bluuebunny/crossref_metadata_2025 huggingface dataset:
Regioselective Reduction of α,β-Unsaturated Carbonyl Compounds to Allylic Alcohols by Vapor Phase Hydrogen Transfer Reaction over MgO-B2O3 Catalyst
Authors: Ueshima Michio , Shimasaki Yuuji
Published: May 2006

Regioselective reduction of α,β-unsaturated carbonyl compounds to the corresponding allylic alcohols was performed effectively by vapor phase hydrogen-transfer reaction over MgO-B2O3 (Mg/B = 100/2) catalyst using secondary alcohols as a hydrogen donor.
Highly Stereodivergent Approach to Both Enantiomers of 4-Substituted β-Lactams via Diastereofacially Controlled Addition of Enolates of t-Butyl Acetate to a Chiral Imine
Authors: Shimizu Makoto , Ukaji Yutaka , Tanizaki Junko , Fujisawa Tamotsu
Published: May 2006

Addition of lithium or triisopropoxytitanium enolate derived from t-butyl acetate to a chiral imine possessing dioxolane ring as a chiral auxiliary gave (3S)-β-amino ester exclusively, whereas chlorozinc enolate underwent re-facial attack to give (3R)-isomer with good selectivity. The β-amino esters thus obtained were readily converted to the corresponding (4S)- and (4R)-β-lactams respectively without loss of the stereochemical integrity at C-4 of the β-lactam rings.
The Cationic Diels-Alder Reaction. Facile Formation of Cationic Species from 2-Oxoalkyl Esters
Authors: Hashimoto Yukihiko , Nagashima Tadamichi , Hasegawa Masaki , Saigo Kazuhiko
Published: May 2006

In the presence of trimethylsilyl trifluoromethanesulfonate (TMSOTf) and methoxytrimethylsilane (MeOTMS), 2-oxopropyl acrylate and 2-oxocyclopentyl acrylate readily form cationic intermediates. The cationic moiety works efficiently as an electron-withdrawing group, and accelerates the Diels-Alder reaction under mild conditions.
Base-Induced Selective Ring Opening of 1-Arylbenzo[b]thiophenium Salts
Authors: Kitamura Tsugio , Takachi Tatsuya , Soda Shin-ichi , Kawasato Hironobu , Taniguchi Hiroshi
Published: May 2006

Reactions of 1-arylbenzo[b]thiophenium salts with methoxide anion in methanol caused the fission of the S+-C(2) bond of the thiophenium ring to produce o-(phenylthio)phenyl-substituted methoxyethenes, allenes, or alkynes.
Catalytic Hydrogenation of Olefins and Acetylenes over C60Pdn
Authors: Nagashima Hideo , Nakaoka Akihito , Tajima Syuji , Saito Yahachi , Itoh Kenji
Published: May 2006

Organopalladium polymers of buckminsterfullerene, C60Pdn, catalyze hydrogenation of olefins and acetylenes at room temperature under a hydrogen atmosphere. The catalytic activity is mainly dependent on the ratio of C60 to Pd in the polymers. Partial hydrogenation of acetylenes is achieved by adding benzylamine as the cocatalyst.
Facile Synthesis of α-Hydroxycarboxylic Acids by Ruthenium-Catalyzed Reduction of Diallyl α-Oxalylcarboxylates with Formic Acid
Authors: Shimizu Isao , Tekawa Masafumi , Maruyama Yooichiroh , Yamamoto Akio
Published: May 2006

Reaction of diallyl α-oxalylcarboxylates with catalytic amounts of ruthenium complexes gave α-hydroxycarboxylic acids in good yields.
An Adduct (1:2) from Diphenylcyclopropenone Oxime and Phenyl Isocyanate
Authors: Gunasekaran Ananthakrishnan , Zhu Nan , Stevens Edwin D , Boyer Joseph H
Published: May 2006

Diphenylcyclopropenone oxime combined with phenyl isocyanate to give 1,2,7-triphenyl-4-[(phenylamino)carbonyl]-5-oxa-4,7-diazaspiro-[2.4]hept-1-en-6-one.
BuSnCl3 Mediated Z-Selective 2-Butenylation and erythro-Selective 1-Methyl-2-propenylation of Aldehydes by 1-(Tributylstannyl)-2-butene
Authors: Miyake Hideyoshi , Yamamura Kimiaki
Published: May 2006

Butyltin trichloride mediated reaction of 1-(tributylstannyl)-2-butene with aldehydes is described. This reaction is useful as a stereoselective method for (Z)-2-butenylation and erythro-1-methy-2-propenylation of aldehydes.
Microviscosity in AOT Reversed Micellar Core Determined with a Viscosity-sensitive Fluorescence Probe
Authors: Hasegawa Masatoshi , Sugimura Tokuko , Kuraishi Kazuhiro , Shindo Yoich , Kitahara Ayao
Published: May 2006

Microviscosity in AOT reversed micellar core, η, was determined with a viscosity-sensitive fluorescent probe, auramine O (AuO), as a function of R ( = [H2O]/[AOT]). With the increase in R, The η decreased rapidly in the region of R < 10, and leveled at about R = 20. AuO molecules located in the vicinity of water/surfactant interface suggested the presence of water bound to polar heads of AOT.
Lewis Acid-Promoted Reaction of β,β-Difluorinated N,O-Acetal with Silylated Nucleophiles
Authors: Tsukamoto Takashi , Kitazume Tomoya
Published: May 2006

Lewis acid-promoted reaction of ethyl 3-ethoxy-2,2-difluoro-3-(dimethylamino)propionate (1) with some silylated nucleophiles afforded β,β-difluoroamines in good yields. The formation of iminium ion intermediate from 1 and BF3·OEt2 was confirmed by 19F and 13C NMR spectroscopy.
Cobalt(II) Porphyrin-Catalyzed Oxidation of Olefins to Ketones with Molecular Oxygen and Triethylsilane in 2-Propanol
Authors: Matsushita Yoh-ichi , Matsui Takanao , Sugamoto Kazuhiro
Published: May 2006

An efficient conversion of olefins to ketones was achieved by the use of molecular oxygen and triethylsilane in the presence of a catalytic amount of cobalt(II) complex of porphyrin. The oxidation was accelerated remarkably in alcohols and had chemoselectivity for conjugated olefins.
Surface-Enhanced Infrared and Raman Studies of Electrochemical Reduction of Self-Assembled Monolayers Formed from p-Nitrohiophenol at Silver
Authors: Matsuda Naoki , Yoshii Katsumasa , Ataka Ken-ichi , Osawa Masatoshi , Matsue Tomokazu , Uchida Isamu
Published: May 2006

