bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and Properties of 8H-3-Oxaheptalen-8-one
Authors: Nakazawa Tomoo , Ishihara (nee,Ashizawa) Mariko , Jinguji Mamoru , Yamaguchi Masakazu , Yamochi Hideki , Murata Ichiro
Published: July 2006

An ethanol solution of 12-oxatricyclo[7.2.1.02,8]dodeca-2(8),3,6,10-tetraen-5-one was irradiated with a 100-W Hg lamp through pyrex filter to give 8H-3-oxaheptalen-8-one, an oxepine condensed with tropone, in good yield together with a slight amount of 6-hydroxyazulene.
Efficient Synthesis of 2α-Glycoside of N-Acetylneuraminic Acid via Phenylsulfenyl Chloride Adduct of 2-Deoxy-2,3-dehydro-N-acetylneuraminic Acid Methyl Ester Tetra-O-acetate
Authors: Kondo Tadao , Abe Hiroyuki , Goto Toshio
Published: July 2006

Phenylsulfenyl chloride adds to a 2-deoxy-2,3-dehydro-N-acetylneuraminic acid derivative to give predominantly the corresponding 2-chloro-3β-phenylthio derivative, which is an excellent glycosyl donor for the preparation of α-glycosides of sialic acid.
Special Features of Stable Free Radical Formation on Plasma-irradiated α-d-Glucose Studied by ESR Spin-Trapping Technique
Authors: Kuzuya Masayuki , Washino Kaei , Noguchi Akihiro , Ito Akiko
Published: July 2006

The structure of the stable free radicals produced in argon plasma-irradiated α-d-glucose was characterized by the ESR spectral measurements of the spin adducts obtained from the reactions with 2,4,6-tri-t-butylnitrosobenzene (BNB) with the aid of computer simulations.
Convenient Synthesis of Hex-5-enopyranosides
Authors: Sato Ken-ichi , Kubo Noriyuki , Takada Rituko , Aqeel Amjad , Hashimoto Hironobu , Yoshimura Juji
Published: July 2006

Hex-5-enopyranosides were prepared in an one-pot procedure from 6-bromo-6-deoxy- or 6-O-tosylhexopyranoside by the successive treatment with iodide anion and 1,8-diazabicyclo-[5.4.0]undec-7-ene in DMSO.
Alkyl Transfer in the Heterodinuclear Organometallic Complex. Preparation of Organo(1,5-cyclooctadiene)platinum-tricarbonyl(cyclopentadienyl)tungsten
Authors: Komiya Sanshiro , Endo Isao
Published: July 2006

Methyl(1,5-cyclooctadiene)platinum-tricarbonyl(cyclopentadienyl) tungsten has been prepared by the reaction of methylchloro(1,5-cyclooctadiene)platinum(II) with sodium tricarbonyl-(cyclopentadienyl)tungstate(0). Methyl transfer from platinum to tungsten smoothly takes place on thermolysis as well as by the reaction with tertiary phosphine ligands, CO, or olefins.
Enzyme-catalyzed Asymmetric Hydrolysis of meso-Substrate. The Facile Synthesis of Both Enantiomers of cis-2,5-Disubstituted Tetrahydrofuran Derivatives
Authors: Naemura Koichiro , Takahashi Nobuo , Chikamatsu Hiroaki
Published: July 2006

The enzyme-catalyzed asymmetric hydrolysis of the meso-diesters derived from cis-2,5-bis(hydroxymethyl)tetrahydrofuran in presence of PLE, PPL, and CCL afforded the optically active half-esters. The both enantiomers of cis-5-(hydroxymethyl)tetrahydrofuran-2-carboxylic acid with high optical purity were prepared from the half-esters.
One-Pot Synthesis of α-Mono- and α,α-Disubstituted Cyclic Ethers from Lactones
Authors: Mukaiyama Teruaki , Homma Koichi , Takenoshita Haruhiro
Published: July 2006

α-Mono- and α,α,-disubstituted cyclic ethers are prepared in good yields by the successive treatment of lactones with t-butyldimethylsiloxy-1-ethoxyethene and silyl nucleophiles (triethylsilane, allyltrimethylsilane, trimethylsilyl cyanide, etc.) in the presence of a catalytic amount of trityl salts such as TrSbCl6, TrSbF6 and TrClO4 or antimony pentachloride combined with chlorotrimethylsilane and tin(II) halide.
Spectral Evidences for the J-Aggregate Formation of a Non-Benzenoid Aromatic Dye, Dicyclohepta[5,6:b]pyrazino[2,3-g]quinoxaline-3,11-dione
Authors: Takeshita Hitoshi , Mori Akira , Nagao Tomohiro , Nagamura Toshihiko
Published: July 2006

The planar and symmetrically conjugated π-system, dicyclohepta[5,6:b]pyrazino[2,3-g]quinoxaline-3,11-dione, showed a narrow and intense absorption band and resonance fluorescence in cone H2SO4 solutions as low as 10−7 M. These observations show the formation of the J-aggregate. A remarkable solvatochromism was also noticed in organic solvents (476 nm in CHCl3 and 547 nm in DMF).
Application of Host–Guest Complexation Method to Isolation of Natural Product
Authors: Segawa Mari , Mori Koji , Toda Fumio
Published: July 2006

Application of host–guest complexation method to isolation of caffeine, nicotine, and cholesterol from tea and tabaco leaves, and gallstone, respectively, has been reported. Separations of strychnine and brucine, and sparteine and brucine by the same method were also reported.
Catalytic Activity of an Octopus-type Calixarene on the Formation of Ethers
Authors: Taniguchi Hisaji , Nomura Eisaku
Published: July 2006

5,11,17,23,29,35-Hexa-p-tert-butyl-37,38,39,40,41,42-hexakis-(3,6,9-trioxadecyloxy)calix [6]arene catalyzes the formation of an ether and bisphenoxymethanes through the Williamson synthesis.
Direct Synthesis of τ-Form Metal-Free Phthalocyanine from Phthalodinitrile by Seeding Procedure
Authors: Enokida Toshio , Ehashi Shigeyuki
Published: July 2006

Direct synthesis of τ-form metal-free phthalocyanine (τ-H2Pc) was performed from phthalodinitrile by using of 1,8-diaza-bicyclo(5,4,0)undecene-7 (DBU) and crystal nucleus in alcohol.

