bluuebunny/crossref_metadata_2025 huggingface dataset:
Second-Order Nonlinear Optical Langmuir-Blodgett Films Made of a Series of Ferrocenyl Lanthanoid Complexes
Authors: Gao Li-Hua , Wang Ke-Zhi , Huang Chun-Hui , Zhao Xin-Sheng , Xia Xiao-Hua , Xu Jing-Mei , Li Tian-Kai
Published: March 2006

A series of lanthanoid complexes (E)-1-ferrocenyl-2-(N-hexadecylpyridinium-4-yl)ethylene tetrakis(dibenzoylmethanato)lanthanoides(III) (La, Nd, Dy and Yb) have been newly synthesized for second-order nonlinear optical LB materials. The monolayer behaviors at the air-water interface, ultraviolet spectra and second-harmonic generation (SHG) of the films have been reported. The values of second-order molecular hyperpolarizability β of the complexes were estimated to be (1.37–1.58) × 10−28 esu.
Electrolytic Behavior of Iodo- and Chlorosilanes. The Formation of Si-Si and Si-sp-C Bonds
Authors: Kunai Atsutaka , Ohnishi Osamu , Sakurai Tomohiro , Ishikawa Mitsuo
Published: March 2006

Electrolysis of iodosilanes with Al/Pt electrodes in pivalonitrile results in the formation of the Si–Si bonds to give the corresponding disilanes. On the other hand, the electrolysis of various halosilanes such as iodo-, chloro-, and fluorosilanes with Pt/Pt electrodes in the presence of phenylacetylene leads to the formation of the Si–sp-carbon bonds to give phenylethynylated products.
Rate Acceleration of the Oxidation of an NADH Model by Flavin with a Functionalized Flavin Receptor in Chloroform
Authors: Kajiki Takeshi , Tamura Norio , Nabeshima Tatsuya , Yano Yumihiko
Published: March 2006

A melamine derivative bearing a guanidinium ion was found to enhance the oxidation-activity of flavin via hydrogen bonding at the N(1) position of the isoalloxazine ring for the oxidation of N-benzyl-1,4-dihydronicotinamide (BNAH) in CHCl3.
A New Organic Metal Based on the DHTTF (Dihydrotetrathiafulvalene) Derivative, (MDHT)2AuI2
Authors: Yamada Jun-ichi , Takasaki Satoshi , Kobayashi Mototada , Anzai Hiroyuki , Tajima Naoya , Tamura Masafumi , Nishio Yutaka , Kajita Koji
Published: March 2006

Electrochemical properties of various DHTTF derivatives and electrical conductivities of their radical cation salts have been investigated. Among their radical cation salts, the electrical resistance of (MDHT)2AuI2 [MDHT = methylenedithio(dihydro)tetrathiafulvalene] on a single crystal exhibited the metallic temperature dependence.
Chromatic Phase and Molecular Packings of Polydiacetylene Langmuir-Blodgett Films
Authors: Kuriyama Keisuke , Kikuchi Hirotsugu , Kajiyama Tisato
Published: March 2006

Molecular packings of polydiacetylene (PDA) Langmuir-Blodgett (LB) film in various chromatic phases such as blue, red and bluish-green forms have been clarified by the electron diffraction analysis for the first time. Spectroscopic properties - molecular packings relationships for the chromatic phases of PDA LB film indicate that the chromatic phase of PDA is strongly dependent on its molecular packing in the crystal phase.
Totally ab Initio Prediction of the Structures of CO2 Molecular Crystal
Authors: Hirano Tsuneo , Tsuzuki Seiji , Tanabe Kazutoshi , Tajima Nobuo
Published: March 2006

We have succeeded in predicting a molecular crystal structure from first principles. The potential parameters and geometry for CO2 molecule were determined by ab initio molecular orbital calculations. The experimentally observed CO2 crystal structures at low and high pressures have been reproduced by molecular dynamics method without any a priori assumptions on lattice constants nor space group symmetry. With extra pressure of 1 GPa in [010] direction, the structural change observed at about 10 GPa has also been reproduced.
Direct Electrochemistry of Blue Copper Proteins at Au Electrodes Modified with Promoters
Authors: Sakurai Takeshi , Nose Fumitaka
Published: March 2006

Cyclic voltammetry of six blue copper proteins, plastocyanin, azurin, umecyanin, plantacyanin, pseudoazurin, and stellacyanin was performed at Au electrodes modified with five promoters. A proper combination of non-covalent interactions such as hydrophobic interaction, hydrogen bonding, and electrostatic interaction realizes the access of the northern area of the protein molecules towards the electrode surface.
NMR of Hectorite Ion-exchanged by Trimethyltin and Dimethyltin Cations
Authors: Hayashi Shigenobu , Tanaka Atsushi , Soma Mitsuyuki
Published: March 2006