The electrochemical reduction of self-assembled monolayers formed from p-nitrothiophenol has been studied in situ by surface-enhanced infrared (IR) absorption and Raman scattering (SEIRA and SERS, respectively) spectroscopies. The sensitivity of SEIRA spectroscopy is 20 times higher than that of IR reflection-absorption (IR-RAS) spectroscopy. Combined use of SEIRA and SERS spectroscopies is useful for detailed analyses of electrode reactions and vibrational properties of adsorbed molecules.
A Convenient Synthesis of Unsymmetrical Tellurides by a Sequential Reductive Cleavage of Bis(N,N-dimethylcarbamoyl) Ditelluride
Authors: Shimada Kazuaki , Oikawa Seiji , Takikawa Yuji
Published: May 2006

Bis(N,N-dimethylcarbamoyl) ditelluride was converted to unsymmetrical tellurides possessing various substituents by a convenient stepwise reduction-alkylation or reduction-addition sequence.
First Preparation and Reactions of S,S-Diaryl-S-fluorothiazynes, Ar2SF(N)
Authors: Yoshimura Toshiaki , Kita Hiroshi , Takeuchi Kyu , Takata Eiichi , Hasegawa Kiyoshi , Shimasaki Choichiro , Tsukurimichi Eiichi
Published: May 2006

S,S-Diaryl-S-fluorothiazynes, Ar2SF(≡N), were prepared by the reaction of S,S-diaryl-N-bromosulfilimines with tetrabutylammonium fluoride. The thiazyne structure was assigned by the spectral data, physical properties, and is consistent with reactions with sodium alkoxides and primary amines. The thiazyne prepared previously by Clifford et al. is doubtful.
A New Oxidative Se-Dealkylation in Seleno-Pummerer Reaction of 1,8-Bis(methylseleno)naphthalene and Naphtho[1,8-b,c]-1,5-diselenocin Induced by Peri-Selenium Participation
Authors: Fujihara Hisashi , Saito Rei , Yabe Masayoshi , Furukawa Naomichi
Published: May 2006

A new type of oxidative Se-dealkylation reaction was found in either the reaction of 1,8-bis(methylseleno)naphthalene and naphtho[1,8-b,c]-1,5-diselenocin with benzoyl peroxide or the reaction of their Se-oxides with carboxylic acid anhydrides.
Formation of Rh Carbonyl Cluster Species and Its Conversion into Metal Particles during Exposure of Rh/Active Carbon to Carbon Monoxide Revealed by EXAFS and TPD Techniques
Authors: Takahashi Nobuo , Takeyama Terushige , Fujimoto Toshiyuki , Fukuoka Atsushi , Ichikawa Masaru
Published: May 2006

The results obtained by EXAFS and TPD of CO techniques clearly showed that Rh6(CO)16 is formed by the exposure of partially reduced Rh/active carbon to CO at 353 K, and further converted into metallic rhodium particles at 473 K.
Diastereoselective Synthesis of β-Amino Esters by the Lewis Acid-Mediated Reaction of N-Tosyl Aldimines with Ketene Bis(trimethylsilyl) Acetals
Authors: Shimada Shigeru , Saigo Kazuhiko , Abe Masanori , Sudo Atsushi , Hasegawa Masaki
Published: May 2006

In the presence of titanium(IV) bromide, N-tosyl aldimines smoothly reacted with ketene bis(trimethylsilyl) acetals at low temperature, and upon esterification anti-β-amino esters were obtained selectively.
Highly Regioselective Pinacol Rearrangement of Sulfenylmethylated Glycols
Authors: Kudo Kazuaki , Saigo Kazuhiko , Hashimoto Yukihiko , Saito Katsuyuki , Hasegawa Masaki
Published: May 2006

Pinacol rearrangement of glycols having a sulfenylmethyl group smoothly proceeded with high regioselectivity to give ketones which were derived by the elimination of the β hydroxyl group to the sulfur atom. This selectivity is due to the neighboring group participation of the sulfenyl group.
Inner Rotation of the Exocyclic C=C Bonds of Methyl 2-Cyano-(2-methylcyclohepta[b]thiophen-8-ylidene)acetate and Methyl 2-Cyano-(1,2-dimethylcyclohepta[b]pyrrol-8-ylidene)acetate
Authors: Ikeda Yukari , Yin Bing Zhu , Kato Nobuo , Mori Akira , Takeshita Hitoshi
Published: May 2006

The rotational barrier of the exocyclic C=C bonds of heptafulvenes condensed with a hetero aromatic ring is dependent on electron donating ability of heterocycles and on the steric repulsion around the exocyclic C=C bond. The large negative entropies of activation are consistent with an extensively polarized transition state.
Stereochemical Studies of Chiral Nonconjugated Carbanions. Asymmetric Alkylation of Aldehydes with Sulfur-Substituted Carbanions of Chiral α-(1,3-Dithian-2-yl) Acetals
Authors: Chikashita Hidenori , Yuasa Tsutomu , Itoh Kazuyoshi
Published: May 2006

A new type of asymmetric induction based on the nucleophilic addition of sulfur-substituted nonconjugated carbanions produced from a variety of chiral α-(1,3-dithian-2-yl) acetals to achiral aldehydes was studied. The reaction with the carbanion of the chiral acetal derived from (4R,5R)-3,6-diethyl-3,6-dimethoxy-4,5-octanediol showed the best stereoselectivity (ds = 2.4:1-6.3:1) producing a chiral secondary-alcohol center.
X-Ray Structure of [Be{B(pz)4}2] and [Be3(OH)3{HB(pz)3}3]. Different Structures and Multiple-Point Bindings in Polypyrazolylborate Complexes
Authors: Sohrin Yoshiki , Kokusen Hisao , Kihara Sorin , Matsui Masakazu , Kushi Yoshihiko , Shiro Motoo
Published: May 2006

Two novel polypyrazolylborate complexes of beryllium, [Be{B(pz)4}2] (1) and [Be3(OH)3{HB(pz)3}3] (2), have been prepared in aqueous solution, and their X-ray crystal structures have been determined. Complex 1 contains a tetrahedral Be2+ with each ligand having bidentate coordination. In complex 2, each HB(pz)3− is attached to a cyclic [Be3(OH)3]3+ moiety by two Be-N coordination bonds and one OH-N hydrogen bond.
Multi-Layered Thin Films of Ordered Alumina Particles
Authors: Tsutsumi Nobuo , Sakata Kanji , Kunitake Toyoki
Published: May 2006

Multi-layered alumina thin films with crystalline anisotropy and high surface area were prepared from ultra-fine particles of alumina using a multi-bilayer cast film of a double-chain ammonium amphiphile as a molecular template.
An Efficient Deoxysugar Synthesis using Bu4NBH4 via an SN2 Reduction
Authors: Sato Ken-ichi , Hoshi Toshio , Kajihara Yasuhiro
Published: May 2006