The yield of τ-H2PC was investigated under various conditions.
Photoelectrochemical Properties of TiO2 Microcrystallites Incorporated in Sheet Silicates of Montmorillonite
Authors: Yoneyama Hiroshi , Nippa Satoru
Published: July 2006

Photoelectrochemical properties of the titled material were investigated in a system of clay-modified electrodes. Photocurrent action spectra of the incorporated TiO2 microcrystallites having ca. 15 Å diameter showed a blue shift from those of a TiO2 single crystal electrode, indicating the operation of the quantum size effect at the TiO2 microcrystallites. Photoelectrochemical activities for oxidation of several aliphatic alcohols were a little higher at the TiO2 microcrystallites incorporated in the clay than the TiO2 single crystal.
Photoluminescence Proof of the Increase of Surface Recombination Velocity at p-GaAs Electrode by Pt Treatment
Authors: Uosaki Kohei , Shigematsu Yasuyuki , Kita Hideaki
Published: July 2006

Photoluminescence measurements with excitation light of several wavelengths were employed to investigate the effect of noble metal treatment on hydrogen evolution reaction at semiconductor electrode. It was demonstrated that surface recombination velocity was increased by Pt treatment leading to higher dark current and lower photocurrent.
Substituent Effects in 9,10-Dihydro-9,10-o-benzenoanthracene-1,4-diones on the Half-wave Potentials
Authors: Yamamura Kimiaki , Miyake Hideyoshi , Himeno Sadayuki , Inagaki Satoshi , Nakasuji Kazuhiro
Published: July 2006

Polarographic half-wave reduction potentials of some 9,10-dihydro-9,10-o-benzenoanthracene-1,4-diones showed that methoxy group is less electron donating than methyl group. Observed substituent effects are successfully discussed in terms of the inductive effect, the intramolecular LUMO-LUMO interaction, the LUMO amplitudes, and so on.
Square Planar–Octahedral Equilibrium of Bismacrocyclic Ni(II)Ni(II) Complexes with a Polymethylene Bridge of Various Lengths
Authors: Mochizuki Katsura , Iijima Asako , Endoh Yumiko
Published: July 2006

Bismacrocyclic Ni(II)Ni(II) complexes, i.e., 7,7′-polymethylenebis[2,12-dimethyl-3,7,11,17-tetraazabicyclo[11.3.1]heptadeca-1(17),2,11,13,15-pentaene]dinickel(II) perchlorates with polymethylene bridges of 2-6-C length, exist in the equilibrium between square planar and octahedral forms in water. The equilibrium shifts toward the octahedral side as the polymethylene bridge is shortened.
Cyclic Voltammetric Investigation of Disilenes
Authors: Shepherd Brian D , West Robert
Published: July 2006

Three tetraaryldisilenes and two dialkyldiaryldisilenes were investigated by cyclic voltammetry, all undergoing irreversible oxidation and reduction. The oxidation potentials were similar for all five compounds, but the reduction potentials were lower for the tetraaryldisilenes than for the dialkyldiaryldisilenes.
Regioselective Liquid-Phase Toluene Nitration with Modified Clays as Catalysts
Authors: Cornelis André , Gerstmans André , Laszlo Pierre
Published: July 2006

Catalytic mononitration of toluene (yields of 50–81%; turnover at least 850) occurs in the presence of modified clays with useful regioselectivities, such as (o:m:p) = 31:2:67. The nitrating species is extracted from concentrated nitric acid by carbon tetrachloride-acetic anhydride mixture.
Structure and Reactivity Studies of 5-Methyl-1,5-dihydro-5-deazaisoalloxazinophane
Authors: Shinkai Seiji , Nishiyama Noriaki , Matsuda Tsutomu , Kanazawa Ryusuke , Kawase Akito , Manabe Osamu
Published: July 2006

The X-ray structure analysis established that in the reaction of 5-deazaisoalloxazinophane and MeMgBr the methyl group is incorporated into the axial C(5) position. The axial selectivity is in line with the stereochemical course observed for the reduction of this compound. The product having only Heq at C(5) is much less reactive than 1,5-dihydro-5-deazaisoalloxazinophane having both Heq and Hax.
Laser Ablation-Molecular Beam Method: A Versatile Diagnosis for the Reactions of Metal Ions with Molecules in the Gas Phase. Dimanganese Decacarbonyl
Authors: Oka Tadashi , Toya Kenzo , Kasatani Kazuo , Kawasaki Masahiro , Sato Hiroyasu
Published: July 2006

Intense laser light was focussed on the surface of a metal substrate (Nb or Cu) in vacuum, and a molecular beam of Mn2(CO)10 was injected nearby. Product ions resulting from the reaction of substrate metal ions or electrons with Mn2(CO)10 were analyzed by mass-spectroscopy. This method provides a simple and versatile diagnosis for the reactions of metal ions and/or electrons with molecules in the gas phase.
A Water-Stable Quadricyclane Derivative
Authors: Tamiaki Hitoshi , Maruyama Kazuhiro
Published: July 2006

A quadricyclane derivative stable in water was first synthesized. Valence isomerization between the quadricyclane and the corresponding norbornadiene was very clean, to be promising for a solar energy storage system.
A New Route to Perfluorovinylamines by the Pyrolytic Reaction of an Alkali Metal Salt of Perfluoro(2-dialkylamino-propionic acids)
Authors: Abe Takashi , Hayashi Eiji
Published: July 2006

A potentially general route to various kinds of perfluorovinylamines is described involving a pyrolysis of an alkali metal salt of perfluoro(2-dialkylamino-propionic acids)
Electrically Induced Wettability Change of Polyaniline. Potential Controlled Tensiometric Study
Authors: Hato Masakatsu
Published: July 2006

Electrically induced wettability change of polyaniline has been addressed by a potential controlled tensiometric method. Contact angle decreases with a change in the electrical potential toward more positive values. Wettability of polyaniline can be modulated by external electrical signals.
Synthesis and X-Ray Structure Analysis of Novel Ethyl-Bridged Ytterbium–Triethylaluminum Complex; (η-C5Me5)2Yb·Al(C2H5)3 (THF)
Authors: Yamamoto Hitoshi , Yasuda Hajime , Yokota Kiyohiko , Nakamura Akira , Kai Yasushi , Kasai Nobutami
Published: July 2006

A series of novel ytterbium–organoaluminum complexes has been prepared by the reaction of YbCp*2 (THF) (Cp*=η-C5Me5) with AlR3. The X-ray structure analysis of the triethylaluminum complex, YbCp*2Al(C2H5)3 (THF), revealed the presence of unusual Yb–(μ-C2H5)–Al linkage. The complex catalyzes the polymerization of ethylene, methyl methacrylate and styrene in toluene.
An Efficient Synthesis of Benzothiazole Derivatives of Thiosugars under Phase-Transfer Conditions
Authors: Bogusiak Jadwiga , Szeja Wieslaw
Published: July 2006

2-Benzothiazole derivatives of thiosugars can be conveniently prepared by treatment of reducing monosaccharides with tosyl chloride and 2-mercaptobenzothiazole under phase-transfer conditions.
A Radical Substitution on Sulfur of Thioester Group. Formation of β- and γ-Thiolactone
Authors: Tada Masaru , Matsumoto Mitsuhiro , Nakamura Tatsuya
Published: July 2006