119Sn high resolution solid state NMR of hectorite ion-exchanged by trimethyltin (TMT) and dimethyltin (DMT) cations has shown that under dry atmosphere TMT loses coordinated water molecules to give an abnormally high chemical shift δ = 300.
Effect of the Oxidation State of the Sulfur Atom on the Exchange Interaction between Two Triplet Carbene Units through Diphenyl Sulfide p,p′-Diyl Couplers
Authors: Matsuda Kenji , Yamagata Takehiro , Iwamura Hiizu
Published: March 2006

The exchange interaction between two triplet carbene centers through diphenyl sulfide p,p′-diyl and the corresponding sulfoxide coupling units was studied. While the former was found to be a ferromagnetic coupler, the latter was found to be an antiferromagnetic coupler.
Formation and Reactions of the First Diarylgermanone Stable in Solution
Authors: Tokitoh Norihiro , Matsumoto Tsuyoshi , Okazaki Renji
Published: March 2006

Treatment of an overcrowded diarylgermylene bearing 2,4,6-tris[bis(trimethylsilyl)methyl]phenyl and 2,4,6-triisopropylphenyl groups with tribenzylamine N-oxide gave the corresponding diarylgermanone 4, the first example of a stable germanium-oxygen double-bond compound. Germanone 4 was stable in solution at room temperature for a short time and underwent [2+3]cycloaddition with mesitonitrile oxide, while in the absence of such a trapping reagent 4 gave two diastereomeric intramolecular cyclization products 8 and 9.
A New Access to Mori’s Intermediate for the Practical Synthesis of (−)-Periplanone-B
Authors: Hashimoto Shun-ichi , Miyazaki Yoji , Shiro Motoo , Ikegami Shiro
Published: March 2006

Mori’s key intermediate 2 for the large-scale synthesis (−)-periplanone-B has been prepared from β-keto prenyl ester 8 by exploiting the new three-step sequence of α-alkynylation with alkynyllead(IV) triacetate, semihydrogenation, and palladium-catalyzed deallyloxycarbonylation with HCO2HNEt3, and subsequent isomerization induced by NaOCH3.
Syntheses of Silver(I) Complexes with N,N′-Ethylene-Bridged-(S)-Histidyl-(S)-Histidine and -(S)-Methionyl-(S)-Methionine Derivatives
Authors: Kojima Yoshitane , Watanabe Masaaki , Miyake Hiroyuki
Published: March 2006

Silver(I) complexes of N,N′-ethylene-bridged-(S)-histidyl-(S)-histidine and -(S)-methionyl-(S)-methionine derivatives have been synthesized and characterized as monomeric complex ions coordinated only by two functional groups on the side chains of each ligand.
Structure and Activity of Fibronectin-related Peptides. The Role of Amino Acid Residues of Positions 5 and 6 in RGDSPASS-containing Cyclic Decapeptide (FR-1)
Authors: Yamamoto Yasuo , Almehdi Mirza , Katow Hideki , Sofuku Shosuke
Published: March 2006

Side chains’ repulsion between AA5 and AA6 in the cyclic decapeptide (FR-1) is important for binding to the fibrinogen receptor on the platelet surface. [Phe5]-FR-1 exhibited higher activity as a platelet aggregation inhibitor than FR-1.
Palladium-Catalyzed Cleavage of P-C Bonds in Quaternary Phosphonium Salts and Its Applications to Organic Synthesis
Authors: Sakamoto Masato , Shimizu Isao , Yamamoto Akio
Published: March 2006

Phosphonium salts, PPh4I and PMePh3I, oxdatively add to Pd(methyl acrylate)(PMePh2)2 to give trans-[PdPhI(PMePh2)2] in moderate yields with cleavage of the P-phenyl bond. Conversely thermolysis of trans-PdPhIL2 (L = PMePh2 and PPh3) reductively eliminates PMePh3I and PPh4I, respectively. Application of the P-C bond cleavage process in phosphonium salts to olefination, carbonylation and hydrogenation reactions has been explored.
Transannular Interactions in Fluorine-substituted [3.3]Metacyclophanes
Authors: Osada Satoshi , Miyahara Yuji , Shimizu Nobujiro , Inazu Takahiko
Published: March 2006

