bluuebunny/crossref_metadata_2025 huggingface dataset:
Light- and Heat-Induced Geometric Isomerization of Chloro(hydrido)iridium(III) Complex Containing a (2-Phosphinoethyl)silyl Chelate Ligand
Authors: Okazaki Masaaki , Kawano Yasuro , Tobita Hiromi , Inomata Shinji , Ogino Hiroshi
Published: March 2006

Photolysis of chloro(hydrido)(silyl)iridium complex [Ir(Cl)(H){HMesSi(CH2)2PPh2}(PMe3)2] (1) caused the geometric isomerization to 2 which reached to a photostationary state with the ratio of 1 : 2 = 29 :71. Both 1 and 2 take mer configuration, but 1 has a hydrido ligand opposite to one of PMe3’s while 2 has that opposite to the PPh2. On thermolysis, 2 reverted to 1 quantitatively.
Fluoro-functionalized Molecularly Imprinted Polymers Selective for Herbicides
Authors: Matsui Jun , Miyoshi Yoko , Takeuchi Toshifumi
Published: March 2006

Polymers molecularly imprinted against a herbicide prometryn were prepared using (2-trifluoromethyl)acrylic acid (TFMAA) as a new monomer to construct complementary binding sites within the polymers. In chromatographic studies, the polymers with TFMAA exhibited higher affinity and selectivity for the template prometryn than those prepared with a conventional monomer methacrylic acid (MAA).
Multi-Podands. Ag(I) Complexation with Mono- to Quadru-Podands Having Sulfur Donor
Authors: Lee Shim Sung , Park Jung Min , Kim Dae Yeon , Jung Jong Hwa , Cho Moon Hwan
Published: March 2006

A series of mono- to quadru-podand having same arms were synthesized and thermodynamic parameters for the complexation with Ag(I) in methanol have been determined. All of the podands except mono-podand form 1:1 complexes with Ag(I) definitely and the complexation was enthalpy driving. Binding characteristics were also examined by NMR and solvent extraction.
Chiral Recognition in the Electron-Transfer Reaction between Optically Active Schiff Base-Oxovanadium(IV) and -Oxovanadium(V) Complexes
Authors: Nakajima Kiyohiko , Ando Yuki , Inamo Masahiko , Kojima Masaaki
Published: March 2006

The kinetics of the electron-transfer reaction between [VO{3-MeOsal-(RR) or (SS)-chxn}] and [VO{sal-(RR)-chxn}]+ were studied using the stopped-flow method in acetonitrile over the temperature range of 5 – 25 °C. The reactions were enantioselective. The ratio of the rate constant of the electron-transfer between [VO{3-MeOsal-(SS)-chxn}] and [VO{sal-(RR)-chxn}]+ (kSS-RR) and that between [VO{3-MeOsal-(RR)-chxn}] and [VO{sal-(RR)-chxn}]+ (kRR-RR) was 2.0 (kSS-RR / kRR-RR) at 25 °C.
Insertion of Electron-Deficient Olefins into the C–H Bond of 2-Furanyl- and 2-Thienylplatinum Complexes
Authors: Onitsuka Kiyotaka , Urayama Hiroshi , Sonogashira Kenkichi , Ozawa Fumiyuki
Published: March 2006

The treatment of 2-furanylplatinum with maleic anhydride (MA), tetracyanoethylene (TCNE) and 7,7,8,8-tetracyanoquinodimethane (TCNQ) results in insertion of the olefins into the C–H bond of furanyl group at the 5-position. 2-Thienylplatinum complex similarly reacts with TCNE and TCNQ to give the insertion products.
Preparation of Diethyl 3-Hydroxy-1-alkenylphosphonates by the Reaction of Diethyl (Arylsulfinylmethyl)phosphonate with Aldehydes under the Knoevenagel Conditions
Authors: Nokami Junzo , Taniguchi Akito , Honda Masayuki , Fukutake Satoshi
Published: March 2006

The title compounds were prepared by the reaction of diethyl (arylsulfinylmethyl)phosphonate with aldehydes in the presence of piperidine in aceto(or propio)nitrile.
Enantioselective Synthesis of trans-Whisky Lactone by Using Newly Developed Asymmetric Ring Expansion Reaction of Oxetane as a Key Step
Authors: Ito Katsuji , Yoshitake Miwa , Katsuki Tsutomu
Published: March 2006

A mixture of optically active 3-substituted cis- and trans-tetrahydrofuran-2-carboxylates which was prepared in one step from readily available (±)-2-alkynyloxetane, was converted into trans-whisky lactone (2) in a straightforward manner.
Formation of Si, Al Solid Solution in the Sodalite Framework and Its Characterization
Authors: Sato Mitsuo , Uehara Hirofumi , Kojima Eiji , Miyake Michihiro
Published: March 2006

A formation of complete solid solution series of Si, Al in the sodalite framework was tried in a non aqueous solution. Two types of solid solutions could be successfully prepared. The one was in the region of Si/Al ratio from ∞ to 1.4, and the other from 2.0 to 1.0. The former was assigned as type A, while the other type B. Their X-ray powder diffraction, thermoanalysis and 29Si NMR data were characterized.
Adsorption of Amphiphilic Block Copolymer-Catalase Aggregate at Silica-Gel
Authors: Naka Kensuke , Kitano Noriaki , Iwaki Kaoru , Ohki Akira , Maeda Shigeru
Published: March 2006

The amount of adsorbed catalase at silica-gel in aqueous solution at pH 7.0 was significantly increased in a presence of the polymer aggregate which was prepared from an amphiphilic block copolymer (1) consisting of poly[(N-pentanoylimino)ethylene] and poly[(N-acethylimino)ethylene].
Ab initio Study of the C12-C13 Conformation of 11-cis-retinal
Authors: Houjou Hirohiko , Sakurai Minoru , Asakawa Naoki , Inoue Yoshio , Tamura Yusuke , Watanabe Yoichi
Published: March 2006

Ab initio calculation was performed to appreciate 13C NMR chemical shift variations of 11-cis-retinal. The results show that isotropic shift of C12 varies significantly as the C12-C13 single bond rotates. This factor seems to be important to discuss a state of the chromophore in the protein.
Neutral 1,4-Bis(3-thiapentylxanthato)butane as Sensing Material for Samarium(III) Ion
Authors: Ogata Takashi , Chowdhury Didarul A , Kamata Satsuo , Usui Yoshiharu , Ohashi Kousaburo
Published: March 2006

Membrane-coated carbon rod electrodes were constructed by incorporating 1,4-bis(3-thiapentylxanthato)butane as the active ionophore. These electrodes exhibited near Nernstian responses with a slope of 19.7 mV per decade of concentration change, toward samarium(III) ion. The observed detection limit for determination of Sm(III) was 5 × 10−7 M (1M = 1 mol dm−3) in aqueous solutions. The selectivity coefficients of the electrode against a number of diverse ions are discussed.
Preparation and Structure of Dinuclear Vanadium(III) Complex Triply Bridged by Three Different Groups
Authors: Kanamori Kan , Okayasu Takako , Okamoto Ken-ichi
Published: March 2006