Alkyl radicals having (t-butylthio)carbonyl group on β- or γ-position gave β- or γ-thiolactones whereas the homologous radical did not give δ-thiolactone. These reactions involve intramolecular radical substitution on the sulfur atom of thioester group. Ethylthioesters have much less reactivity to the same substitution.
Facile Synthesis, Crystal Structure, and Oxidizability of a Novel Benzene Tris-Annelated with Bicyclo[2.2.2]oct-2-ene
Authors: Komatsu Koichi , Jinbu Yasuhisa , Gillette Gregory R , West Robert
Published: July 2006

Trimerization of 2,3-dibromobicyclo[2.2.2]oct-2-ene by the use of butyllithium followed by subsequent cyclization gives 1,2:3,4:5,6-tris(bicyclo[2.2.2]oct-2-eno)benzene (3), the highly symmetrical structure of which is established by X-ray crystallography. Compound 3 is reversibly oxidized upon cyclic voltammetry at 1.25 V vs Ag/Ag+ in CH3CN.
Control of Chemical Selectivity by Specific Weak Interactions between Groups in Reacting Molecules
Authors: Endo Tadashi , Suzuki Takashi , Nakajima Yutaka , Sakiyama Yutaka , Takami Kunihiko , Kato Jun-ichi
Published: July 2006

In oxidation of a pair of associating thiols, each having a phenyl or a given group (R), it has been found that the order of the selectivity agrees with that of the strength of specific R–Ph interactions for each of two sets of R [(i) p-MeC6H4 < Ph < p-MeOC6H4 and (ii) n-C5H11 < Ph < p-MeCOC6H4].
Allylation of Aldehydes in an Aqueous Two-phase System by Electrochemically Regenerated Bismuth Metal
Authors: Minato Makoto , Tsuji Jiro
Published: July 2006

Aldehydes are allylated efficiently by the catalysis of BiCl3 in a two-phase electroreductive system.
Photothermal Spectrometry Using Pyroelectric Sensor
Authors: Hinoue Teruo , Kawada Satoshi , Murata Mitsuhiro , Yokoyama Yu
Published: July 2006

Temperature change of a sample solution due to optical absorption was detected by a pyroelectric sensor. A calibration curve was linear at the low concentrations of dye and the detection limit was 0.0035 cm−1. From a solvent dependence of the signal magnitude, the signal generation could be explained by thermal conduction.
Generation of Organic Cations from Group 14 Organometallic Compounds via Photoinduced Electron Transfer in the Presence of Cu(II) Salt
Authors: Mizuno Kazuhiko , Yasueda Masahiro , Otsuji Yoshio
Published: July 2006

Irradiations of acetonitrile-alcohol (3 : 1) solutions of arylmethyl silanes, germane, or stannanes in the presence of Cu(BF4)2 gave alkyl arylmethyl ethers in good yields via arylmethyl cations. The efficiency of this photoreaction increased in the order of Si- < Ge- < Sn-compounds.
Facile Preparation of Manganese(II) Tetraphenylporphyrin by the Pyrolysis of Dimethoxoraanganese(IV) Tetraphenylporphyrin
Authors: Suzuki Toru , Imamura Taira , Fujimoto Masatoshi
Published: July 2006

Manganese(II) tetraphenylporphyrin, MnII (tpp) (tpp = meso-tetraphenylporphinato), was afforded by the pyrolysis of MnIV(tpp)(OCH3)2 at ≈180 °C under 10−4–10−5 Torr (1 Torr ≅ 133.3 Pa). The pyrolysis of MoVO(tpp)OR (R = CH3, C2H5) in the solid state yielded MoIVO(tpp).
Superconducting Oxide Thin Films Prepared by Sol–Gel Technique Using Metal Alkoxides
Authors: Monde Takashi , Kozuka Hiromitsu , Sakka Sumio
Published: July 2006

Superconducting oxide thin films of the YBa2Cu3Ox system have been prepared on zirconia (YSZ) substrates by sol–gel technique using metal alkoxide solution. Yttrium butoxide, barium methoxide and copper methoxide in a given atomic ratio were dissolved in a triethanolamine–methanol solution. Coating of the resultant solution, heating at 800 °C in air and annealing in an oxygen atmosphere resulted in superconducting oxide thin films. The onset of superconductivity was seen at 98 K and the resistance rapidly decreased with decreasing temperature, reaching substantially zero at 56 K.
Allylation of Active Methylene Compounds with Allyl Oxime Carbonates Catalyzed by Pd(0)
Authors: Suzuki Osamu , Hashiguchi Yoshiharu , Inoue Seiichi , Sato Kikumasa
Published: July 2006

Allylation of active methylene compounds catalyzed by a palladium(0)-phosphine system took place highly stereoselectively by employing allyl oxime carbonates as the allylating reagent.
Low-temperature and Direct Synthesis of Ethanol from Ethane and Water by the Photochemical Reaction
Authors: Ogura Kotaro , Arima Hiroaki
Published: July 2006

Ethane is directly converted to ethanol by the photochemical reaction at temperatures lower than 100 °C in atmospheric pressure. The conversion reaction is initiated by the hydroxyl radicals formed in the photolysis of water vapor. The conversion coefficient of ethane was 7.7% at 5h, and the selectivity 33.3%.
C-2 Epimerization of Disaccharides by Nickel(II)–Diamine Complex. A New Synthesis of (1→6)-Linked Disaccharides Having Mannose as a Reducing Unit
Authors: Tanase Tomoaki , Ishida Katsuaki , Watanabe Tadashi , Komiyama Makoto , Koumoto Kunihito , Yano Shigenobu , Hidai Masanobu , Yoshikawa Sadao
Published: July 2006

(1→6)-Linked disaccharides having mannose as a reducing unit were synthesized from their naturally abundant C-2 epimers by the novel C-2 epimerization promoted by nickel(II)-diamine complex, [Ni(H2O)2(tmen)2]Cl2 (tmen = N,N,N′-trimethylethylenediamine).
σ(Si–Si)-π Intramolecular Charge–Transfer Interaction and X-Ray Structure of 4-Dicyanomethylene-1-silylsilacyclohexanes
Authors: Kira Mitsuo , Takeuchi Kiyoshi , Kabuto Chizuko , Sakurai Hideki
Published: July 2006

4-Dicyanomethylene-1-trimethylsilylsilacyclohexane (2a) and the trisilane analog (2b) showed the intramolecular CT bands in the absorption spectra. In combination with the results of the X-ray structure analysis of 2a, the origin of the σ(Si–Si)-π CT interaction was ascribed to the through-bond orbital interaction.
Fe3O(OAc)6(Py)3 Mediated Reduction of Aromatic Nitro Compounds with 2-Mercaptoethanol
Authors: Murata Satoru , Miura Masahiro , Nomura Masakatsu
Published: July 2006