Effects of fluorine substituents on transannular interaction in [3.3]metacyclophanes were examined on the basis of chemical and spectral properties of five [3.3]metacyclophanes possessing one or two fluorine atoms at the inner and/or outer positions.
Na+/Li+ Exchange in One-Dimensional Tunnels of the Framework Structure
Authors: Michiue Yuichi , Takenouchi Satoshi , Sasaki Takayoshi , Watanabe Mamoru
Published: March 2006

Metastable Li-titanogallate has been obtained by substituting Li+ ions for Na+ ions of NaxTi2−xGa4+xO10 (x = 0.85) in molten LiNO3 at 450 °C. Na+ ions in one-dimensional tunnels of the framework structure have been practically exchanged by Li+ ions. Rietveld fitting of X-ray diffraction profile has clarified that the framework stucture has been retained but reasonably deformed by the ion exchange reaction.
Thermolysis of β-Siloxyalkylboranes: Formation of Alkenes and/or Silyl Enol Ethers
Authors: Kawashima Takayuki , Yamashita Naoko , Okazaki Renji
Published: March 2006

erythro-Trimethylsilyl ether 3a underwent stereospecific and quantitative syn-elimination of trimethylsiloxy(dimesityl)borane upon heating to give (Z)-β-methylstyrene like the corresponding hydroxy borane 1, whereas the thermolysis of t-butyldimethlsilyl ether 3c afforded mainly (Z)-silyl enol ether 6 by elimination of dimesitylborane. Triethylsilyl ether 3b gave a mixture of both products. These results indicate that two elimination reactions via a four-centered transition state proceed competitively depending on the steric bulkiness of the silyl group.
Asymmetric Simmons-Smith Cyclopropanation of E-Allylic Alcohols Using 1,1′-Bi-2-naphthol-3,3′-dicarboxamide as a Chiral Auxiliary
Authors: Kitajima Hiroshi , Aoki Yuko , Ito Katsuji , Katsuki Tsutomu
Published: March 2006

N,N,N′,N′-Tetraethyl-1,1′-bi-2-naphthol-3,3′-dicarboxamide (1b) was found to be an effective chiral auxiliary for asymmetric Simmons-Smith cyclopropanation and high enantioselectivity greater than 85% ee was achieved in the reaction of E-allylic alcohols.
Simple Separation of an Isomeric Mixture of Dihexylbithiophenes with Head-to-head and Head-to-tail Orientations
Authors: Higuchi Hiroyuki , Hayashi Noriyuki , Koyama Haruki , Ojima Juro
Published: March 2006

The isomeric mixture of 3,3′-dialkylbithiophenes with head-to-head (H-H) and head-to-tail (H-T) orientations was separated into each isomer by using preferential brominartion of the H-T isomer. This separation method proved to be useful for simultaneous preparation of the pure H-H and H-T bithiophenes which are inaccessable by other methods.
Photoactivation of Methane on Metal Ion-Supported Silica Gel
Authors: Ogata Atsushi , Matsuura Mitsunori , Obuchi Akira , Yagita Hiroshi , Mizuno Koichi
Published: March 2006

Photoactivation of methane has been investigated on metal ion-supported silica gels. Methyl radicals were detected on Na, Mg, Ca, Sr, Y, Ti, Zn, Zr, Sn, Pb and Bi/SiO2 at 77 K by electron spin resonance (ESR). It is found that methane was dissociated to the methyl radical on Na, Mg, Sr, Zn and Sn supported samples with lower photon energy than C–H bond dissociation energy in methane.
A New Entry to Difluoromethylene Compounds; An Electrochemical Method
Authors: Asai Hideki , Uneyama Kenji
Published: March 2006

Electroreduction of dibromodifluoromethane in the presence of diphenyldiselenide and olefins in a DMF-(Pt)-(Al) system provided adducts of in situ generated bromodifluoromethyl radical and phenylselenenyl group to olefins. One electron transfer from benzeneselenolate to CF2Br2 induces the formation of CF2Br· radical. This system is also useful for generation of ·CF2CO2Et radical from ethyl bromodifluoroacetate.
Structures and Conducting Properties of CPTM-TTP Salts
Authors: Misaki Yohji , Kawakami Kazuya , Fujiwara Hideki , Yamabe Tokio , Mori Takehiko , Mori Hatsumi , Tanaka Shoji
Published: March 2006

The title donor, CPTM-TTP (4,5-cyclopenteno-4′,5′-bis-(methylthio)-2,5-bis(1,3-dithiol-2-ylidene)-1,3,4,6-tetrathiapen-talene) has produced metallic cation radical salts with octahedral and linear anions. Among them, (CPTM-TTP)4AsF6 has a two-dimensional “β-type” arrangement of donor molecules and a closed Fermi surface.
Abnormal Dielectric Response of Aerosol OT W/O Microemulsion in Cyclohexane at 298.15 K
Authors: Tanaka Reiji , Okazaki Kaori , Tsuzuki Hideo
Published: March 2006