A new dinuclear vanadium(III) complex, [V2(bza)(OH)(tphpn)(H2O)2]Cl3, was prepared and its structure was characterized by X-ray crystallography, where bza is benzoate and tphpn is an anion of N, N, N′, N′-tetrakis(2-pyridylmethyl)-2-hydroxy-propane-1,3-diamine.
Isolation and Characterization of 4-Chloro-6,7-dimethoxybenzoxazolin-2-one, A New Auxin-inhibiting Benzoxazolinone from Zea mays
Authors: Kosemura Seiji , Emori Hideyuki , Yamamura Shosuke , Anai Toyoaki , Aizawa Hiroko , Ohtake Nobuyuki , Hasegawa Koji
Published: March 2006

A new auxin-inhibiting substance was isolated from light-grown maize shoots. The structural determination was performed by spectroscopic methods and synthesis of 4-chloro-6,7-dimethoxybenzoxazolin-2-one.
Novel Synthesis of Disubstituted Alkyne Using Molybdenum Catalyzed Cross-Alkyne Metathesis
Authors: Kaneta Naotake , Hikichi Ken , Asaka Shin-ichi , Uemura Motokazu , Mori Miwako
Published: March 2006

A novel disubstituted alkyne synthesis was developed using molybdenum catalyzed cross-alkyne metathesis by Mortreux’s catalyst [Mo(CO)6-p-ClC6H4OH]. The reaction was carried out using Mo(CO)6 (5 mol% for total amounts of alkynes) and p-ClC6H4OH (1 equiv.) in the presence of an excess amount of another alkyne (3∼11 equiv.) in refluxing toluene.
Selective Allylations of Selenothioic Acid S-Alkyl Esters with Allylic Bromides
Authors: Murai Toshiaki , Takada Hiroya , Kanda Takahiro , Kato Shinzi
Published: March 2006

Allylations of selenothioic acid S-alkyl esters with allylic bromides in the presence of Et3N in THF took place selectively at the α-position of selenocarbonyl group to give allylated products with high regio- and stereo-selectivity.
A Method of Evaluating the Rate Constant of the Thermal Isomerization of 6-SO3−-spiropyran by Using β-Cyclodextrin
Authors: Sueishi Yoshimi , Nishimura Tomonori , Miyakawa Tamami
Published: March 2006

The thermal isomerizations of 1′,3′,3′-trimethyl-spiro[2H-1-benzopyran-2,2′-indoline]-6-sulfonic acid between its spiro (SP) and merocyanine (MC) forms were followed spectrophotometrically by using β-cyclodextrin as the control of the isomerization reaction. The rate constants of the thermal isomerizations were estimated to be 2.27 × 10−3 s−1 for MC → SP and 3.03 × 10−3 s−1 for SP → MC.
Regioselective C-Functionalization of 2,3-Dicyanopyrazine Derivatives via Photoinduced Electron Transfer
Authors: Mizuno Kazuhiko , Konishi Gen-ichi , Nishiyama Toshinori , Inoue Hiroo
Published: March 2006

Irradiation of an acetonitrile solution containing 2,3-dicyano-5,6-diphenylpyrazine with allylic silanes, benzylsilane, and ketene silyl acetal gave the mono-substituted products in excellent yields. This reaction is useful for the functionalization of pyrazine ring.
Electrooxidative Polymerization of Tetraphenylporphinatoruthenium(II) Complexes with Diaza Compounds as Axial Ligands
Authors: Saito Miki , Endo Akira , Shimizu Kunio , Satô Gen P
Published: March 2006

A “shish-kebab” type polymer film is formed by the two-electron oxidation of [Ru(tpp)L2] (H2tpp = tetraphenylporphine; L = trans-1,2-bis(4-pyridyl)ethylene, 4,4′-bipyridine, or 1,2-bis(4-pyridyl)acetylene) in 0.1 mol dm−3 (n-C4H9)4N(ClO4)-CH2Cl2. The polymers were characterized by cyclic voltammetry and UV-vis/IR spectrophotometry.
The Effect of Trace Iron in the Magnetic Property of the Fine Particle Prepared by ArF Laser-Induced Ablative Photodecomposition of Solid Perylenetetracarboxylic Dianhydride
Authors: Ouchi Akihiko , Saito Kimitsugu , Koga Yoshinori
Published: March 2006

Organic fine particles were prepared by ArF laser-induced ablative photodecomposition of 3,4,9,10-perylenetetracarboxylic dianhydride containing trace amount of iron (3.5 ∼ 2200 ppm). Sudden change in the magnetic property of the particles, from diamagnetic to paramagnetic, was observed between the iron content of 2000 and 2100 ppm.
Asymmetric Induction in the Palladium-catalyzed Nucleophilic Substitution Reactions of Chiral β-Sulfinylallylic Systems
Authors: Hiroi Kunio , Onuma Hiroshi , Arinaga Yoshihisa
Published: March 2006

The first example of the palladium-catalyzed asymmetric nucleophilic substitutions of chiral β-sulfinylallylic systems is described. The degree of the asymmetric induction was dependent on the reaction conditions, especially a phosphine ligand used. The plausible mechanism of the asymmetric induction is proposed on the basis of the stereochemical results obtained.
Stoloniolide I and II, New Marine Lactonic Steroids with an Unprecedented 1,10-Secoergostane Skeleton, Isolated from the Okinawan Soft Coral, Clavularia viridis
Authors: Iguchi Kazuo , Iwashima Makoto , Watanabe Kinzo
Published: March 2006

Two novel lactonic steroids, stoloniolide I and II, were isolated from the Okinawan soft coral, Clavularia viridis Quoy and Gaimard. Their structures were determined by spectroscopic analysis. They each possessed a unique 1,10-secoergostane skeleton unprecedented in the field steroids.
Photoinduced Hydride Reduction of 10-Methylacridinium Ion by Alkylbenzenes in the Presence of Perchloric Acid
Authors: Fujita Morifumi , Ishida Akito , Majima Tetsuro , Fukuzumi Shunichi , Takamuku Setsuo
Published: March 2006

Photoinduced hydride reduction of 10-methylacridinium ion (AcrH+) by alkylbenzene occurs to yield 10-methyl-9,10-dihydroacridine in the presence of perchloric acid, while photoaddition occurs to yield 9-alkyl-10-methyl-9,10-dihydroacridine in the absence of perchloric acid. The hydride reduction of AcrH+ in the presence of perchloric acid proceeds via protonation of acridinyl radical produced by photoinduced electron transfer from alkylbenzene.
A New and Efficient Approach for the Synthesis of Peptides Containing Aspartylglycyl Sequences
Authors: Zhang Hong , Wang Yali , Voelter Wolfgang
Published: March 2006