Deoxysugar derivatives were prepared from the corresponding triflate, tosylate, halogen, and epoxide derivatives. Employing the tetrabutylammonium tetrahydroborate reagent, the deoxygenation proceeds via an SN2 type displacement in good yield.
16-Electron Half-sandwich Ru(II)—Thiolate Complexes, Ru(SAr)2(η6-p-cymene) (Ar = 2,6-dimethylphenyl and 2,4,6-triisopropylphenyl)
Authors: Mashima Kazushi , Mikami Aki , Nakamura Akira
Published: May 2006

Treatment of [RuCl2(p-cymene)]2 with sodium 2,6-dimethylbenzenethiolate or sodium 2,4,6-triisopropylbenzenethiolate in methanol afforded a mononuclear five-coordinated ruthenium thiolate complex, Ru(SAr)2(p-cymene) (2a: Ar = 2,6-dimethylphenyl; 2b: 2,4,6-triisopropylphenyl), whose structure is determined by X-ray analysis of 2a.
Monolayer of Lithocholic Acid by Chemical Reaction on Silicon Crystal Surface
Authors: Sano Kenji , Machida Shigeru , Sasaki Hideyuki , Yoshiki Masahiko , Mori Yasushi
Published: May 2006

The reaction of lithocholic acid with silane coupling agent on a Si crystal surface was analyzed with FT-IR(ATR), XPS, and contact angle. The generation of amide bonds within 1nm of the Si surface was confirmed with XPS. The yield of amide was 84%. An abnormal IR absorption was observed in the amide band region.
Cycloreversion of Electron-Rich Quadricyclane Initiated by Metal Oxides
Authors: Yamashita Asami , Hasebe Kiyoshi , Hirao Ken-ichi
Published: May 2006

Electron-rich quadricyclane is effectively converted to the corresponding norbornadiene by various metal oxides, while conversion of parent quadricyclane into norbornadiene is inefficient.
Convenient One-Pot Synthesis of Sulfonyl Chlorides from Thiols Using Sulfuryl Chloride and Metal Nitrate
Authors: Park Young Jun , Shin Hyun Ho , Kim Yong Hae
Published: May 2006

Various sulfonyl chlorides were obtained in excellent yields by the reaction of alkyl and aryl thiols with sulfuryl chloride in the presence of metal nitrate under mild condition in aprotic solvents such as acetonitrile and N,N-dimethylformamide.
Abnormal Four-Membered Ring Formation in Intramolecular Radicalic Cyclization. High Stability of the Alkyl Radical Substituted with Methylthio and p-Tolylsulfonyl Groups
Authors: Ogura Katsuyuki , Sumitani Naoko , Kayano Akio , Iguchi Hirotaka , Fujita Makoto
Published: May 2006

Treatment of 5-iodo-1-(methylthio)-1-(p-tolylsulfonyl)-1-pentene with (n-Bu)3SnH and AIBN gave [(methylthio)(p-tolylsulfonyl)methyl]cyclobutane. This is due to the stability of an intermediary radical attached to methylthio and p-tolylsulfonyl groups.
Density Functional Calculations on the Geometries and Dissociation Energies of [M(H2O)6]2+ Ions. M2+ = Cr2+, Mn2+, Fe2+, Co2+, Ni2+, Cu2+, and Zn2+
Authors: Waizumi Kenji , Ohtaki Hitoshi , Masuda Hideki , Fukushima Nobuhiro , Watanabe Youichi
Published: May 2006

Full geometry optimizations have been carried out on high-spin hexaaqua complexes of Cr2+, Mn2+, Fe2+, Co2+, Ni2+, Cu2+, and Zn2+ by the local spin density functional method with non-local corrections using Gaussian-type basis sets. The octahedral molecular arrangement around the Mn2+, Ni2+, and Zn2+ ions optimized were regular, whereas those around the Cr2+, Fe2+, Co2+, and Cu2+ ions were distorted with significant differences in the three kinds of M-O distances. The Jahn-Teller distortion for the Fe2+ and Co2+ complexes was firstly found in the field of computational geometry optimization.
Stereoselective Synthesis of (±)-Isonitramine and (±)-Sibirine
Authors: Fujii Masayuki , Kawaguchi Koichi , Nakamura Kaoru , Ohno Atsuyoshi
Published: May 2006

Spirocyclic alkaloids, (±)-isonitramine and (±)-sibirine were synthesized in high overall yields via a chemoselective reduction by Hantzsch ester (HEH), a coenzyme NADH model compound.
Na+-Catalyzed Reduction of Semiquinone Radical Anions by NADH Analogues
Authors: Fukuzumi Shunichi , Tokuda Yoshihiro
Published: May 2006

Stable radical anions such as p-chloranil radical anion (Cl4Q−•) are reduced by NADH analogues, 1-benzyl-1,4-dihydronicotinamide (BNAH) and 10-methyl-9,10-dihydroacridine (AcrH2), to yield the corresponding hydroquinone anions. The addition of NaClO4 to the BNAH-Cl4Q−• system results in a significant increase in the rate of the one-electron reduction of Cl4Q−•, while no acceleration effect has been observed by the addition of Bu4NClO4.
Transformation of Dinucleoside S-Aryl Phosphorothioates into the Corresponding O-Alkyl Phosphates by Use of Tributyltin Alkoxides
Authors: Ohuchi Shokichi , Ayukawa Hiroshi , Hata Tsujiaki
Published: May 2006

Several alkyl dinucleoside phosphotriesters were easily obtained by use of the reaction of S-aryl dinucleoside phosphorothioates with tributyltin alkoxides. This reaction proceeds at room temperature under neutral conditions.
Facile Chlorination of Sugar Moiety of Nucleosides by Use of Tris(2,4,6-tribromophenoxy)dichlorophosphorane
Authors: Ohuchi Shokichi , Singh Ramendra K , Wada Takeshi , Hata Tsujiaki
Published: May 2006

A versatile chlorinating reagent, tris(2,4,6-tribromophenoxy)dichlorophosphorane was applied for 5′- and 3′-chlorination of nucleosides. It was found that the reaction proceeded via SN2 mechanism.
Fluoroselenenylation of Alkynes
Authors: Usuki Yoshinosuke , Iwaoka Michio , Tomoda Shuji
Published: May 2006

Benzeneselenenyl fluoride equivalent was generated in situ by the reaction of silver(I) fluoride with benzeneselenenyl bromide in dichloromethane under ultrasound irradiation. Treatment of internal alkynes with this reagent afforded 2-fluoro-1-alkenyl phenyl selenides in moderate yields.
A Stereocontrolled Construction of 2-Deoxy-β-glycosidic Linkages via 1,2-trans-β-Glycosidation of 2-Deoxy-2-[(p-methoxyphenyl)thio] glycopyranosyl N,N,N′,N′-Tetramethylphosphoroamidates
Authors: Hashimoto Shun-ichi , Yanagiya Yuki , Honda Takeshi , Ikegami Shiro
Published: May 2006