Aromatic nitro compounds were selectively reduced by 2-mercaptoethanol in the presence of Fe3O(OAc)6(Py)3 to give the corresponding amines in good yields.
Redox Photochromism Involving Near Infrared Absorption Maximum
Authors: Kamogawa Hiroyoshi , Nanasawa Masato
Published: July 2006

trans-4,4′-Vinylenebis (1-benzylpyridinium) dichlorides and 1,1′-ethylene-2,2′-bipyridinium dibromides in a poly(N-vinyl-2-pyrrolidone) matrix film exhibited reversible absorption maxima in the near IR(ca. 800 nm) upon UV irradiation. The thermal stability of the absorption maximum thus developed was influenced by the surroundings as well as the kind of compound.
Simplified Chiral Aminolysis of Prochiral σ-Symmetric Dicarboxylic Anhydrides with Sodium Salt of 4(S)-IPTT
Authors: Nagao Yoshimitsu , Hagiwara Yuichi , Hasegawa Yukari , Ochiai Masahito , Inoue Takehisa , Shiro Motoo , Fujita Eiichi
Published: July 2006

Highly enantioselective chiral aminolysis of cis-4-cyclo-hexen-1,2-ylenebis(carboxylic acid) anhydride has been performed by employing sodium salt of 4(R)-isopropyl-1,3-thiazolidine-2-thione in THF-DMSO. Other chiral aminolyses of prochiral σ-symmetric dicarboxylic anhydrides such as cis-cyclobutan-1,2-ylenebis(carboxylic acid) anhydride, meso-2,4-dimethylglutaric anhydride, and 3- [(t-butyldimethylsilyl) oxy] glutaric anhydride were similarly investigated.
Chiral α-Methyl-homoallylic Alcohols from Yeast-Generated Precursors. Synthesis of (4R,5S) Sitophilure
Authors: Fronza Giovanni , Fuganti Claudio , Högberg Hans-Erik , Pedrocchi-Fantoni Giuseppe , Servi Stefano
Published: July 2006

Optically active (3S,4R)-3,4-dihydroxy-4-methyl-6-phenyl-hex-5-ene and (2S,3RS)-2,3-dihydroxy-3-methyl-5-phenyl-pent-4-ene, previously obtained from fermenting baker’s yeast reduction of the corresponding Ketones, are transformed either into optically active α-ethyl and α-methyl ketones, or into α-methyl homoallylic alcohols from which enantiomerically pure (4S,5R) sitophilure, (2S,3R)-2-methyl-1,3-butandiol and its (2S,3S)-diastereoisomer have been prepared.
Chemical Reactions in Medium Density Fluids. Inversion of Density Dependence of the Dimerization Equilibrium of 2-Methyl-2-nitrosopropane in Carbon Dioxide
Authors: Kimura Yoshifumi , Yoshimura Yosuke , Nakahara Masaru
Published: July 2006

Pressure effect on the dimerization–dissociation reaction of 2-methyl-2-nitrosopropane was studied in supercritical carbon dioxide. The configurational volume change for the dimerization, which was negative at high density, was found to be positive in a medium density region.
The Friedel-Crafts Type Methanesulfonylation of Deactivated Benzenes
Authors: Ono Mitsunori , Nakamura Yoshisada , Sato Shingo , Itoh Isamu
Published: July 2006

The participation of nonionic donor-acceptor complex [A] was suggested by the analyses of product isolated in the Friedel–Crafts reaction of m-dichlorobenzene with CH3SO2Cl in the presence of AlCl3. On the basis of these observations a new practical method of methanesulfonylation of deactivated benzenes employing methane-sulfonic anhydride and CF3SO3H was developed.
An Electrochemical Fabrication Method for Gold and Carbon Ultramicroelectrode
Authors: Abe Takayuki , Itaya Kingo , Uchida Isamu
Published: July 2006

Au and carbon fiber ultramicroelectrodes have been fabricated by using an anodic electropolishing method. The radii of them were found to be about 450 nm on Au and 240 nm on carbon electrodes from the calculation based on the steady-state limiting currents.
SmI2-(Chiral Auxiliary)-Induced Asymmetric Reduction
Authors: Takeuchi Seiji , Ohgo Yoshiaki
Published: July 2006

Benzil was reduced to benzoin with 56.27% ee by a system of SmI2-THF-HMPA in the presence of quinidine.
Intercalation of Tetrathiafulvalene(TTF) into Montmorillonite by Reaction with the Interlayer Cations
Authors: Soma Mitsuyuki , Soma Yuko
Published: July 2006

Tetrathiafulvalene(TTF) is intercalated into montmorillonite through oxidation by the interlayer Cu2+ ion, in excess of the cation exchange capacity of the clay, forming mixed-valent aggregates. TTF cation can be also intercalated through cation exchange with the interlayer Na+ ion.
Uphill Transport of Dihydrogenphosphate Ion through a Liquid Membrane Containing Oxomolybdenum(V) Tetraphenylporphyrin Complex as a Mobile Carrier
Authors: Kokufuta Etsuo , Nobusawa Mitsuyuki
Published: July 2006

Oxomolybdenum(V) tetraphenylporphyrin complex is useful as a carrier for preparing a polymer-supported liquid membrane system in which H2PO4− ion is transported against its concentration gradient by coupling of a ligand exchange reaction.
Transfer Hydrocracking of Diphenylpropane with Tetralin on Active Carbon Catalysts
Authors: Nakamura Ikusei , Aimoto Kohjiroh , Fujimoto Kaoru , Tominaga Hiro-o
Published: July 2006

A nickel supported on active carbon catalyst was found to exhibit an excellent activity for transfer hydrocracking of diphenylpropane with tetralin at 400 °C. It is demonstrated that the catalytic transfer hydrogenation is effected by the reverse spillover of hydrogen atom over the active carbon.
Ruthenium Catalyzed N-Methylation of Aminoaranes Using Methanol
Authors: Huh Keun-Tae , Tsuji Yasushi , Kobayashi Masanobu , Okuda Fumio , Watanabe Yoshihisa
Published: July 2006

Methanol reacts with aminoarenes in the presence of a catalytic amount of ruthenium trichloride hydrate combined with tributylphosphite at 180 °C to give the corresponding N-methylaminoarenes in high yields.
Influence of an Axial Ligand in the Oxidation of the Nitrosyl Complex of Ruthenium(II), trans-[RuX(NO)(py)4]2+ (X=Cl, OH), to Give Oxo Complex of Ruthenium(IV)
Authors: Nishimura Hisatoshi , Nagao Hirotaka , Howell F Scott , Mukaida Masao , Kakihana Hidetake
Published: July 2006