H-Asp(OBut)-Gly, coupled to the 2-chlorotrityl resin, does not undergo aspartimide cyclization upon further solid phase peptide elongation via the Fmoc strategy. Prolonged peptide fragments, side chain and N-terminally Nps-protected, are suitable intermediates for fragment condensations of long-chain Asp-Gly-containing peptides.
Preparation of 1,4-Dicyanobenzene Derivatives and the Substituent Effect of the Sensitizers on Photoinduced Electron-Transfer Reactions
Authors: Osoda Kazuhiko , Pannecoucke Xavier , Narasaka Koichi
Published: March 2006

Substituted 1,4-dicyanobenzenes are prepared as electron-accepting photosensitizers. The efficiency of some photosensitized reactions is influenced remarkably by the substituent(s) of 1,4-dicyanobenzene. By using mono or dimethylated dicyanobenzene, the reactions proceed more rapidly as compared with that by using 1,4-dicyanobenzene itself.
Palladium-Catalyzed Allylic Amination of Allylic Alcohols with Tin(II) Chloride and Triethylamine
Authors: Masuyama Yoshiro , Kagawa Masaaki , Kurusu Yasuhiko
Published: March 2006

Allylic alcohols caused allylic amination with primary or secondary amines in the presence of a catalytic amount of Pd(PPh3)4 and a stoichiometric amount of tin(II) chloride in THF at 50 °C to produce the corresponding allylic amines regioselectively.
Doubly Hydrogen-Bonded Liquid-Crystalline Complexes Obtained by Supramolecular Self-Assembly of 2,6-Diacylaminopyridines and 4-Alkoxybenzoic Acids
Authors: Kato Takashi , Kubota Yasuo , Nakano Masahisa , Uryu Toshiyuki
Published: March 2006

Doubly hydrogen-bonded complexes obtained by 1:1 supramolecular self-assembly of 2,6-diacylaminopyridines and 4-alkoxybenzoic acids exhibit liquid-crystalline behavior.
2,2,2-Trifluoroethyl Chloroformate as a Rapid Derivatizing Reagent of Amino Acids for Fast Enantiomer Separation by Gas Chromatography
Authors: Abe Iwao , Fujimoto Noriteru , Nakahara Taketoshi
Published: March 2006

Amino acids were derivatized rapidly into N(O)-2,2,2-trifluoroethoxycarbonyl 2′,2′,2′-trifluoroethyl esters for enantiomer separation by chiral phase capillary gas chromatography. All the derivatives showed considerable reduction in retention times compared with N(O)-ethoxycarbonyl ethyl ester derivatives with almost complete separation of their enantiomers.
Reactions of C60 with α-Silylamine Derivatives: Two Types of [3+2] Addition of Azomethine Ylides to C60
Authors: Iyoda Masahiko , Sultana Fatema , Komatsu Mitsuo
Published: March 2006

Thermal [3+2] cycloaddition of C60 with α-silylamine derivatives proceeds smoothly under neutral conditions to afford fullerene-fused pyrrolidines and 1-pyrrolines in moderate to good yields. The new methods are effective for constructing fullerene derivatives containing bulky aryl-substituents.
Unusual Intermolecular Short Contacts of C···C = 2.3 Å in Crystal Structure of Copper Complex of Schiff Base of Vitamin B6 Phosphate Ester; Does It Reveal an Intermediate Structure to σ-Covalent Bond Formation ?
Authors: Ishida Toshimasa , In Yasuko , Nagata Hiroomi , Doi Mitsunobu , Wakahara Akio
Published: March 2006

The crystal structure of copper complex of Schiff base of pyridoxal-5-phosphate and pyridoxamine-5-phosphate showed the strikingly short intermolecular C···C contact of ∼ 2.3 Å. Since this value corresponds just to a transition state for cycloaddition reaction estimated by ab initio calculation, the present result may be the first structural presentation of an intermediate structure from the noncovalent π–π interaction to the σ-covalent bond formation.
Polysilane Synthesis by Catalytic Disproportionation of Alkoxydisilanes with Organolithium Reagents
Authors: Kabeta Keiji , Wakamatsu Shigeru , Imai Takafumi
Published: March 2006

Network polysilanes with various substituents have been prepared by a disproportionation reaction of 1,1,2,2-tetraethoxy-1,2-dimethyldisilane with a small amount of organolithium reagents. Aromatic dilithio compounds lead to incorporation of aromatic bridges into the network polysilanes, which show relatively higher electroconductivity by iodine doping. It seems that lithium ethoxide catalyzes the polymerization.
Transport Performance of Nucleosides through Nucleic Acid Bases Conjugated Hyaluronan
Authors: Chirachanchai Suwabun , Wada Takehiko , Inaki Yoshiaki , Takemoto Kiichi
Published: March 2006

The transport performance of nucleosides through the membranes of hyaluronic acid and deacetylated hyaluronan conjugated with nucleic acid base derivatives has been studied under varied temperature. Partition coefficient values of the permeants and permeabilities of the membranes showed the selectivity of nucleosides due to the effect of specific interaction between the permeants and nucleic acid base moiety in the membrane.
Temperature Dependent Fluorescence of ‘Tunable Fluorophore-Fissile Bond’ Systems Based on 1-Phenyl, 3-Aryl Δ2-Pyrazolines as a Means of Quantitating Photofission Processes
Authors: Silva A Prasanna de , Gunaratne H Q Nimal , Jayasekera K Ranjith , O’Callaghan Sean , Sandanayake K R A Samankumara
Published: March 2006

The activation energy for the C(5)-N(1) bond homolysis in the lowest excited singlet state of the 1-Phenyl, 3-Aryl, 5-(2′Phenylethenyl) Δ2-pyrazolines as deduced from the temperature dependence of the fluorescence quantum yield (ΦF) can be combined with the corresponding singlet energy to give a constant value of 75.5 kcal mol−1 as the total photofission energy. The corresponding value for 1,3-Diphenyl, 5-(2′-Iodo phenyl) Δ2-pyrazoline significantly exceeds the bond dissociation energy (BDE) of the aryl carbon-iodine linkage.
Oxidation of Benzaldehydes Catalyzed by Methyltrioxorhenium with Hydrogen Peroxide
Authors: Yamazaki Shigekazu
Published: March 2006

Methyltrioxorhenium-catalyzed oxidation of benzaldehydes with hydrogen peroxide gives corresponding phenols in good yield. Benzaldehydes substituted with methoxy or hydroxyl groups at 2- and/or 4-position are good substrates for this reaction.
Synthesis, Structure, and Magnetic Properties of Triply Carboxylato-Bridged Dimanganese(II) Complexes
Authors: Matsushima Hideaki , Ishiwa Eiko , Koikawa Masayuki , Nakashima Michio , Tokii Tadashi
Published: March 2006