A stereocontrolled synthesis of 2-deoxy-β-glycosides has been achieved by developing a salient 1,2-trans-glycosidation method with 2-deoxy-2-[(p-methoxyphenyl)thio]glycopyranosyl N,N,N′,N′-tetramethylphosphoroamidates as glycosyl donors followed by a reductive removal of the p-methoxyphenylthio group with Raney nickel. The p-methoxyphenylthio group equatorially disposed at C-2 has proven to be an excellent stereodirecting auxiliary.
Platinum- and Palladium-Isonitrile Complexes. A New Family of Organometallic Liquid Crystalline Material
Authors: Kaharu Takeshi , Takahashi Shigetoshi
Published: May 2006

The title complexes having phenylisonitrile derivatives as a ligand show mesomorphic properties in a wide temperature range.
Synthesis and Electrical Conductive Properties of Polymeric Metalloporphyrins
Authors: Wang Yunpu , Wang Rongming
Published: May 2006

The polymeric porphyrin film has been prepared by interfacial polymerization of tetrakis (4-hydroxy phenyl) porphyrin (THPP) with terephthalyl chloride. The spectra and electrical properties of its complexes with transition metal (Cu, Co, Zn) have been studied. The polymer exhibits semi-conducting property (σRT = 4.83 × 10−4 S · cm−1) after doping with iodine.
Reaction of Metastable Ar Atoms with cis- and trans-2-Butene in Flow System
Authors: Takahasi Makoto
Published: May 2006

The chemical behavior of cis- and trans-2-butene has been investigated in a flow system with metastable Ar atoms. In the case of cis-2-butene, split of the C–C single bond between CH3 and CH=CH was observed, while in the case of trans-2-butene no reaction was observed. Geometrical isomerization of neither cis- nor trans-2-butene was observed.
Carboxylation of Benzoic Acid Using Cyclodextrin as Catalyst
Authors: Hirai Hidefumi , Mihori Hisashi
Published: May 2006

Benzoic acid is found to undergo carboxylation by warming with carbon tetrachloride in aqueous alkali in the presence of copper powder with β-cyclodextrin as catalyst. The reaction under mild conditions gives terephthalic acid in good yield with high selectivity.
Preparation of Nonaqueous Dispersion of Colloidal Silver by Phase Transfer
Authors: Hirai Hidefumi , Aizawa Hotaka , Shiozaki Hyouya
Published: May 2006

Colloidal silver particles dispersed in water are found to be transferred into a nonaqueous liquid by the addition of sodium chloride to an emulsion of the nonaqueous liquid in the aqueous dispersion of colloidal silver with sodium oleate. The colloidal dispersions of silver in cyclohexane, n-hexane and benzene are prepared by phase transfer using sodium oleate and sodium chloride.
A Ketyl Radical Probe Experiment. The Reactions of o-Halobenzophenones with Various Wittig Reagents
Authors: Yamataka Hiroshi , Ando Katsuhiro , Takatsuka Tsutomu , Hanafusa Terukiyo
Published: May 2006

The ketyl radical probe experiments of o-, m-, or p-bromobenzophenone and iodobenzophenone with nonstabilized, semistabilized, and stabilized ylides in THF and [2H8]THF suggested the presence of radical anion species of sufficient lifetime in the reaction with a nonstabilized ylide.
Compositional Variation of Ionizable Crown Ether-Alkali Metal Ion Complexes in the Solvent Extraction Using Several Extraction Solvents
Authors: Sakamoto Hidefumi , Goto Hiroki , Doi Kunio , Otomo Makoto
Published: May 2006

Novel benzo-15-crown-5 and 18-crown-6 derivatives bearing an ionizable hydrazone group were synthesized and complex formation equilibria of the compounds with alkali metal ions in solvent extraction were evaluated spectrophotometrically. Formation of 2:2 complexes of the crown ethers with metal ions was observed using chloroform as an extraction solvent.
Synthesis and Structure of a Disulfido-Bridged Mixed-Valent Ru(II)Ru(III) Complex [{Ru(AN)3(TMP)2}2(μ-S2)](PF6)3 (AN = acetonitrile, TMP = P(OMe)3)
Authors: Matsumoto Takaya , Matsumoto Kazuko
Published: May 2006

The first structural analysis of a S22−-bridged Ru(II)Ru(III) compound is reported. The compound was isolated from an acetonitrile solution of [{RuCl(TMP)2}2(μ-Cl)2(μ-S2)] with the addition of NaPF6. The two Ru atoms are equivalent and are bridged by a S22− ligand in trans positions.
Electron-Transfer Quenching and Thermal Backward Electron-Transfer Reactions of Zinc Myoglobin Controlled by Conformational Change
Authors: Tsukahara Keiichi , Okada Mihoko
Published: May 2006

Both photoinduced electron-transfer and thermal backward electron-transfer reactions of zinc myoglobin with cationic quenchers were bimolecular steps and the reaction rates were insensitive to the driving force of reactions, suggesting that the reactions are controlled by conformational changes of zinc myoglobin.
A New Method for Functionalization of Si-Si Bond-Containing Polymers by Insertion of Acetylenes into Polymer Backbones
Authors: Yamashita Hiroshi , Tanaka Masato
Published: May 2006

Partial insertion of functionalized acetylenes RC≡CH (R = 4-Me2NC6H4, 4-pyridyl, Me3SiOCH2) into Si-Si bonds of a poly[p-(disilanylene)phenylene] (1) and poly(methylpropylsilylene) smoothly proceeded by Pd(dba)2-2P(OCH2)3CEt (dba = dibenzylideneacetone) catalyst. A modified polymer of 1 with a (4-dimethylaminophenyl)vinylene group showed higher conductivity than 1 when doped with iodine.
Preparation of Poly(2,5-selenophenediyl-vinylene) Film by Sulfonium Salt Method
Authors: Iwatsuki Shouji , Kubo Masataka , Kamei Nobuaki
Published: May 2006

Soluble poly(2,5-selenophenediyl-methoxyethylene) was prepared by the reaction of (2,5-selenophenediyl dimethylene) bis(dimethylsulfonium bromide) with a base in a mixture of methanol and water. Its cast film was heated at 200 °C under nitrogen to obtain poly(2,5-selenophenediyl-vinylene) film.
Recovery of Rare Metals from the Sludge of Samarium-Cobalt Magnetic Alloy by a Chemical Vapor Transporting Method
Authors: Murase Kuniaki , Machida Ken-ichi , Adachi Gin-ya
Published: May 2006

A dry process using chemical vapor transporting technique along temperature gradient was investigated for the recovery and recycling of rare metals from the sludge of Sm-Co binary alloys. For the permanent magnetic alloy sludge of Sm2Co17, the Sm and Co elements were effectively separated in the form of anhydrous chlorides with the purity higher than 99%.
Synthesis, Structure, and Reactions of a 10-Sb-4 Type Antimony Ate Complex
Authors: Akiba Kin-ya , Nakata Hisashi , Yamamoto Yohsuke , Kojima Satoshi
Published: May 2006