Oxidation of trans-[Ru(OH)(NO)(py)4]2+ gives trans-[Ru(ONO)(O)(py)4]+, while that of trans-[RuCl(NO)(py)4]2+ yields trans-[RuCl(O)-(py)4]+. The two complexes differ in the origin of the oxo ligand. Their formation proceses were proved to be influenced by the ligand trans to the nitrosyl.
Photochromism of [2.n]Metacyclophan-1-ene Derivatives
Authors: Murakami Shin-ichi , Tsutsui Tetsuo , Saito Shogo , Miyazawa Akira , Yamato Takehiko , Tashiro Masashi
Published: July 2006

Photochromism of [2.n]metacyclophan-1-ene derivatives (n=2,3,4) was investigated. The reaction rates of the thermal decoloration were increased about thousand-fold with increasing of n by one.
Organoselenium-mediated Reduction of α, β-Epoxy Esters to β-Hydroxy Esters
Authors: Miyashita Masaaki , Hoshino Masahide , Suzuki Toshio , Yoshikoshi Akira
Published: July 2006

α, β-Epoxy esters were reduced to β-hydroxy esters with an organoselenium reagent, Na+[PhSeB(OEt)3]−, via α-substitution process.
Isolation of 2-Mercaptotropone as a 2:1 Complex with 1,1,6,6-Tetraphenylhexa-2,4-diyne-1,6-diol and X-Ray Crystal Structure of the Complex
Authors: Toda Fumio , Tanaka Koichi , Asao Toyonobu , Ikegami Yusaku , Tanaka Naoki , Hamada Kensaku , Fujiwara Takaji
Published: July 2006

Of two tautomers of 2-mercapto substituted tropone, 2-mercaptotropone and 2-hydroxytropothione, the former is isolated as a 2:1 complex with 1,1,6,6-tetraphenylhexa-2,4-diyne-1,6-diol, and infrared and electronic absorption spectra of the complex are reported. X-Ray crystal structural study shows that the 2-mercaptotropone in the complex has no bond alternation and then has a delocalized π-electron system.
Methyl and Aryl Ru(II) Complexes of Crown Thioethers, R4[14]aneS4 (R=Me, H) Remarkable Geometrical Effect on Intermolecular C(sp2)–H Bond Activation by cis- and trans-RuCl2R4 [14] aneS4–Al2Me6
Authors: Ueda Tatsuo , Yamanaka Hiroaki , Adachi Tomohiro , Yoshida Toshikatsu
Published: July 2006

A reaction of cis-RuCl2R4[14] aneS4 (R=Me, H) with Al2Me6 in aromatic hydrocarbons proceeds through an intermolecular C(sp2)–H bond activation affording trans-RuAr(Cl)R4[14]aneS4 (Ar=C6H4Me, C6H5), while a similar reaction of trans isomer gives trans-RuMe(Cl)Me4[14]aneS4.
Synthesis and Structure of Organodiselenogermanes
Authors: Tomoda Shuji , Shimoda Masakatsu , Takeuchi Yoshito , Iitaka Yoichi
Published: July 2006

Diphenylselenogermanes are prepared for the first time in 32–89% yield by the reaction between sodium benzeneselenolate and dihalogermanes (halogen=Cl or Br). The X-ray structure of 1,1-diphenylseleno-1-germacyclopentane has been determined.
Electrochemical Formation of Polymer Thin Films by Disruption of Micellar Complex
Authors: Hoshino Katsuyoshi , Goto Masayuki , Saji Tetsuo
Published: July 2006

Polymer thin films of poly(4-vinylpyridine), and copolymer of methyl methacrylate and methacrylic acid were prepared by electrolysis of an aqueous solution containing a surfactant with ferrocenyl moiety and corresponding polymer. The film thickness increased linearly with the amount of electricity. The morphology of the films was investigated by scanning electron microscopy.
Preparation of Superconducting YBa2Cu3O7−δ Films by the Dipping-Pyrolysis Process Using Metal Acetylacetonates
Authors: Kumagai Toshiya , Kondo Wakichi , Yokota Hiroshi , Minamiue Hidehiro , Mizuta Susumu
Published: July 2006

Superconducting YBa2Cu3O7−δ films were prepared on yttria stabilized zirconia substrates by the dipping-pyrolysis process using metal acetylacetonates (Y/Ba/Cu = 1.0/3.0/4.3) as starting materials; TC (onset) of 97 K and TC (end) of 89 K were achieved in the resistivity measurement for the films annealed at 950 °C in O2.
MAS-NMR Spectra of 23Na in Spinel Block of β- and β″-Alumina Structures
Authors: Ikawa Hiroyuki , Shima Koji , Urabe Kazuyori
Published: July 2006

The MAS-NMR spectra of the unexchangeable sodium in Na+- and K+-β″-gallates were sharp and symmetric, and their chemical shifts were far larger than that of sodium on the conduction planes. The results were consistent with the studies that the sodium ion could occupy the tetrahedral site in the middle of the spinel blocks.
Odd–Even Effect in the Optical Resolution by Optically Active Polyamides Having (−)-Anti Head-to-head Coumarin Dimer Component
Authors: Saigo Kazuhiko , Chen Yun , Fujioka Kazutoshi , Yonezawa Noriyuki , Hasegawa Masaki
Published: July 2006

Optically active polyamides were synthesized by ring-opening polyaddition reaction of (−)-anti head-to-head coumarin dimer with H2N–(CH2)n–NH2 (n=2–10). The polyamides show high optical resolution ability to racemates containing an aromatic group(s) when n is even number of 6 and over, while no resolution could be achieved when n is odd number.
Structure of Nigakilactone O, a New Quassinoid from Picrasma Ailanthoides
Authors: Hirota Hiroshi , Yokoyama Akihisa , Tsuyuki Takahiko , Takahashi Takeyoshi , Waelchli Markus
Published: July 2006

Nigakikactone O, a new picrasane-skeletal compound, was isolated from Picrasma ailanthoides PLANCHON, and its structure including the stereochemistry was determined to be 2α-hydroxy-12β-methoxy-11α-(3-methoxy-4,5-methylenedioxybenzoyloxy)picrasane-1,16-dione mainly by 1D and 2D NMR techniques.
Preparation of YBa2Cu3O7−δ Superconductor through Organornetallic Route
Authors: Hirano Shin-ichi , Hayashi Takashi , Baney Ronald H , Miura Masashi , Tomonaga Hiroyuki
Published: July 2006

The preparation of high Tc superconducting YBa2Cu3O7−δ compound was investigated through organometallic route, using Ba metal, Y(O–iPr)3 and Cu-alkoxides or Cu-acetylacetonate as starting materials. Chemically homogeneous submicron powder of orthorhombic YBa2Cu3O7−δ was prepared as a single phase by controlled partial hydrolysis of metal alkoxides. It was confirmed by dc resistivity and magnetic susceptibility measurements that single phase YBa2Cu3O7−δ ceramics exhibited superconductivity at about 90 K (Tc onset).
Application of Free Radical Substitution Reaction into Interconversion of 1-Alkenylsulfides, 1-Alkenylgermanes, and 1-Alkenylstannanes
Authors: Ichinose Yoshifumi , Oshima Koichiro , Utimoto Kiitiro
Published: July 2006