Two dinuclear manganese(II) complexes, [Mn2(Ph2MeCCOO)3(bpy)2](PF6) (1) and [Mn2(C6H5COO)3(CH3OH)(bpy)2](NO3) (2), have been prepared. X-Ray structural analyses have revealed that complexes 1 and 2 have a different bridging mode in triple carboxylato-bridges between two manganese(II) ions each other.
Restriction-Enzyme-Nondependent Recombination and Rearrangement of DNA (RRR)
Authors: Nishigaki Koichi , Kinoshita Yasunori , Kyono Hiroshi
Published: March 2006

A new technology for recombinating DNAs was developed. This method utilizes ribonucleotide–containing DNAs (RCDs) as primers to obtain PCR products and subsequently generate sticky ends by cleaving at the ribonucleotide site. This method also enables us to generate combinatorial diversities of primers, which are useful for exon-shuffling.
Surface-Assisted Photoinduced Reduction of p-Nitrothiophenol Self-Assembled Monolayer Adsorbed on a Smooth Silver Electrode
Authors: Matsuda Naoki , Sawaguchi Takahiro , Osawa Masatoshi , Uchida Isamu
Published: March 2006

It was observed that surface-enhanced Raman scattering (SERS) spectra of p-nitrothiophenol (PNTP) self-assembled monolayer adsorbed on a smooth silver electrode changed by laser light irradiation. The SERS spectra were identical with those of p-aminothiophenol (PATP). This reaction proceeded even at the electrode potential where PNTP was electrochemically stable under dark. It was found that photoinduced reduction of PNTP occurred on a smooth silver electrode surface.
The Raman Spectra of trans-Stilbene Radical Cations in Boric Acid Matrices
Authors: Kuriyama Yasunao , Oishi Shigero
Published: March 2006

Photoionization of trans-stilbene to radical cation in boric acid matrices was performed at room temperature. We report the Raman spectra of monomer and dimer radical cation of trans-stilbene.
Silicalite Membrane for Separation of Acetic Acid / Water Mixture
Authors: Sano Tsuneji , Ejiri Shigeyuki , Hasegawa Masaru , Kawakami Yusuke , Enomoto Naoki , Tamai Yoshinori , Yanagishita Hiroshi
Published: March 2006

The polycrystalline silicalite membrane was prepared on a porous sintered stainless steel support and its pervaporation performance was investigated using an acetic acid / water mixture as a feed. The silicalite membrane selectively permeates acetic acid in the concentration of the feed acetic acid in the region of 5 to 40 vol%.
The Boron Trifluoride Catalyzed Aldol Reaction of Methyl 2-(Trimethylsiloxy)acrylate with Aldehydes in the Presence of Alcohols
Authors: Watanabe Mikio , Kobayashi Hideki , Yoneda Yukihiro
Published: March 2006

The boron trifluoride etherate catalyzed aldol reaction of methyl 2-(trimethylsiloxy)acrylate with aldehydes proceeded smoothly in the presence of primary, secondary and tertiary alcohol to give corresponding γ-alkoxy-α-ketoesters.
Solvent Effect on Enantioselective Hydrogenation of (E)-α-Phenylcinnamic Acid with Cinchonidine-Modified Palladium Catalysts
Authors: Nitta Yuriko , Kobiro Kazuya
Published: March 2006

The use of a solvent with larger dielectric constant results in higher enantioselectivity in the hydrogenation of (E)-α-phenylcinnamic acid with a cinchonidine-modified Pd catalyst. The reaction in N,N-dimethylformamide containing 10vol% of water with a 5wt% Pd/TiO2 catalyst leads to an optical yield of 53% of S-(+)-2,3-diphenylpropionic acid.
Chlorotrimethylsilane-Acetonitrile System as a New Promoter for Carbonyl Allylation by Diallyldibutyltin
Authors: Yasuda Makoto , Fujibayashi Tatsuya , Shibata Ikuya , Baba Akio , Matsuda Haruo , Sonoda Noboru
Published: March 2006

Chlorotrimethylsilane combined with acetonitrile has characteristically promoted allylation of carbonyl compounds by diallyldibutyltin to produce a variety of homoallyl silyl ether in good yields, while the addition of HMPA or LiCl disturbed the allylation.
Fulgenolides. Thermally Irreversible Photochromic Lactones with Large Quantum Yields of Photoreactions
Authors: Yokoyama Yasushi , Serizawa Tohru , Suzuki Satoshi , Yokoyama Yayoi , Kurita Yukio
Published: March 2006

Three new photochromic lactones closely related to an indolylfulgide were synthesized. While the lactones with the carbonyl group adjacent to the isopropylidene group have large quantum yields of photoreactions, the isomer with the carbonyl adjacent to the indolylethylidene group showed poor photochromic properties. The absorption maxima of the colored forms of the lactones are shorter than that of the indolylfulgide.
Isolation of an Endogenous Elicitor Induced by Hydrogen Peroxide from Potato
Authors: Monden Tsutomu , Toida Tetsuya , Nakamura Hideshi , Sato Norio , Murai Akio
Published: March 2006

On treatment with hydrogen peroxide, potato tubers released an endogenous elicitor for phytoalexin production. The homogenous active substance, purified by gel filtration and anion exchange column chromatographies, is an acidic polysaccharide with MW 9,200. This constitutes the first isolation of a self-induced endogenous elicitor.
An Asymmetric Synthesis of Fully Functionalized B Ring System of Taxol
Authors: Shiina Isamu , Uoto Kouichi , Mori Nobuaki , Kosugi Tomomi , Mukaiyama Teruaki
Published: March 2006

Optically active 7-t-butyldimethylsiloxy-4,8-dibenzyloxy-6,6-dimethyl-5-p-methoxybenzyloxy-2-cycloocten-1-one (1) was synthesized from 3,7-dibenzyloxy-4,8-di-t-butyldimethylsiloxy-5,5-dimethyl-6-p-methoxybenzyloxy-2-octanone (2) by way of intramolecular Reformatsky-type reaction using SmI2.
Crystalline-State trans-cis Photoisomerization of (trans-2-Butenyl)-bis(dimethylglyoximato)(pyridine)cobalt(III)
Authors: Yamada Taro , Uekusa Hidehiro , Ohashi Yuji
Published: March 2006

