamoto Atsushi , Tanaka Jiro
Published: July 2006

The crystal structure of 2,5-bis(dicyanomethylene)-2,5-dihydrothienot [3,2-b]thiophene and bis(ethylenedithio) tetrathiafulvalene complex showed a weak face to face interaction and sheet-like networks with intermolecular N···S and S···S interactions, and the shortest S···S contact is 3.48 Å between the acceptors.
The Addition Reaction of Acetals to Activated Olefins under Extremely Mild Conditions
Authors: Mukaiyama Teruaki , Wariishi Koji , Saito Yoshikazu , Hayashi Masaji , Kobayashi Shu
Published: July 2006

In the presence of catalytic amounts of trimethylsilyl chloride and tin(II) chloride, or trityl chloride and tin(II) triflate, activated olefins smoothly react with acetals to afford the corresponding adducts in good yields.
1-Benzyl-2,6-dicyanopiperidines as a New Class of Annelating Reagents. Use for Preparation of Fused Polycyclic Compounds
Authors: Takahashi Kazumasa , Asakawa Mikio , Ogura Katsuyuki
Published: July 2006

The utility of 1-benzyl-2,6-dialkyl-2,6-dicyanopiperidines as an annelating reagent, i.e. latent 1,5-diketones, is demonstrated in synthesis of multi-fused compounds.
Direct Optical Resolution of Carboxylic Acids by Chiral HPLC on Tris(3,5-dimethylphenylcarbamate)s of Cellulose and Amylose
Authors: Okamoto Yoshio , Aburatani Ryo , Kaida Yuriko , Hatada Koichi
Published: July 2006

A variety of racemic carboxylic acids have been for the first time directly resolved by normal-phase, high-performance liquid chromatography using a hexane-2-propanol eluting system containing a small amount (≈1%) of a strong carboxylic acid, like formic acid, trichloroacetic acid, and trifluoroacetic acid.
Polymerization of Monomers Containing Two Ethynyldimethylsilyl Groups
Authors: Kusumoto Tetsuo , Hiyama Tamejiro
Published: July 2006

Polymerization of (HC≡CSiMe2)2X with WCl6 or MoCl5 catalyst afforded polymers soluble in common organic solvents. The conductivity of the polymer fell in the range of insulators but was improved to 10−2 S·cm−1 upon doping with (Et2N) 3S+ SiF2Me3− (or n-Bu4N+ F−) and I2 (or SO3).
NMR Evidence for Ethyl Cation and Protonated Ethanol in the Pseudoliquid Phase of H3PW12O40
Authors: Lee Kwan Young , Kanda Yuji , Mizuno Noritaka , Okuhara Toshio , Misono Makoto , Nakata Shin-ichi , Asaoka Sachio
Published: July 2006

In the pseudoliquid phase of H3PW12O40, an ethyl cation and two protonated ethanol species (monomer and dimer) have been detected by solid-state MAS NMR of 1H, 13C, and 31P; these species are most probable reaction intermediates of dehydration of ethanol.
Extensively Conjugated Homologues of Selenophene-TCNQ as New Electron Acceptors
Authors: Yui Koji , Aso Yoshio , Otsubo Tetsuo , Ogura Fumio
Published: July 2006

5,5′-Bis(dicyanomethylene)-5,5′-dihydro-2,2′-biselenophene, its 3,3′-dibromo derivative, and 5,5″-bis(dicyanomethylene)-5,5″-dihydro-2,2′:5′,2″-terselenophene have been synthesized as extensively conjugated homologues of selenophene-TCNQ. The 3,3′-dibromo compound posseses a considerably better accepting character than selenophene-TCNQ or the other extended homologues and can form highly conductive molecular complexes.
Glucose Oxidase-Modified SnO2 Electrode as Electrochemical Glucose Sensor
Authors: Watanabe Tadashi , Okawa Yusuke , Tsuzuki Hirohiko , Yoshida Shoichiro , Nihei Yoshimasa
Published: July 2006

Glucose oxidase was chemically immobilized on an SnO2 electrode via 1) 2,4,6-trichloro-1,3,5-triazine, 2) 3-aminopropyltriethoxysilane and glutaraldehyde, or 3) crosslinkage of enzyme molecules by glutaraldehyde. These enzyme-immobilized electrodes were compared regarding the performance as amperometric glucose sensors.
Preparation of Novel Electron-Accepting Quinone Methide Imines and Their Polymerizations
Authors: Iwatsuki Shouji , Itoh Takahito , Itoh Hiromu
Published: July 2006

N,7,7-Tricyanoquinone methide imine (1), N,11,11-tricyano-1,4-naphthoquinone methide imine (2), and N,15,15-tricyano-9,10-anthraquinone methide imine (3) were successfully prepared as novel electron-accepting quinone methide imine compounds. 1 is homopolymerizable with free radical and anionic initiators, while 2 and 3 are not.
Effects of Sensitizer Spin Multiplicity on Electron-Transfer Initiated Isomerization of cis-Stilbene
Authors: Kuriyama Yasunao , Arai Tatsuo , Sakuragi Hirochika , Tokumaru Katsumi
Published: July 2006

The excited singlet and triplet states of 2,4,6-triphenylpyrylium were quenched by cis- and trans-stilbene to generate their radical cations; however, isomerization of stilbene occurred through radical cations only when the triplet state of the sensitizer was quenched by the cis isomer.