Treatment of 1-alkenylsulfides or 1-alkenylstannanes with Ph3GeH in the presence of Et3B provides 1-alkenyltriphenylgermanes in good yields. 1-Alkenylstannanes are converted into 1-alkenylsulfides easily with PhSH–Et3B, whereas 1-alkenyltriphenylgermanes are recovered unchanged upon treatment with Ph3SnH–Et3B or PhSH–Et3B.
Non-Catalyzed Cleavage Reactions of Ethers with Acyl Halides under High-Pressure Conditions
Authors: Kotsuki Hiyoshizo , Ichikawa Yoshikatsu , Nishizawa Hitoshi
Published: July 2006

Various cyclic and acyclic ethers are efficiently cleaved with acyl chlorides or bromides to give ω-chloro- or ω-bromoesters under high-pressure conditions.
C=C Double Bond Insertion in Catalytic C–H Activation. Dehydrogenative Cross Coupling of Arenes with Olefins
Authors: Sasaki Koushi , Sakakura Toshiyasu , Tokunaga Yuko , Wada Keisuke , Tanaka Masato
Published: July 2006

The reaction of benzene with methyl acrylate and ethylene catalyzed by RhCl(CO)(PMe3)2 under irradiation gave methyl cinnamate and styrene, respectively. The reaction of toluene afforded meta-substituted isomers as major products.
Stereospecific Cleavage of Adenosine 2′,3′-Cyclic Monophosphate Catalyzed by Cyclodextrins
Authors: Komiyama Makoto
Published: July 2006

Stereospecific cleavage of adenosine 2′3′-cyclic monophosphate to the 2′-monophosphate is achieved at pH 11.08, 20 °C by use of β-and γ-cyclodextrins as catalysts. The 2′/3′ ratio for the product is 7.7 at the concentration 1.5×10−2 mol dm−3 of β-cyclodextrin. In contrast, α-cyclodextrin promotes the formation of the 3′-monophosphate, giving the product 2′/3′ ratio 0.49 at the concentration 1.0×10−2 mol dm−3.
Electrochemical Formation of a Phthalocyanine Thin Film by Disruption of Micellar Aggregates
Authors: Saji Tetsuo
Published: July 2006

Phthalocyanine (1) was dissolved to the micellar solution formed by non-ionic surfactants with ferrocenyl moiety. A 1 thin film was prepared on an indium tin oxide (ITO) electrode by the controlled-potential electrolysis of this solution. This film consisted of rod-like crystals of 500 nm in length.
Photorearrangement of 4,4,5,5-Tetramethoxycyclohepta-2,6-dienones to 6,6,7,7-Tetramethoxybicyclo[3.2.0]hept-3-en-2-ones
Authors: Mori Akira , Kubota Tadahiko , Takeshita Hitoshi
Published: July 2006

The photorearrangement of 2,6-cycloheptadienones to bicyclo[3.2.0]hept-3-en-2-ones was observed. The bicycloketones further photoisomerized to bicyclo[2.2.1]heptenones via a [1,3] sigmatropy.
Ammonia-Hydrochloric Acid Equilibrium Product over Solid and Aqueous Ammonium Chloride at 25 °C
Authors: Hara Hiroshi
Published: July 2006

Relative humidity dependence of the equilibrium product of NH3 and HCl was thermodynamically calculated for ammonium chloride at 25 °C. This compound was found to be deliquescent at relative humidity greater than 77%, where the product began to decrease steeply. When the solution was treated as ideal, the product was mispredicted several factors higher than that for non-ideal solution.
Reactivity of α-Metal(group 4) Esters. Lewis Acid Mediated Reactions of α-Triphenyltin Esters with Aldehydes and Acetals
Authors: Kiyooka Syun-ichi , Nakata Masumi
Published: July 2006

Ethyl triphenylstannylacetate and ethyl α-triphenylstannylpropionate reacted with aldehydes and acetals to give β-hydroxy and β-alkoxy esters at room temperature in the presence of TiCl4, in moderate yields. Under these conditions ethyl triphenylgermylacetate and ethyl trimethylsilylacetate did not work.
A Novel [2+4] Photocyclization Reaction between Quinone and Allene
Authors: Maruyama Kazuhiro , Imahori Hiroshi
Published: July 2006

1,1-Diphenylallene underwent a [2+4] photocycloaddition reaction with the carbonyl group of 2,3-dichloro-1,4-naphthoquinone to produce a novel spiro compound.
Formation of [η5,η1–C5H4C (OCOR)=C(OCOR)CO]Fe(CO)2 Complexes via Triple CO Insertion into Cyclopentadienyl Anions by Fe(CO)5
Authors: Nakanishi Saburo , Hirano Takehiro , Otsuji Yoshio
Published: July 2006

The reaction of cyclopentadienyl anions with Fe(CO)5 in the presence of acyl chlorides gave [η5,η1–C5H4C (OCOR)=C(OCOR) CO] Fe(CO)2 complexes, accompaning a triple CO insertion into the anions and a double acylation.
The Crystal and Molecular Structures of 1:2 Complexes of N,N′-Dimethylpiperazine with 1-(o-Chlorophenyl)-1-phenyl-2-propyn-1-ol
Authors: Yabuki Tetsuro , Yasui Masanori , Tezuka Hiroshi , Harada Shigeharu , Kasai Nobutami , Tanaka Koichi , Toda Fumio
Published: July 2006

The N,N′-dimethylpiperazine molecule in the title crystals is bound by two chiral acetylenic alcohol molecules through the strong O–H···N hydrogen bonds. The symmetric 1:2 complex of N,N′-dimethylpiperazine with (+)- and (−)-1-(o-chlorophenyl)-1-phenyl-2-propyn-1-ol(CPPOH), which is useful for the optical purification of partially resolved CPPOH, has the denser packing of molecules in the crystal than the asymmetric 1:2 complex of N,N′-dimethylpiperazine with two (−)-CPPOH.
Formation and Spin Density Distribution of the Radical Anion and Radical Trianion of Bis[diphenylpyradino]tetracyanoquinodimethane Studied by ESR
Authors: Hirayama Masatoshi , Seki Akihiko , Yamashita Yoshiro , Suzuki Takanori , Miyashi Tsutomu
Published: July 2006

The radical trianion of title compound as well as its radical anion was formed by electrolytic reduction of its neutral precursor in acetonitrile at room temperature and characterized by their ESR and calculated spin density distributions.
Preparation and Structure of a Mixed Benzenethiolatosulfido Trinuclear Nickel Complex
Authors: Matsumoto Keiji , Nakano Hideyuki , OOI Shun’ichiro
Published: July 2006