A dielectric constant for W/O microemulsions consisting of sodium bis (2-ethyhexyl) sulfosuccinate (AOT), water and cyclohexane was measured at 1 MHz and at 298.15 K. Minima were found in the dielectric constant when a molar ratio of water to AOT was 15 irrespectively of the AOT concentration. This minimum would be related to symmetric hydration of ions, therefore, water pool in the microemulsion becomes more nonpolar around the ratio of 15.
Precious Metal Loaded In/H-ZSM-5 for Low Concentration NO Reduction with Methane in the Presence of Water Vapor
Authors: Ogura Masaru , Hiromoto Sachiko , Kikuchi Eiichi
Published: March 2006

Catalytic activity of In/H-ZSM-5 for selective reduction of nitric oxide at a low concentration with methane was greatly improved by supporting precious metals (Pt, Rh, Ir), which promoted not only NO oxidation, but also enhanced NO2 adsorption in the presence of water vapor.
Synthesis of Natural Carotenoid-Modified Pyropheophorbide Dyads for Investigation of Carotenoid-Chlorophyll Excited State Interactions
Authors: Shinoda Satoshi , Osuka Atsuhiro , Nishimura Yoshinobu , Yamazaki Iwao
Published: March 2006

Two sets of new fucoxanthin or zeaxanthin-linked pyropheophorbides were prepared to compare the intramolecular excited-state interactions. Fucoxanthin acts as a better antenna toward pyropheophorbide by transferring singlet energy from its S1-state, while zeaxanthin is a poorer antenna and quenches the S1-state of the pyropheophorbide possibly by reverse energy transfer.
Self-assembled Dinuclear Platinum(II) Complexes with 6,6′-Bis(1-methylbenzimidazol-2-yl)-2,2′-bipyridine: Synthesis, X-Ray Structure, and Solution Behaviors
Authors: Haga Masa-aki , Hiratsuka Koji , Kato Masako , Kurosaki Hiromasa , Goto Masafumi , Arakawa Ryuichi , Yano Shigenobu
Published: March 2006

A novel self-assembly of two 6,6′-bis(1-methylbenzimidazol-2-yl)-2,2′-bipyridine (dmbbbpy) with two Pt(II) ions was characterized in both solid and solution states by X-ray structure analysis, 1H NMR and electrospray mass spectra.
Synthesis and Characterization of cis-[Cp*W(CO)2(MeCN)Me] and Its Stereospecific Substitution Reactions with Phosphines
Authors: Sakaba Hiroyuki , Ishida Kazushige , Horino Hiroshi
Published: March 2006

Photolysis of [Cp*W(CO)3Me] (Cp* = η5-C5Me5) in MeCN gave cis-[Cp*W(CO)2(MeCN)Me] in a high yield. Stereospecific substitution reactions of the acetonitrile complex with PR3 (R = Me, Ph) took place under mild conditions to produce cis-[Cp*W(CO)2(PR3)Me]. Reactions of M[Cp*W(CO)2(PR3)] (M = Li, R = Me; M = K, R = Ph) with MeI afforded trans-[Cp*W(CO)2(PR3)Me] as major products, which isomerized to the more stable cis isomers.
Synthesis and Properties of Deuterated Antiferroelectric Liquid Crystals
Authors: Kusumoto Tetsuo , Sato Ken-ichi , Kumaraswamy Gullapalli , Hiyama Tamejiro , Isozaki Tadaaki , Suzuki Yoshiichi
Published: March 2006

Optically active compounds containing a deuterated chiral alkyl ester group [(R)-ArCOOCD(CD3)CD2-n-C5H11, ArCOOCH(CD3)CD2-n-C5H11, ArCOOCD(CH3)-n-C6H13: Ar = n-C8H17OC6H4C6H4COOC6H4] were prepared from 2-octanone and were proved to exhibit liquid crystal phases (Cr 73 SmCA* 117 SmC* 122 SmA 149 Iso) same as the parent compound [(R)-ArCOOCH(CH3)-n-C6H13].
Polymerization-Induced Epitaxy. Highly Ordered Ultrathin Films of Poly(phenyloxazoline) on Graphite
Authors: Sandberg Mats , Sano Masahito , Yoshimura Susumu
Published: March 2006