The crystal of (trans-2-butenyl)bis(dimethylglyoximato)(pyridine)cobalt(III), 1, gradually changed its unit cell dimensions on exposure to a high flux xenon lamp. After about 2 hours exposure the change became significantly small. The lengths of a and c axes in the orthorhombic unit cell increased and decreased by 0.25 and 0.39 Å, respectively. The crystal structures before and after the irradiation clearly indicated that only the trans-2-butenyl group was transformed to the cis-isomer, the other part of the molecule being unaltered.
An Upper Limit for the Probability of Nuclear Excitation by Electron Transition in 235U
Authors: Shinohara Atsushi , Saito Tadashi , Taniguchi Kazuo , Otozai Kiyoteru , Ikeda Shigero , Baba Hiroshi
Published: March 2006

We have attempted to observe nuclear excitation by electron transition (NEET) in 235U with Mo K X-ray irradiation and off-line radioactivity measurement. Nuclear excitation of the 13-keV level was measured through the isomer radioactivity. An upper limit for the NEET probability was obtained as P < 9 × 10−10.
A Preparation of β-Oxoester Enolate Equivalents from SmI2 and α-Bromoalkanoates
Authors: Utimoto Kiitiro , Matsui Toshiki , Takai Tsutomu , Matsubara Seijiro
Published: March 2006

A treatment of ethyl bromoacetate with two molar equivalent of samarium diiodide at −50 °C for 15 min in THF produces a β-oxoester enolate equivalent; the reagent reacts with ketones or aldehydes to give δ-hydroxy-β-oxoesters in excellent yields.
Fluorocyclization of Unsaturated Aldehydes to Five- or Six-membered Cyclic Fluoroalcohols
Authors: Hayashi Eiji , Hara Shoji , Shirato Hiroyasu , Hatakeyama Tsuyoshi , Fukuhara Tsuyoshi , Yoneda Norihiko
Published: March 2006

In the presence of HF-Et3N complexes, the stereoselective cyclization of 5- and 6-alkenals takes place to give five- and six-membered cyclic fluoroalcohols, respectively.
Vertically Linked Ruthenium(II) Porphyrin Oligomers
Authors: Kimura Akira , Funatsu Kenji , Imamura Taira , Kido Hiroaki , Sasaki Yoichi
Published: March 2006

A novel porphyrin trimer linked vertically, Ru(OEP)(H2PyP3P)2  1, was synthesized and characterized. The trimer showed intriguing MLCT bands. The preparation of a series of three porphyrin oligomers, Ru(OEP)(CO)(H2PyP3P) 2, Ru(OEP)(CO)(ZnPyP3P) 3 , and [Ru(OEP)(CO)]2(trans-H2Py2P2P) 4 were also reported.
Morphology Control of Lithium Deposited in Nonaqueous Media
Authors: Kanamura Kiyoshi , Shiraishi Soshi , Takehara Zen-ichiro
Published: March 2006

An artificial control of the morphology of lithium deposited in nonaqueous media was successfully accomplished by using the surface modification of the as-received lithium metal foil with HF treatment, to suppress the dendrite formation of lithium during the electrochemical deposition.
Selective Isomerization of cis-Stilbene by Non-Resonant Two-Photon Excitation
Authors: Miyazawa Takashi , Koshihara Shin-ya , Segawa Yusaburo , Kira Mitsuo
Published: March 2006

Non-resonant two-photon excitation induced dramatical change in the photoreaction pathways of stilbenes. Typically, irradiation of cis-stilbene with 532 nm laser pulses caused only isomerization to trans-stilbene in hexane at room temperature; the cyclization to dihydrophenanthrene was completely suppressed.
Preparation of Microparticle Palladium Incorporating Poly[N-(5-hydroxypentyl) pyrrole] Film-Coated Electrode
Authors: Takano Nobuhiro , Nakabayashi Masahito , Takeno Noboru
Published: March 2006

The preparation of the palladium microparticles incorporated poly [N-(5-hydroxypentyl) pyrrole] film-coated electrode is described. This electrode exhibited catalytic activity with regard to the hydrogenation of acetylene compound.
Artificial Siderophores as a Model for Ferrichrome. Control of the Δ- or Λ-Configuration of Iron(III) Complexes of Tripodal Hydroxamates by Linking to the C- or N-Terminus of the Same l-Alanyl-l-alanyl-β-(N-hydroxy)alanine Unit
Authors: Akiyama Masayasu , Hara Yukihiro , Gunji Hiroyuki
Published: March 2006

New l-alanyl-l-alanyl-β-(N-hydroxy)alanine-based tripodal hydroxamic acids have been prepared. They form stable chiral complexes with iron(III). The chirality of these complexes can be controlled by a tripodal molecule that links to the C-terminus or N-terminus of the same N-hydroxy peptide unit to give the Λ-cis or Δ-cis configuration about the metal ion, respectively.
Synthesis of the A- and B-Ring System of Hemibrevetoxin-B
Authors: Feng Fei , Murai Akio
Published: March 2006

The A- and B-ring system of hemibrevetoxin-B, which has been isolated from the red tide organism, Gymnodinium breve, has been synthesized in an optically pure form starting from δ-valerolactone.
Stereoselective Addition Reaction of Organolithium Reagents to Chiral Imines Derived from erythro-2-Amino-1,2-diphenylethanol
Authors: Hashimoto Yukihiko , Takaoki Kazuo , Sudo Atsushi , Ogasawara Tsuneo , Saigo Kazuhiko
Published: March 2006

The chiral imines prepared from an artificial chiral auxiliary, erythro-2-amino-1,2-diphenylethanol, and various aldehydes, reacted with organolithium reagents to give the corresponding chiral amines with excellent diastereofacial selectivity.
Reactions of 1-Substituted-polyfluoro-1-propenyl p-Toluenesulfonates with Bifunctional Nitrogen Nucleophiles. A New Expedient Access to Monofluorinated Nitrogen Heterocycles
Authors: Funabiki Kazumasa , Ohtsuki Tetsuya , Ishihara Takashi , Yamanaka Hiroki
Published: March 2006

1-Substituted-2,3,3-trifluoro-1-propenyl p-toluenesulfonates, readily available by the alkylation or arylation of 2,3,3-trifluoro-1-tosyloxy-1-propenyllithium or -zinc reagent, reacted smoothly with amidine or hydrazine derivatives at 70 °C for 1 h to give the corresponding 5-fluoropyrimidine or 4-fluoropyrazole compounds, respectively, in moderate to excellent yields.
Palladium-Catalyzed Acetic Acid Synthesis from Methane and Carbon Monoxide or Dioxide
Authors: Kurioka Masanobu , Nakata Kazuyuki , Jintoku Tetsuro , Taniguchi Yuki , Takaki Ken , Fujiwara Yuzo
Published: March 2006

The Pd(OAc)2/Cu(OAc)2/O2/CF3COOH system has been found to catalyze the direct conversion of methane to acetic acid in the presence of CO. The reaction of methane with CO2 also gave acetic acid in high yields.
Tetracyanoethylene-induced Chlorinative Cleavage of Permethylated Oligogermanes with Polyhalomethanes
Authors: Mochida Kunio , Hata Rieko , Hodota Chikako , Fukuzumi Shunichi , Kako Masahiro , Nakadaira Yasuhiro
Published: March 2006