X-Ray structure analysis of [Ni3S(SPh)6]2− has revealed that a central μ3-S and three Ni atoms form a trigonal pyramid, a μ-SPh ligand bridges each pair of the three Ni atoms situated at the apexes of a triangle, and each Ni is terminally coordinated by SPh, completing a trinuclear complex. The stereochemistry around Ni is tetrahedrally distorted square planar.
Reaction of Stabilized Bismuthonium Ylides with Aldehydes. A Novel Reaction Mode of the Heaviest Group V Element Ylide
Authors: Ogawa Takuji , Murafuji Toshihiro , Suzuki Hitomi
Published: July 2006

Stabilized bismuthonium ylides, triphenylbismuthonio-4,4-dimethyl-2,6-dioxocyclohexane-1-ide and triphenylbismuthonio-4,4-dimethyl-2,6-dioxo-3,5-dioxan-1-ide, react with aldehydes to afford three types of products; tetraacylcyclopropanes, dihydrofurans, and α,β-unsaturated carbonyl compounds, the relative importance of these depending greatly on the ylides, aldehydes, and reaction conditions employed.
Trapping of Trifluoromethyl Radical with Enolacetate and in situ Generated Enol
Authors: Uneyama Kenji , Ueda Kunimasa
Published: July 2006

Electrochemically generated trifluoromethyl radical can be trapped with enolacetates and enol generated in situ from β-ketoesters and 1,3-diketones, affording trifluoromethylated active methylene compounds.
Crystal and Electronic Structures of a New Two-dimensional Molecular Metal, α-Et2Me2N[Ni(dmit)2]2
Authors: Kato Reizo , Kobayashi Hayao , Kim Hyerjoo , Kobayashi Akiko , Sasaki Yukiyoshi , Mori Takehiko , Inokuchi Hiroo
Published: July 2006

The anion radical salt α-Et2Me2N[Ni(dmit)2]2 retains metallic behavior down to 1.5 K. Planar Ni(dmit)2 units lying side-by-side along the b axis stack along the c axis in such a way that one molecule overlaps with two molecules. Such a “spanning overlap” mode has provided two-dimensional electronic structure.
Significance of Silicate Source for Controlling Pentasil Zeolite Phase Synthesized from Organic-Free System
Authors: Dai Feng-Yuen , Deguchi Kenzo , Suzuki Minoru , Takahashi (late)Hiroshi , Saito Yasukazu
Published: July 2006

High resolution 29Si NMR spectra of silica sols and water glass in addition to a wide survey of hydrothermal zeolite syntheses from them with no aid of organic templates brought forth such a view that pentasil zeolite phases to be formed are contrlled at the aging stage of room temperature in the liquid phase. Pure ZSM-5 crystals were synthesized at high yields, only when a small-sized silica sol(10–20 nm) was used, indicating that appropriate amounts of silicate species(Q2 and Q3) are required to react with aluminate at room temperature in the alkaline solution.
Palladium-Catalyzed Regio- and Stereoselective Aryldesilylation of α-Silylstyrenes with Arenediazonium Salts
Authors: Ikenaga Kazutoshi , Matsumoto Satoshi , Kikukawa Kiyoshi , Matsuda Tsutomu
Published: July 2006

α-Trialkylsilylstyrenes[Ph(R3Si)C=CH2: R=Me(1), Et(2), and Ph (3)] easily reacted with arenediazonium tetrafluoroborates[ArN2+BF4− (4)] to give (E)-PhCH=CHAr under palladium(0) catalysis. The bulky substituents on silicon gave better stereoselectivity.
Ullmann Ether Synthesis in DMI. Preparation of m-Phenoxybenzyl Alcohol
Authors: OI Ryu , Shimakawa Chitoshi , Takenaka Shinji
Published: July 2006

The condensation of m-hydroxybenzyl alcohol with chlorobenzene was examined in several different solvents, and an effective route to m-phenoxybenzyl alcohol has been developed by using 1,3-dimethyl-2-imidazolidinone (DMI) as a solvent.
Improvement of Adsorption Capacity for Copper (II) Ion by N-Nonanoylation of Chitosan
Authors: Kurita Keisuke , Chikaoka Satoyuki , Koyama Yoshiyuki
Published: July 2006

Chitosan was selectively N-nonanoylated, and the influence of the long acyl groups on the adsorption of copper (II) ion was studied. The acylation with nonanoyl chloride was achieved efficiently on a highly swelled chitosan precipitate. The adsorption capacity could be improved markedly by a small extent of acylation.
The Stereoselective Michael Reaction of α,β-Unsaturated Thioesters with Silyl Enol Ethers Promoted by Combined Use of Antimony(V) Chloride and Tin(II) Triflate
Authors: Kobayashi Shu , Tamura Masanori , Mukaiyama Teruaki
Published: July 2006

α, β-Unsaturated thioesters react with silyl enol ethers to afford the corresponding Michael adducts stereoselectively in high yields by the use of a new catalyst, combined use of antimony(V) chloride and tin(II) triflate.
Crystal Structure of Potassium Salt of Synthetic Carboxylic Ionophore
Authors: Kuboniwa Hitoshi , Yamaguchi Kazuo , Nakahama Seiichi , Hori Kayako , Ohashi Yuji
Published: July 2006

Crystal structure of potassium [[2-[2-[2-[2-[2-[2-[2-(2-hydroxyethoxy)phenoxy]ethoxy]phenoxy]ethoxy]phenoxy]ethoxy]phenoxy]methyl]benzoate (2) has been determined. The backbone forms pseudocycle by head-to-tail hydrogen bonding. Conformations about C–C and C–O bonds are gauche and trans respectively, except for two of the C–O bonds which are gauche to make the pseudocyclic backbone bend like seam of a tennis ball. Ten oxygens except for one of the benzoate group coordinate with the potassium ion.
Thermoinitiated Cationic Polymerization of Styrene with a Pyridinium Salt
Authors: Uno Hitomi , Takata Toshikazu , Endo Takeshi
Published: July 2006

N-Benzyl-p-cyanopyridinium hexafluoroantimonate behaved as a thermally latent catalyst to initiate the cationic polymerization of styrene at 120 °C leading to polystyrene possessing a bimodal molecular weight distribution.
Preparation of YBa2Cu3O7−x Films by Chemical Vapor Deposition
Authors: Yamane Hisanori , Kurosawa Hideyuki , Hirai Toshio
Published: July 2006

YBa2Cu3O7−x films were prepared on yttria stabilized zirconia substrates at a deposition temperature of 1073 K under reduced pressures using β-diketonate chelates of Y, Ba, and Cu as source materials for CVD.
Molecular Orbital Considerations for Kinetically-Controlled Cycloaddition Reactions of Cyclohepta[b]furan-2-ones to 2,3-Bis(methoxycarbonyl)-7-oxabicyclo[2.2.1]heptadiene, Enamines, and Alkoxyethenes
Authors: Tian Guan Rong , Sugiyama Shigeru , Mori Akira , Takeshita Hitoshi , Higashi Miwako , Yamaguchi Hiroyuki
Published: July 2006