A 10-Sb-4 type organoantimony ate complex was prepared from hexafluorocumyl alcohol and SbCl3 as an air and water stable compound. Its X-ray structural analysis revealed a distorted pseudo-trigonal bipyamidal structure. The compound reacted with both alkyl halides and organolithium reagents to yield neutral 10-Sb-5 compounds.
Synthesis, Structure, and Reactions of 10-Sn-5 Organotin Ate Complexes
Authors: Akiba Kin-ya , Ito Yasushi , Kondo Fumihiro , Ohashi Noriko , Sakaguchi Akira , Kojima Satoshi , Yamamoto Yohsuke
Published: May 2006

Stable anionic 10-Sn-51) species, tetraalkylammonium bis[α,α-bis(trifluoromethyl)benzenemethanolato(2−)-C2,O]alkylstannates(1−) [2a (R = Ph), 2b (R = p-CH3C6H4), 2c (R = n-Bu), and 2d (R = Me)], were prepared. Reaction of 2a and 2b with sulfuryl chloride gave chlorostannate (3a), which could be converted to fluorostannate (3b). 3a and 3b reacted with organolithium reagents to give 2. The X-ray crystallographic analysis of 3b-n-Bu4N+ revealed a distorted trigonal bipyramidal structure.
Benzene or Naphthalene Ring-fused Mono-Substituted Type Tetraazaoctaphenylporphyrin Zinc Complexes
Authors: Kobayashi Nagao , Ashida Tohru , Hiroya Kou , Osa Tetsuo
Published: May 2006

A zinc tetraazaoctaphenylporphyrin (ZnTAP) and benzene or naphthalene ring-fused unsymmetrcal ZnTAPs are synthesized and characterized by UV-visible absorption, emission, excitation, and magnetic circular dichroism (MCD) spectroscopy together with cyclic and differential pulse voltammetry. With lowering of the molecular symmetry, both the energy differences, between the Soret and Q bands and the splitting of the Q0-0 band increase while the quantum yield (φF) of the fluorescence decreases.
Ferromagnetically Coupled Dimanganese(III) Complex and Antiferromagnetically Coupled Diiron(III) Complex with Unsymmetrical Ligands
Authors: Mikuriya Masahiro , Yamato Yo , Tokii Tadashi
Published: May 2006

Binuclear iron(III) and manganese(III) complexes with 1-salicylideneamino-3-salicylamino-2-propanol (H3L), [Mn2(L)2]·2CH3CN and [Fe2(L)2]·2CH3CN, have been prepared and characterized by X-ray structure analysis and magnetic susceptibilities (80–300 K).
Synthesis of Oxazepinones from Vinyloxiranes and Chlorosulfonyl Isocyanate
Authors: Daniel Joseph , Shukla Deepti , Dhar Durga Nath
Published: May 2006

A facile synthesis of oxazepinone derivatives is reported by the interaction of vinyloxiranes and chlorosulfonyl isocyanate. A 1,5 to 1,7-dipolar rearrangement of the initially formed adduct, followed by ring closure is proposed.
Synthesis and Structural Analysis of Three-bridged [2.2.n](1,2,4)- and [4.4.n](1,2,4)-Cyclophanes
Authors: Okada Yukihiro , Ishii Fuyuhiko , Akiyama Isao , Nishimura Jun
Published: May 2006

Three-bridged [2.2.n](1,2,4)cyclophanes 4a and b were obtained by [2+2] photocycloaddition of divinylmetacyclophanes in 21 and 86% yields, respectively. Birch reduction of cyclophanes 4a and b gave [4.4.n](1,2,4)cyclophanes in 45–61% yields.
Heterocyclic o-Quinones. Mediator for Electrochemical Oxidation of NADH
Authors: Itoh Shinobu , Fukushima Hajime , Komatsu Mitsuo , Ohshiro Yoshiki
Published: May 2006

Heterocyclic o-quinones such as phenanthrolinequinone derivatives are demonstrated to act as a mediator in electrochemical oxidation of NADH, which can be used as an NAD+-recycling system for HLADH-catalyzed oxidation of alcohols.
Synthesis of the C- and D-Ring System of Hemibrevetoxin-B
Authors: Feng Fei , Murai Akio
Published: May 2006

The C- and D-ring system of hemibrevetoxin-B, which has been isolated from the red tide organism, Gymnodinium breve, has been synthesized in a racemic form on the basis of our new methodology involving the general conversion of medium sized lactone into the corresponding cyclic ether.
Oxidative Dimerization of Lithium-Enolates of Esters Promoted by TitaniumTetrachloride
Authors: Ojima Iwao , Brandstadter Stephan M , Donovan Robert J
Published: May 2006

Oxidative dimerization of lithium ester enoalates is effectively promoted by TiCl4, which serves as a new and efficient synthetic method. Mechanistic study indicates that the reaction proceeds via a radical-like mechanism, but it is not a free radical process.
Reaction of Tetrachalcogenastannolanes with Triphenylphosphine. A Novel Mode of Generation for Overcrowded Stannanethiones and Stannaneselones
Authors: Tokitoh Norihiro , Matsuhashi Yasusuke , Goto Midori , Okazaki Renji
Published: May 2006

Dechalcogenation of overcrowded 1,2,3,4,5-tetrachalcogenastannolanes with triphenylphosphine resulted in the formation of the corresponding 1,3,2,4-dichalcogenadistannetanes via [2+2]cycloaddition of intermediary stannanethione and stannaneselone. Molecular structures of the newly obtained 1,3,2,4-dichalcogenadistannetanes were examined by X-ray analysis.
1,2,3,4,5,6,7,8-Octathionane, a Novel Cyclic Polysulfide. Synthesis and Crystal Structure
Authors: Tokitoh Norihiro , Takeda Nobuhiro , Imakubo Tatsuro , Goto Midori , Okazaki Renji
Published: May 2006

Thermal reaction of a sterically bulky diazomethane with elemental sulfur in benzene afforded a novel cyclic polysulfide, 1,2,3,4,5,6,7,8-octathionane (1). Molecular structure of 1 was determined by X-ray crystallographic analysis and the geometry of its CS8 ring of 1 was compared with that of the theoretically optimized cyclononasulfur (S9).
Synthesis and Unusual Photochemical Reaction of Highly Congested 2,4,6-Tri-t-butylstyrene Episulfides
Authors: Kawashima Takayuki , Watanabe Soichiro , Okazaki Renji
Published: May 2006

Title compounds were synthesized by the reaction of 2,4,6-tri-t-butylthiobenzaldehyde with some diazomethanes. The photolysis of the most sterically congested episulfide obtained from t-Bu2CN2 gave an unusual product resulting from 1,2-migration of t-butyl group instead of the corresponding styrene, a normal photo-product, the corresponding styrene, together with Dewar benzene and benzothiophene derivatives.
The Phospha-Cope Rearrangement of 3-Phospha-1,5-hexadiene Derivatives Bearing a Hydroxyl Group
Authors: Kawashima Takayuki , Park Dae Jong , Murata Shinobu , Okazaki Renji , Inamoto Naoki
Published: May 2006