In the presence of tetracyanoethylene (TCNE), Ge-Ge bonds of oligogermanes (Me(Me2Ge)nMe, n = 2-5) were cleaved with CCl4 to yield the corresponding chlorogermanes. A mechanism involving an oligogermane radical cation is proposed for the Ge-Ge cleavage.
Transesterification Catalyzed by Lanthanoid Tri-2-propoxides
Authors: Okano Tamon , Miyamoto Keiichi , Kiji Jitsuo
Published: March 2006

The transesterification of esters with alcohols was efficiently catalyzed by Ln(OPri)3. The catalytic activity of Ln(OPri)3 decreased in the following order; La > Nd > Gd > Yb, and was much higher than those of Al(OPri)3 and Ti(OPri)4.
Facile Procedure for Acetalization Using Diols, Alkoxysilane and a Catalytic Amount of Trimethylsilyl Trifluoromethanesulfonate
Authors: Kurihara Masaaki , Miyata Naoki
Published: March 2006

In the presence of sec- or tert-alkoxysilane and a catalytic amount of trimethylsilyl trifluoromethanesulfonate (TMSOTf), carbonyl compounds react with various diols to give acetals in high yields.
A Three-Dimensional Warp-and-Woof Structure Interwoven by a Couple of Two-Dimensional Network Layers in the Crystal Structure of [trans-Cd(NH3)2{Ag(CN)2}2]n
Authors: Soma Takayoshi , Iwamoto Toshitake
Published: March 2006

Two sets of the two-dimensional [Cd-(NC-Ag-CN-Cd1⁄4)4]n network layers arrayed vertically to each other interpenetrate through every mesh without any direct chemical bonds to build up the three-dimensionally interwoven supramolecular structure of the title complex.
A New Base-Labile Anchoring Group for Polymer-Supported Oligosaccharide Synthesis
Authors: Wang Yali , Zhang Hong , Voelter Wolfgang
Published: March 2006

A new base-labile 9-hydroxymethylfluorene-2-succinic acid-based anchoring group, coupled to amino-ethylated polyethylene glycol, opens a new approach for polymer-supported syntheses of oligosaccharides using phenyl 1-thioglycopyranoside sulfoxides as highly efficient glycosyl donors.
Electrochemical Acylation of Some Cyclic Olefins by Using Aluminium Anode
Authors: Vukicevic Rastko , Konstantinovic Stanimir , Joksovic Ljubinka , Ponticelli Gustavo , Mihailovic Mihailo Lj
Published: March 2006

The electrochemical acylation of cyclohexene, cycloheptene and their 1-methyl derivatives produces alkyl-cycloalkenyl ketones in good yields. The unsubstituted cycloalkenes give α,β-unsaturated ketones, whereas the 1-substituted derivatives yield mixtures of α,β- and β,γ-unsaturated ketones in which the latter products are predominant.
Total Internal Reflection Fluorescence Measurements of Ion-Association Adsorption of Water-Soluble Porphyrins at Liquid/Liquid Interface
Authors: Watarai Hitoshi , Saitoh Yoriko
Published: March 2006

Ion-association adsorption of water-soluble, surface-inactive anionic and cationic porphyrins with the oppositely charged surfactants was observed at toluene/water interface by means of a total internal reflection fluorometry. Water-soluble zinc(II)-porphyrin was also adsorved at the liquid/liquid interface with a hydrophobic zinc(II)-1,10-phenanthroline complex ion.
Hydrazinium Salts as Novel Thermally Latent Brönsted Acid-Inducing Initiators
Authors: Lee Sang-Bong , Park Young-Suk , Lee Kyu-Wan , Endo Takeshi
Published: March 2006

1,2-Substituted-1,1-dimethylhydrazinium hexafluoroantimonates and their derivatives, R2(Me)2N+NHC(O)R1 SbF6−(2) served as thermally latent cationic initiators in the bulk polymerization of glycidyl phenyl ether. Their initiation temperatures were controlled at 40-140 °C by chemical modification on R1 and R2 of 2. Active species of 2 were suggested to be proton.
A New Synthesis of the Naturally Occurring Free Radical Scavenger Carazostatin
Authors: Shin Kogyoku , Ogasawara Kunio
Published: March 2006

A new synthesis of the naturally occurring free radical scavenger carazostatin has been developed by employing the two aromatic annulation reactions as key steps.
Cleavage of Tin-Carbon Bonds of Organosilylstannane and Organodistannane in Photo-Induced Electron Transfer Reactions and Mass Spectrometry
Authors: Kyushin Soichiro , Otani Shinju , Nakadaira Yasuhiro , Ohashi Mamoru
Published: March 2006

Photoalkylation of tetracyanobenzene and benzil with (n-Bu)3SnSiMe3 or (n-Bu)3SnSn(n-Bu)3 proceeds via electron transfer. In these reactions, the Sn–C bond of (n-Bu)3SnSiMe3 and (n-Bu)3SnSn(n-Bu)3 is cleaved in preference to the Sn–Si and Sn–Sn bonds. Similar cleavage of the Sn–C bond is also observed in mass spectra of these group 14 organometallic compounds.
Dynamics of Polysilane Chain in Dilute Solution as Studied by Spin Labeling
Authors: Sanji Takanobu , Sakamoto Kenkichi , Sakurai Hideki
Published: March 2006

The rotational relaxation times and the rotational energy barriers of spin-labeled poly(phenylmethyl)silane were estimated in four different dilute solvents by the line shape analysis of the ESR signals.
Polysilane Dendrimer. Synthesis and Characterization of [2,2-(Me3Si)2Si3Me5]3SiMe
Authors: Suzuki Hiroshi , Kimata Yoshinori , Satoh Shin , Kuriyama Akira
Published: March 2006

The entitled compound was synthesized by using a step-growth polymerization technique and its molecular structure was determined by X-ray crystallography. This dendrimer showed a distinct UV absorption maximum at 264 nm and exhibited two very feeble fluorescence maxima at 320 nm and 400 nm.
Photochemical Synthesis of Bicyclo[4.1.0]hept-2-enes
Authors: Katayama Sadamu , Yamauchi Masashige
Published: March 2006

Bicyclo[4.1.0]hept-2-enes (norcarenes) were obtained in good yield by photolysis of 3-methylthiomethyl or 3-(2-ethoxycarbonyl)vinylbicyclo[2.2.2]oct-5-en-2-ones in benzene upon high pressure Hg lamp irradiation.
Long-Range Triplet-Triplet Energy Transfer in Supramolecular Species in Fluid Aqueous Solutions
Authors: Nakamura Asao , Imai Takashi , Okutsu Satoshi , Oda Yuji , Ueno Akihiko , Toda Fujio
Published: March 2006