2,3-Bis(methoxycarbonyl)-7-oxabicyclo[2.2.1]heptadiene gave the [4+2] cycloadducts with 8,8-dicyanoheptafulvene and cycloheptaf[b]-furan-2-ones. This mode is different from the [8+2] cycloadduct formations with the previously studied enamines and alkoxyethenes. The results from MNDO calculations were in accord to the observed modes of the cycloadditions. Thermolysis of the cycloadducts gave the methylidene derivatives of “homobarrelenes”.
Spectroscopic Evidence for the Inter-Chain Charge–Transfer Interaction in Copper-bis(2,5-dimethyl-N,N′-dicyanoquinonediimine), Cu(2,5-DM-DCNQI)2
Authors: Yakushi Kyuya , Ojima Gen , Ugawa Akito , Kuroda Haruo
Published: July 2006

Polarized reflectance spectra of the single crystals of Cu(2,5-DM-DCNQI)2 and Na(2,5-DM-DCNQI)2 were measured at room temperature. The spectrum of Cu(2,5-DM-DCNQI)2 clearly indicated the inter-chain interaction through the coordinate bonds, whereas the spectrum of Na(2,5-DM-DCNQI)2 showed a typical one-dimensional feature along the stacking direction.
Palladium-Catalyzed, Atmospheric Pressure Carbonylation of Allylic Chlorides in Two-Phase Aqueous Sodium Hydroxide–Organic Solvent Media
Authors: Kiji Jitsuo , Okano Tamon , Nishiumi Wataru , Konishi Hisatoshi
Published: July 2006

The palladium-catalyzed, atmospheric pressure carbonylation of allylic chlorides is realized in aqueous NaOH/benzene. Phosphine complexes PdCl2L2 (I) (a, L=Ph2P(m-C6H4SO3Na); b, L=Ph3P), or Na2PdCl4 can be used as the catalyst.
Molecular Structure of Novel 1,2,3-Butatriene Episulfides
Authors: Tokitoh Norihiro , Hayakawa Hiroshi , Goto Midori , Ando Wataru
Published: July 2006

Molecular structures of novel 1,2,3-butatriene 1-episulfide and 2-episulfide derivatives have been determined by X-ray crystallographical analysis, and the structure of the 1-episulfide is in good agreement with the optimized geometries of the parent allene episulfide skeleton obtained from the RHF Closed-Shell SCF calculation.
Selective Detection of Nitrogen Monoxide by the Mixed Oxide of Cr2O3–Nb2O5
Authors: Ishihara Tatsumi , Shiokawa Kazuhiko , Eguchi Koichi , Arai Hiromichi
Published: July 2006

Several single and mixed oxides were used as sensors for detection of CO, CO2, NO, and NO2. The conductivity of (Cr2O3)1-x (Nb2O5)x was greatly changed by a contact with 1-1000 ppm of NO, but was unchanged by that with CO or CO2. The sensitivity to NO was maximum by operating at 573 K using oxide with x=0.1. The influence of CO during detection of NO was negligible at x=0.5.
Short-term administration of an angiotensin-receptor antagonist in patients with impaired fasting glucose improves insulin sensitivity and increases free IGF-I
Authors: Zandbergen Adrienne A M , Lamberts Steven W J , Janssen Joop A M J L , Bootsma Aart H
Published: July 2006

Objective: Blocking the renin–angiotensin system (RAS) may reduce the risk of developing type-2 diabetes, but data are inconclusive and the mechanisms involved are unclear. RAS and RAS inhibition also influence the IGF-I system, which is important in glucose homeostasis. We investigated the effects of the angiotensin-receptor antagonist, losartan, on insulin resistance and IGF-I levels

Design and methods: In this hypothesis-generating study, five individuals with impaired fasting glucose received 100 mg losartan during 8 weeks. Before and after the treatment period, insulin sensitivity was assessed using the homeostasis model assessment of insulin resistance (HOMA), as well as the 2-h continuous infusion of glucose with model assessment (CIGMA). Furthermore, serum levels of free and total IGF-I, IGF-binding protein-3 (IGFBP-3), lipids and HbAlc were measured.

Results: After the treatment period, the HOMA score for insulin resistance had decreased from 5.3 ± 1.1 to 3.7 ± 0.9 (P = 0.004) and the 2-h CIGMA score from 23.4 ± 3.1 to 15.9 ± 2.1 (P = 0.07). The serum levels of free IGF-I had increased from 57 ± 18.8 to 134 ± 31.3 pmol/l (P = 0.04). In terms of percentage, the decrease of HOMA correlated with the increase in free IGF-I levels (Pearson’s correlation coefficient r = −0.8; P = 0.07). A trend in the same direction was observed with 2-h CIGMA. No differences were observed in lipids, total IGF-I, IGFBP-3 or HbAlc.

Conclusions: Losartan raised serum levels of free IGF-I, which might contribute to the improvement of insulin resistance associated with losartan treatment. These observations, if confirmed in broader studies, will help our understanding of the pathogenesis of type-2 diabetes mellitus, as well as the role of angiotensin-receptor antagonists in its prevention.
Noncell- and Cell-Autonomous G-Protein-Signaling Converges With Ca2+/Mitogen-Activated Protein Kinase Signaling to Regulate str-2 Receptor Gene Expression in Caenorhabditis elegans
Authors: Lans Hannes , Jansen Gert
Published: July 2006

In the sensory system of C. elegans, the candidate odorant receptor gene str-2 is strongly expressed in one of the two AWC neurons and weakly in both ASI neurons. Asymmetric AWC expression results from suppression of str-2 expression by a Ca2+/MAPK signaling pathway in one of the AWC neurons early in development. Here we show that the same Ca2+/MAPK pathway promotes str-2 expression in the AWC and ASI neurons together with multiple cell-autonomous and noncell-autonomous G-protein-signaling pathways. In first-stage larvae and adult animals, signals mediated by the Gα subunits ODR-3, GPA-2, GPA-5, and GPA-6 and a Ca2+/MAPK pathway involving the Ca2+ channel subunit UNC-36, the CaMKII UNC-43, and the MAPKK kinase NSY-1 induce strong str-2 expression. Cell-specific rescue experiments suggest that ODR-3 and the Ca2+/MAPK genes function in the AWC neurons, but that GPA-5 and GPA-6 function in the AWA and ADL neurons, respectively. In Dauer larvae, the same network of genes promotes strong str-2 expression in the ASI neurons, but ODR-3 functions in AWB and ASH and GPA-6 in AWB. Our results reveal a complex signaling network, encompassing signals from multiple cells, that controls the level of receptor gene expression at different developmental stages.