The title phospha-Cope rearrangement gives the corresponding cyclic phosphonates or phosphinates in 30 to 100% yields. Studies on solvent effects and kinetic isotope effects using the deuterated derivatives strongly support that there is a preequilibrium between tetracoordinate and pentacoordinate structures, followed by the rate determining phospha-Cope rearrangement.
Enantioselective Oxidation of Sulfinic Acid Esters with the Aid of a Microorganism
Authors: Kawasaki Takayasu , Watanabe Naoyuki , Sugai Takeshi , Ohta Hiromichi
Published: May 2006

Incubation of racemic arenesulfinic acid esters with a bacterial strain gave the corresponding sulfonates leaving behind optically active sulfinates via enantioselective oxidation. The substrates having longer alkyl chains as alcohol component were smoothly oxidized, and electron donating substituents on aromatic ring accelerated the reaction.
Entrapment of Glucose Oxidase in Silica Gel by the Sol-Gel Method and Its Application to Glucose Sensor
Authors: Tatsu Yoshiro , Yamashita Keishi , Yamaguchi Muneaki , Yamamura Soichiro , Yamamoto Hitoshi , Yoshikawa Susumu
Published: May 2006

The polymerization of tetraethyl silicate in the presence of glucose oxidase gave the silica gel with the enzymatic activity. As raising the aging temperature, the yield increased but the activity decreased. The flow injection-sensor constructed with the oxygen electrode covered by glucose oxidase-entrapped silica gel responded to glucose of physiological concentration.
Determination of CMC Based on Measurement of Liquid Junction Potential
Authors: Yamauchi Akira , Inoue Minako
Published: May 2006

A novel method for the determination of the critical concentration of a micelle formation (hereafter designated as CMC) based on the measurement of liquid junction potential was proposed in this study. In addition, the transport numbers of surfactant ions which express the dynamic behavior in surfactant solution were estimated.
Tautomerizaton of 2-Carboxy-1,3-dibenzo[a,c]tropolone in the Solid State. Possibility of a Symmetrical Structure of the Enol Form
Authors: Mochida Tomoyuki , Shinagawa Hideyuki , Izuoka Akira , Sugawara Tadashi
Published: May 2006

Crystal structure of 2-Carboxy-1,3-dibenzo[a,c]tropolone (4) is characterized by intramolecular hydrogen bonds with d(O···O) of 2.400(5) Å, which is one of the shortest distances reported for 3-hydroxyenones. An averaged structure of 4 suggested by solid state 13C (CP/MAS) NMR may be attributed to a genuine symmetry rather than a dynamically averaged one. Namely, the tautomer may have a symmetric structure resulting from the extremely short O···O distance.
Magnetic Property of 1,3,5-Tris(4′,4′,5′,5′-tetramethylimidazolin-2′-yl)benzene 3′,3′′,3′′′-Trioxide 1′,1′′,1′′′-Trioxyl in 1 : 1 Mixed Crystals with 1,3,5-Trinitrobenzene
Authors: Izuoka Akira , Fukada Masanori , Sugawara Tadashi , Sakai Masahiro , Bandow Shunji
Published: May 2006

Temperature dependence of magnetic susceptibility of 1,3,5-tris(4′,4′,5′,5′-tetramethylimidazolin-2′-yl)benzene 3′,3′′,3′′′-trioxide 1′,1′′,1′′′-trioxyl was measured by a Faraday type magnetic balance on a neat sample and on mixed crystals with 1,3,5-trinitrobenzene (1:1). While the triradical in a powdered sample behaves like three monoradicals (3 × S = 1/2) following the Curie-Weiss law (θ = −14 K), the intramolecular ferromagnetic coupling (J/kB = 23 K) becomes detectable in the mixed crystals.
Synthesis of Deeply Colored Soluble Polyacetylenes from 1-Ethynylnaphthalene and 3,6-Dibutyl-9-ethynylphenanthrene
Authors: Yamaguchi Masahiko , Hirama Masahiro , Nishihara Hiroshi
Published: May 2006

Deeply colored soluble polyacetylenes were synthesized from 1-ethynylnaphthalene and 3,6-dibutyl-9-ethynylphenanthrene by employing a tungsten (IV) catalyst. Since 2-ethynylnaphthalene gave the less conjugated polymer, connection mode of the aromatic pendants was found to be essential for maintaining the conjugated structure of the polyene chain. Electrochromic properties of poly(1-ethynylnaphthalene) were also studied.
Promotive Effects of the Addition of Alkaline Earth Metals to Ce-ZSM-5 Catalyst for the Reduction of Nitrogen Monoxide in the Presence of Propene and Oxygen
Authors: Yokoyama Chikafumi , Misono Makoto
Published: May 2006

The addition of alkaline earth metals to Ce-exchanged ZSM-5 enhanced remarkably the catalytic activity for the removal of nitrogen monoxide (1000 ppm) in the presence of propene (500 ppm) and oxygen (2%). The activity was great even at the space velocity of 105 h−1.
A Facile Preparative Method of C-Nucleosides
Authors: Togo Hideo , Ishigami Sachiko , Yokoyama Masataka
Published: May 2006

Facile and general preparative method of C-nucleosides has been achieved via 4 steps starting from 2-deoxy-D-ribose. The essential step in this method is the use of radical coupling reaction of 2-deoxy-D-ribofuranosyl radical derivative and some heteroaromatic bases.
Alkylation of Heteroaromatic Bases with Diphenylselenium Diacyloxylate
Authors: Togo Hideo , Miyagawa Nobukazu , Yokoyama Masataka
Published: May 2006

Heteroaromatic bases were alkylated with selenuranes, which were formed by the reaction of diphenylselenoxide and carboxylic anhydrides, under photoirradiation conditions. This reaction was presumed to proceed via a radical pathway accompanying decarboxylation.
Polypeptide Formation from Asparagine-Containing Dipeptides in Aqueous Solution upon Heating
Authors: Munegumi Toratane , Suzuki Naoko , Tanikawa Naoya , Harada Kaoru
Published: May 2006

Heating the aqueous solutions of asparagine-containing dipeptides in which asparagine locates at their C-terminal gave sequential polypeptides having the molecular weight up to 3000–5000.
A Remarkable Sensitivity of CaO-loaded In2O3 Element to CO2 Gas in the Presence of Water Vapor
Authors: Mizuno Noritaka , Kato Kazuyoshi , Yoshioka Tetsunori , Iwamoto Masakazu
Published: May 2006