Excitation energy of a metal-to-ligand charge-transferred triplet state of a rhenium complex was transferred over a distance of 10 Å to 2-anthracenecarboxylate trapped in the hydrophobic cavity of the cyclodextrin unit which was linked covalently to one of the ligands of the complex.
First X-Ray Structural Determination of Fullerene [2+2] Cycloadduct
Authors: Ishida Takayuki , Shinozuka Koji , Nogami Takashi , Sasaki Shigeru , Iyoda Masahiko
Published: March 2006

X-Ray crystallographic analysis of a 1:1 adduct of C60 and 4,5-dimethoxybenzyne exhibited a benzocyclobutene structure given by [2+2] cycloaddition reaction at a 6,6-ring junction. A fullerene C(sp3)-C(sp3) bond length is 1.645(8) Å. Relatively short intermolecular C···C, C···O, and C···S distances were found, where sulfur atoms belong to CS2 molecules enclosed.
Electrochemical Os-Catalyzed Asymmetric Dihydroxylation of Olefins with Sharpless’ Ligand
Authors: Torii Sigeru , Liu Ping , Tanaka Hideo
Published: March 2006

Asymmetric dihydroxylation of olefins using Sharpless’ ligand in the presence of potassium osmate [K2OsO2(OH)4] has been attained by recycling use of a catalytic amount of potassium ferricyanide [K3Fe(CN)6] in electrolysis media. The prominent advantage of the electrooxidation method is that minimum use of reoxidizing agent as well as K2OsO2(OH)4 may cause to improve enantioselectivities in comparison with the case of stoichiometric oxidant systems.
Asymmetric Oxidation of Sulfides with Molecular Oxygen Catalyzed by β-Oxo Aldiminato Manganese(III) Complexes
Authors: Imagawa Kiyomi , Nagata Takushi , Yamada Tohru , Mukaiyama Teruaki
Published: March 2006

Enantioselective aerobic oxidation of sulfides with combined use of molecular oxygen and pivalaldehyde afforded the optically active sulfoxides using β-oxo aldiminato manganese(III) complex catalysts. For example, 2-chlorophenyl methyl sulfide afforded optically active sulfoxide in 72% enantiomeric excess.
Synthesis of a New Chiral Auxiliary, (1R,2R,3R,6R)-3,6-Dimethylcyclohexane-1,2-diamine
Authors: Kuroki Takashi , Katsuki Tsutomu
Published: March 2006

(1R,2R,3R,6R)-3,6-Dimethylcyclohexane-1,2-diamine which was expected to serve as an effective chiral auxiliary, was synthesized from (R)-(+)-3-methylcyclohexanone enantio-specifically in a straightforward manner.
Synthesis of Mn-Salen Catalyst Bearing (1R,2R,3R,6R)-3,6-Dimethylcyclohexane-1,2-diamine as an Ethylenediamine Part and Its Application to Asymmetric Epoxidation
Authors: Kuroki Takashi , Hamada Tetsuya , Katsuki Tsutomu
Published: March 2006

The new Mn-salen catalysts bearing (1R,2R,3R,6R)-3,6-dimethylcyclohexane-1,2-diamine as an ethylenediamine part was found to show higher asymmetric induction in the epoxidation of conjugated cis-olefins than the Mn-salen catalyst bearing optically active cyclohexanediamine as an ethylenediamine part. This result supports our proposal that olefins approach metal-oxo bond along nitrogen-manganese bond axis in salen-catalyzed epoxidation.
Zn Mediated Chemoselective Allylation of Keto Esters with Allylic Halides in Aqueous Medium
Authors: Ahonen Matthias , Sjöholm Rainer
Published: March 2006

The Zn mediated reactions of allyl, crotyl and cinnamyl halides with β- and γ-keto esters in THF–NH4Cl(aq) give — by completely selective keto allylation and with good yields — β- and γ-hydroxy esters, respectively. The γ-hydroxy esters were easily and quantitatively converted to γ-allyl substituted γ-butyrolactones in a one-pot reaction.
Remarkable Molecular Recognition of Dansyl-modified Cyclodextrin Dimer
Authors: Nakamura Michiei , Ikeda Tsukasa , Nakamura Asao , Ikeda Hiroshi , Ueno Akihiko , Toda Fujio
Published: March 2006

Dansyl-modified β-cyclodextrin dimer changes fluorescence intensity depending on the molecular species in aqueous solution and exhibits remarkable molecular recognition for steroidal compounds.
Reaction of Zirconocene Ethylene Complex with Diynes. Formation of Bridged Zirconacyclopentenes
Authors: Takahashi Tamotsu , Kasai Kayoko , Xi Zhenfeng , Denisov Victor
Published: March 2006

Reactions of diynes RCC-X-CCR with zirconocene ethylene complex Cp2Zr(CH2=CH2) were investigated. When X was C6H4 or C4H2S, bridged zirconacyclopentenes were selectively formed. They were easily converted into bridged cyclopentenone derivatives. In the case of (CH2)n groups as X, the reaction products were strongly dependent on the R group.
An Autocatalytic Constant Sensitivity Detection System for Catalysts and Infectors
Authors: Ishihara Masahito , Endo Masatoshi , Igarashi Shukuro , Yotsuyanagi Takao
Published: March 2006

Mathematical model calculation shows that the shape of the reactant concentration-time curves of autocatalytic reaction system at their inflection time is similar to each other even for different initial concentrations of catalysts. It should be of great value as a theoretically infinite sensitivity detection system for catalysts or its infectors. This model has been demonstrated by the use of oxidative destruction of cobalt complexes of 2,4-(2-pyridylazo)benzenediolate and phthalocyaninetetrasulfonate with peroxomonosulfate in aqueous phosphate buffer solution (pH 7) at 25 °C.
Structure and Stereodynamics of N-9-Triptycyl-O-phenylhydroxylamine, an Unusual Product by the Reaction of 9-Nitrosotriptycene and Phenyllithium
Authors: Yamamoto Gaku , Kuwahara Kyoko , Inoue Katsuya
Published: March 2006

Reaction of 9-nitrosotriptycene with phenyllithium gave N-9-triptycyl-O-phenylhydroxylamine (TpNHOPh). The free energy barrier to rotation about the Tp-N bond is 10.9 kcal mol−1 and that to the N-O topomerization is higher than this.
Ring Opening Alkylation of Tetrahydrofuran with Some Heterosubstituted Organolithium Reagents by the Aid of Boron Trifluoride Etherate
Authors: Imai Toshiro , Muramoto Tomoki , Tsuji Takashi
Published: March 2006

Organolithium reagents stabilized by halogeno, thio, silyl, vinyl and/or phenyl substituent(s) can cleave THF effectively under the influence of boron trifluoride etherate at lower temperatures. The softness of these carbanionic reagents seems to be important for the successful reaction.
Electrochemical Reduction of CO2 to Hydrocarbons with High Current Density in a CO2-Methanol Medium
Authors: Saeki Tomonori , Hashimoto Kazuhito , Kimura Naokazu , Omata Koji , Fujishima Akira
Published: March 2006

We reported that CO and methyl formate were the major products in the electrochemical reduction of highly concentrated CO2 in a CO2-methanol medium when tetrabutylammonium salts were used as supporting salts. Here we report that CO2 is reduced efficiently to hydrocarbons when tetraethylammonium perchlorate is used as the salt. CO2 reduction proceeds with a current efficiency of 89.7% at 1  A·cm−2, indicating sufficient mass-transfer of CO2 even at such a high current density.
Multielement Determination of Rare Earth Elements in Rock Sample by Liquid Chromatography / Inductively Coupled Plasma Mass Spectrometry
Authors: Hamanaka Tadashi , Itoh Akihide , Itoh Shinya , Sawatari Hideyuki , Haraguchi Hiroki
Published: March 2006

Rare earth elements in geological standard rock sample JG-1 (granodiolite) issued from the Geological Survey of Japan have been determined by a combined system of liquid chromatography and inductively coupled plasma mass spectrometry.
Solvent Extraction of Transition Metal Ions with Acyclic Polyethers Incorporating Several Heteroatoms and Bearing Heterocyclic Moieties as End Groups
Authors: Sakamoto Hidefumi , Ito Shigeki , Otomo Makoto
Published: March 2006

Nine acyclic polyethers incorporating oxygen, nitrogen and/or sulfur atoms were synthesized, which possess two heterocyclic groups at both ends of an ether chain, and metal ion extractabilities of these compounds were estimated using 1,2-dichloroethane - H2O system. On the solvent extraction of some transition metal ions as the nitrates, Ag+, Cu+ and Hg2+ were more effectively extracted with most of the reagents than the other metal ions. Addition of picrate ion into the aqueous phase of AgNO3 increased Ag+ extractability remarkably.
Dinuclear Manganese(III) Complex with Cyclam-based Dodecadentate Ligand Bearing Schiff-base Pendants (Cyclam = 1,4,8,11-Tetraazacyclotetradecane)
Authors: Mikuriya Masahiro , Yamazaki Yuka
Published: March 2006

Novel dinuclear manganese(III) complex with a new dodecadentate ligand, 1,4,8,11-tetrakis(2-5-chlorosalicylideneaminoethyl)-1,4,8,11-tetraazacyclotetradecane (H4L), [Mn2(L)(CH3COO)2]·2CHCl3 has been synthesized and characterized by X-ray crystallography.
The Photocatalytic Decomposition of Nitric Oxide on the Silver(I) Ion-exchanged ZSM-5 Catalyst
Authors: Matsuoka Masaya , Matsuda Emi , Tsuji Kouji , Yamashita Hiromi , Anpo Masakazu
Published: March 2006

UV irradiation of the Ag+/ZSM-5 catalyst prepared by an ion-exchange method in the presence of NO led to the photocatalytic decomposition of NO into N2, N2O and NO2 at temperatures as low as 298 K. Investigations of in-situ XANES, ESR, and DRS of the Ag+/ZSM-5 catalyst as well as the effective wavelengths of the irradiated UV light indicated that the excited state of the Ag+ ion included within the zeolite cavities plays a significant role in the photocatalytic decomposition of NO molecules.
Highly Thermally-Stable Diels-Alder Adducts of [60]Fullerene with 2-Cycloalkenones and Their Acetals
Authors: Takeshita Hitoshi , Liu Ji-Feng , Kato Nobuo , Mori Akira , Isobe Ryuichi
Published: March 2006

A [4+2] monoadduct with improved thermal stability was obtained from the reaction of [60]fullerene with 2,5-dioxaspiro[4.4]non-6-ene, a masked 4π-component, under high-pressure conditions (300 MPa) at 130 °C in toluene in 85% yield. Hydrolysis of the adduct gave the corresponding ketone, which was also obtained by the reaction of [60]fullerene with cyclopentenone. Even at 150 °C for 15 h, no cycloreversion of the adducts was observed.
α-Helix Propensities of Amino Acids Studied by Multicanonical Algorithm
Authors: Okamoto Yuko , Hansmann Ulrich H E , Nakazawa Takashi
Published: March 2006

We report the results of multicanonical simulations on α-helix propensities of homo-oligomers of nonpolar amino acids. Three characteristic amino acids are considered: alanine (helix former), glycine (helix breaker), and valine (helix indifferent). Starting simulations from completely random initial conformations, we have calculated the average % helix, free energy differences of helix-coil transitions, and the Zimm-Bragg s parameters over a wide range of temperatures. The results are shown to be in good agreement with experiments.
Highly Diastereoselective Synthesis of d-threo- and d-erythro-Sphingosine from Glycidol
Authors: Katsumura Shigeo , Yamamoto Noriyoshi , Fukuda Etsuko , Iwama Seiji
Published: March 2006

d-Threo- and d-erythro-sphingosine, (1) and (2), inhibitors of protein kinase C, have been efficiently synthesized from glycidol through (R)-4-methoxycarbonyloxazolidinone (3) by selective mono-alkylation followed by highly diastereoselective reduction of the tin-substituted pentadecenyl ketone 5.
Histidine Containing Porphyrins Directed for Two Metal Binding Sites
Authors: Ushiyama Masato , Katayama Yoji , Yamamura Takeshi
Published: March 2006

Three types of histidine containing porphyrins different in the protection of imidazole N were synthesized by attaching four l-histidyl-glycyl moieties to α,α,α,α-meso-tetra(o-aminophenyl) porphyrin.
Synthesis of Protected Peptides Containing Phosphoserine with Oxime Resin
Authors: Mihara Hisakazu , Kuwahara Hiromiki , Niidome Takuro , Kanegae Hiroshi , Aoyagi Haruhiko
Published: March 2006

A protected peptide containing phosphoserine was successfully synthesized by the solid-phase method using the oxime resin. The protected phosphopeptide was utilized to further elongation to a longer peptide and conjugation to a template molecule.
Novel Domain Structures in the Mixed Monolayer Films Identified by Atomic Force Microscopy
Authors: Wu Hai-Ming , Xiao Shou-Jun , Lu Zu-Hong , Wei Yu
Published: March 2006

Phase separation was observed by atomic force microscopy in the mixed monolayer films composed of arachidic acid (AA) and 5,10,15-triphenyl-20-(4-dl-α-phenylalanylamindo)phenyl porphyrin (TPPP). Under different preparation conditions, the mixtures exhibit only AA domains or a coexistence structure of AA domains, TPPP domains and downy structures constructed by AA and TPPP together. Different UV-Vis spectra were obtained in the two kinds of phase-separated structures.