The In2O3 element modified by 5.5 wt% CaO showed the sensitivities (the ratio of resistance of the element in air containing no CO2 to that in a diluent CO2 gas) to 2080 ppm CO2 as high as 12.9, 9.9, and 6.6 in the presence of 0, 1.1, and 1.8 vol% water vapor, respectively.
pH-Responsive Molecular Recognition by a Water-soluble Cyclophane Bearing l-Aspartate Moieties
Authors: Kikuchi Jun-ichi , Egami Kazuko , Suehiro Kazuaki , Murakami Yukito
Published: May 2006

A novel water-soluble cyclophane host bearing four pH-sensitive tentacles was prepared from 1,6,20,25-tetraaza[6.1.6.1]paracyclophane and l-aspartic acid. The host was found to exist primarily as tetracationic and tetraanionic species in pH ranges below 1 and above 11, respectively, and to exhibit pH-responsive molecular recognition toward various aromatic guests.
The X-Ray Crystal Structure of a Charge-transfer Complex Derived from a Non-planar, Bulky, and Conformationally Flexible Donor Compound
Authors: Hayashi Naoto , Mazaki Yasuhiro , Kobayashi Keiji
Published: May 2006

Bis(9-hydroxyfluorenyl)-substituted dithienothiophene afforded a crystalline charge-transfer complex with 2,3-dichloro-5,6-dicyanobenzoquinone. The crystal structure was revealed by an X-ray analysis to be composed of a cage-like dimeric unit of the donor molecules which are alligned in a segregated columnar stack.
Monohalogenation of Zirconacyclopentane Complexes via Alkylalkoxyzirconocene
Authors: Takahashi Tamotsu , Aoyagi Koichiro , Hara Ryuichiro , Suzuki Noriyuki
Published: May 2006

Treatment of trans-3,4-diethylzirconacyclopentane complex, which was a selective butene-butene coupling product on zirconium, with methanol followed by bromine gave selectively monobromination product, 2-ethyl-3-methyl-1-bromopentane, in 89% yield with high stereoselectivity. Similarly, non-conjugated diene cyclization products on zirconium were also selectively converted into monohalogenated compounds. These selective monohalogenations proceeded via alkylalkoxyzirconocene complexes.
Synthesis of Cyclotetragermanes of the Type of [R(Ph)Ge]4 and Conversion to [R(Cl)Ge]4. The First Functionalized Cyclotetragermanes
Authors: Sekiguchi Akira , Yatabe Tetsuo , Naito Hiroyoshi , Kabuto Chizuko , Sakurai Hideki
Published: May 2006

Condensations of R(Ph)GeCl2 (R = t-Bu and R = CEt2Me) with Mg/MgBr2 in THF produced cyclotetragermanes [R(Ph)Ge]4, which were converted to [R(Cl)Ge]4 by treatment with HCl/AlCl3 or with CF3SO3H followed by CH3COCl. The crystal structure of [t-Bu(Cl)Ge]4 was established by X-ray diffraction. Unusual configurational behavior of cyclotetragermanes is also described.
C(9)-C Bonds of 10-Methyl-9-alkyl-9,10-dihydroacridines Acting Like Metal-Carbon Bonds in the Reactions with Electrophiles
Authors: Fukuzumi Shunichi , Tokuda Yoshihiro , Fujita Morifumi , Otera Junzo , Chanon Michel , Rajzmann Michel , Thomas Phillipe
Published: May 2006

The C(9)-C bonds of 10-methyl-9-alkyl-9,10-dihydroacridines (AcrHR : R = CMe2COOMe, CMe(H)COOEt, But, CHPh2) are readily cleaved by electrophiles (perchloric acid, oxygen, and iodine) in acetonitrile at 298 K, acting like metal-carbon bonds to yield the corresponding alkane, alkyl hydroperoxide, and alkyl iodide, respectively.
Photolysis and Photopolymerization of Novel Organic Peroxides Having a Benzophenone Chromophore
Authors: Suyama Shuji , Higuchi Yoshiki , Kumura Hiromi
Published: May 2006

Dialkyl peroxides having a benzophenone chromophore have been successfully synthesized from the reaction of 2-t-butyldioxy-2-methyl-1-propanol and corresponding benzoyl chloride. These peroxides had UV absorption above 300 nm. The free radicals produced during the photolysis of these compounds initiated the radical polymerization of methyl methacrylate at room temperature.
Facile Attachment of Uranium Hexacyanoferrate to Carbon Electrode by Reductive Electrodeposition
Authors: Jiang Mian , Wang Min , Zhou Xingyao
Published: May 2006

Cyclic voltammetric scan of the glassy carbon substrate in an acidic solution containing both uranyl salt and ferricyanide can result in the new surface-deposition of an inorganic redox active film–polynuclear uranium hexacyanoferrate.
Structure Elucidation of Oxygenated Sterols from Eggs of Sea Hare, Aplysia Juliana
Authors: Yamaguchi Yoshihiro , Nakanishi Yukio , Shimokawa Teruyuki , Hashiguchi Shigeru , Hayashi Akira
Published: May 2006

Cholest-7-en-6R-methoxy-3S,5R-diol, a new sterol, and cholest-7-en-3S,5R,6R-triol were isolated from eggs of sea hare, Aplysia Juliana, and their structures and absolute configurations deduced by spectroscopic studies and chemical synthesis.
Electrochemical Methane Activation to C2-Hydrocarbons Using Protonic Conductor
Authors: Hibino Takashi , Hamakawa Satoshi , Iwahara Hiroyasu
Published: May 2006

Coupling of methane was performed using SrCe0.95Yb0.05O3−x as a solid electrolyte. The electrochemical hydrogen pump activated methane to C2-hydrocarbons without forming carbon dioxide.
Three-Layer Organic Solar Cell
Authors: Shichiri Tokushige , Suezaki Minoru , Inoue Takeshi
Published: May 2006

Three-layer organic cells composed of perylene pigment/phthalocyanine/quinacridone were examined, and the photocurrent was founded to be greatly affected by the thickness of phthalocyanine layer. Furthermore, the tandem type solar cells were fabricated by combining of several units of the three-layer cell to clarify the relationship between the number of accumulated unit cells and cell characteristics.
Direct Determination for the pKa Values of Radical Cations of NADH Analogues
Authors: Fukuzumi Shunichi , Tokuda Yoshihiro
Published: May 2006

The pKa values of radical cations of NADH analogues, 10-methyl-9,10-dihydroacridine (AcrH2) and 9,10-dimethyldihydroacridine (AcrHMe), have been determined directly by measuring the decay of the transient absorption spectra of the radical cations, formed by the electron transfer oxidation with Fe3+, through the deprotonation in the presence of various concentrations of perchloric acid in acetonitrile at 298 K.
Hydrogenation of Alkyne Using Palladium-Zeolite Coupled with Diphenyldiethoxysilane
Authors: Kuno Hideyuki , Shibagaki Makoto , Takahashi Kyoko , Honda Ichiro , Matsushita Hajime
Published: May 2006

Palladium-zeolite coupled with diphenyldiethoxysilane was prepared by Chemical Vapor Deposition (CVD). The hydrogenation of alkyne was carried out over this catalyst. Alkyne was converted to the corresponding alkene with a high selectivity in a manner similar to that in the case of Lindlar catalyst.
Self-aggregates of Hydrophobized Polysaccharide as a Host for Macromolecular Guests
Authors: Akiyoshi Kazunari , Nagai Kenichi , Nishikawa Takehiro , Sunamoto Junzo
Published: May 2006

Nano-particles, which are self-aggregates of hydrophobized pullulan partly substituted cholesterol moieties (CHP), formed a complex with various globular and soluble proteins such as hemoglobin, peroxidase, myoglobin, and cytochrome c. The nano-particle also showed an excellent colloidal stability and almost no dissociation of the protein from the complex.
Molecular Recognition Using Cyanine-α-Helical Poly(L-Lysine) Complexes in Methanol
Authors: Ihara Hirotaka , Shibata Masaaki , Hirayama Chuichi
Published: May 2006

Cyanine dyes bound to α-helical poly(L-lysine·HBr) (PLL·HBr) in methanol provide extremely strong exciton couplings in CD spectra caused by their R-chiral dimer formation and that dyes-PLL complexes show varying degrees of remarkable strength change in the CD recognizing on their methylene numbers upon addition of α,ω-diaminoalkanes.
Antioxidant Activities of α-Tocopherol and Hydroxycarbazole against Lipid Peroxidation in Homogeneous Solution and in Liposomal Membranes
Authors: Iwatsuki Misato , Niki Etsuo , Kato Shinichiro , Nishikori Koji
Published: May 2006

α-Tocopherol and carazostatin (1-heptyl-3-hydroxy-2-methyl-carbazole) acted as a potent antioxidant against lipid peroxidation. α-Tocopherol was more active than carazostatin in homogeneous solution, whereas, in the liposomal membranes, carazostatin exhibited a stronger antioxidant activity than α-tocopherol. This novel finding on such a reversal in relative antioxidant activity by the change in reaction media suggests the importance of mobility of an antioxidant at microenvironment in determining antioxidant activity.
Regioselective Thermal Cyclization of N-Aryl-4-chloro-1-aza-1,3-butadiene Derivatives. A Short and Efficient Synthesis of Dibenz[c,h]acridines
Authors: Kar Gandhi Kumar , Sami Izhar , Ray Jayanta Kumar
Published: May 2006

Dibenz[c,h]acridines have been synthesised in good yields by thermal cyclization (140–180 °C) of N-aryl-4-chloro-1-aza-1,3-butadiene derivatives followed by dehydrogenation.
Crystal Engineering and Substituent Effect of Hindered Phenols for SHG Materials
Authors: Takagi Koichi , Mizuno Akira , Kubata Michiru , Mizoguchi Akira , Furushow Masaru , Matsuoka Masaru
Published: May 2006

2,6-Di-tert-butylphenol moiety was found to be effective to control molecular packing in crystals for SHG materials. Many derivatives having compact acceptor group at 4-position of hindered phenols showed SHG responses depending on the electron withdrawing effect of an acceptor. The X-ray structural analyses revealed that molecular packing was controlled both by the steric requirements and the intermolecular hydrogen bonding.
A New and Efficient Method for the Preparation of S-Phenyl Carbothioates via Mixed Anhydrides Using Active Titanium(IV) Salts
Authors: Mukaiyama Teruaki , Miyashita Mitsutomo , Shiina Isamu
Published: May 2006

In the presence of a catalytic amount of titanium(IV) salt, various S-phenyl carbothioates are prepared in excellent yields by the reaction of nearly equimolar amounts of silyl derivatives of carboxylic acids and benzenethiols with p-trifluoromethylbenzoic anhydride.
An Efficient Catalytic Friedel-Crafts Acylation Reaction of Equimolar Amounts of Aromatic Compounds and Free Carboxylic Acids or Their Trimethylsilylesters via Mixed Anhydrides
Authors: Mukaiyama Teruaki , Suzuki Kaoru
Published: May 2006

In the presence of an active catalyst generated from SiCl4 and AgClO4, the Friedel-Crafts acylation reaction between equimolar amounts of aromatic compounds and mixed anhydrides, formed in situ from free carboxylic acids (or their trimethylsilylesters) and p-trifluoromethylbenzoic anhydride, smoothly proceeds at room temperature to afford the corresponding aromatic ketones in high yields.
Stereoselective Synthesis of 2-Amino-2-deoxy-β-D-glucopyranosides and Galactopyranosides by Using a Catalytic Amount of Tin(II) Trifluoromethanesulfonate
Authors: Mukaiyama Teruaki , Matsubara Koki
Published: May 2006

In the presence of a catalytic amount of tin(II) trifluoromethanesulfonate, various 2-amino-2-deoxy-β-D-glucopyranosides or galactopyranosides are stereoselectively synthesized in good yields from 1,3,4,6-tetra-O-acetyl-2-deoxy-2-(2,2,2-trichloroethoxy carbonylamino)-β-D-glucopyranose or galactopyranose and alkyl trimethylsilyl ethers, respectively.
Approaches toward High-Spin Poly[m-(nitrenophenylene)ethynylenes]. Magnetic Interaction in the Oligomers Containing Two, Three, and Five Nitrene Units
Authors: Sasaki Shigeru , Iwamura Hiizu
Published: May 2006

Oligonitrenes representing the various unit structures in poly[m-(nitrenophenylene)ethynylenes] (1) were prepared and studied by means of EPR and magnetization measurements which support our hypothesis that 1 will have a superhigh-spin ground state.
Photoregulation of Tilt Angle of Nematic Liquid Crystals by Azobenzene Layers
Authors: Sakuragi Masako , Tamaki Takashi , Seki Takahiro , Suzuki Yasuzo , Kawanishi Yuji , Ichimura Kunihiro
Published: May 2006

Hybrid-type liquid crystal cells were prepared with glass plates modified with octadecyltrichlorosilane and Langmuir-Blodgett film of azobenzene polymer. The tilt angle of director of the nematic liquid crystals is continuously varied by regulating the fraction of trans-azobenzene units by irradiating light wavelength.
Preferential Exhibition of Smectic A Phase through Intramolecular Hydrogen Bonding in 2-Amino-5-phenyltropone Liquid Crystals
Authors: Mori Akira , Katahira Kouki , Kida Katsuhiko , Takeshita Hitoshi
Published: May 2006

Two new types of liquid crystals, 5-(4-alkanoylaminophenyl)-2-alkanoylaminotropones and 5-(4-alkanoylaminophenyl)-2-alkanoyloxytropones, were prepared. The former showed the smectic A phase and the latter did the smectic A and C phases. The 1H NMR spectra indicated the former to be in intramolecularly hydrogen-bonded L-shaped alignment.