Ultrathin films of poly(N-benzoylethyleneimine) were grown on the basal plane of graphite by the method of polymerization-induced epitaxy. Scanning tunneling microscopy of the thin films showed periodic structures which indicate formation of crystalline layers.
Octacarbonyldicobalt Promoted Transformation of 1-(1,2-Propadienyl)cyclopropanols to 1,4-Hydroquinones
Authors: Iwasawa Nobuharu , Owada Yufu , Matsuo Takeshi
Published: March 2006

A novel transformation reaction of 1-(1,2-propadienyl)cyclopropanols to 1,4-hydroquinone derivatives was developed utilizing the interaction of 1,2-propadienes and Co2(CO)8.
Directly Experimental Evidence for Melting Process of Solid Domains in Monolayers of Fatty Acids at the Air-water Interface by a Brewster Angle Microscope
Authors: Lu Zuhong , Nakahara Hiroo
Published: March 2006

First direct observation of the melting processes for fatty acid monolayer at the air-water interface has been successfully made by a Brewster angle microscope. The melting temperatures of solid domains in the monolayers of myristic, palmitic and stearic acids are around 6 °C, 28 °C and 46 °C, respectively. Both the domain size and their distribution become homogeneous when the molten monolayer is cooled down back to the temperature below melting points.
Fluorescent PET(Photoinduced Electron Transfer) Sensors for Calcium Ions. Extension to Multiple Fluorophores and Virtual Spacers
Authors: Silva A Prasanna de , Gunaratne H Q Nimal , Kane Áine T M , Maguire Glenn E M
Published: March 2006

New bifluorophoric sensors QCa3 and QCa4 show larger Ca2+-induced fluorescence enhancements and (for QCa4 only) lower Ca2+ binding constants than their monofluorophoric counterparts due to statistics and remote steric effects respectively. The PET sensor principle is extended to twisted biaryl systems which can give rise to twisted internal charge transfer (TICT) excited states by the re-examination of Tsien’s rhod-2.
Regio- and Stereo-Controlled Alkoxyiodination of 1,3-Diene Using Iodine-Cerium(IV) Ammonium Nitrate
Authors: Horiuchi C Akira , Hosokawa Haruomi , Kanamori Miyuki , Muramatsu Yukiko , Ochiai Keiko , Takahashi Eiji
Published: March 2006

Reaction of 1,3-cycloalkadienes (cyclopentadiene, cyclohexadiene, and cycloheptadiene) with iodine-cerium(IV) ammonium nitrate in alcohols, gave the corresponding regiospecific trans-2-alkoxy-1-iodo compounds as major products accompanied with 1,4-dialkoxy compounds as by-products. In the case of CH3CN-H2O as solvent, trans-iodohydrins were obtained. Thus the reaction of cyclic and acyclic 1,3-diene derivatives using this synthetic method afforded the 1,2-addition alkoxyiodo compounds preferentially.
New Liquid-Crystal Polymer with a 1,3-Dithiane Ring
Authors: Haramoto Yuichiro , Ujiie Seiji , Nanasawa Masato
Published: March 2006

New polymerizable liquid crystal materials, 10-{4-[5-(4′-ethoxyphenyl)-1,3-dithian-2-yl]phenoxy}decyl methacrylate (5) and 10-{4-[5-octyl-1,3-dithian-2-yl]phenoxy}decyl methacrylate (7) have been synthesized and converted into polymers. Since these polymers (5′,7′) show the schlieren texture of a nematic phase (e.g. 5′ : G 5 N 63 I), they are a new type of liquid crystal polymer having a 1,3-dithiane ring in their mesogen units.
New Supported [Ru6N] Clusters as a Potential Transition Metal Nitride Catalyst
Authors: Izumi Yasuo , Aika Ken-ichi
Published: March 2006

Nitrido-ruthenium cluster [Ru6N] catalysts were prepared by reacting [Ru6N(CO)16]− cluster with MgO, K+-doped MgO or Cs+-doped MgO as a potential ruthenium nitride catalyst. The [Ru6N] unit remained in reaction conditions, and exhibited higher activities in ammonia synthesis than conventional Ru catalysts or Ru clusters prepared from [Ru6C(CO)16Me]− or [Ru6(CO)18]2−.
Molecular Fluorescence Sensor for Saccharides Based on Amino Coumarin
Authors: Sandanayake K R A Samankumara , Imazu Sachiko , James Tony D. , Mikami Masafumi , Shinkai Seiji
Published: March 2006

The intramolecular neighboring group participation of the amino group of 7-aminocoumarin moiety to phenylboronic acid gave fluorescence intensity and spectral changes upon saccharide binding which could be used in fluorescence mapping of saccharides in biological cells.
An Efficient Esterification Reaction between Equimolar Amounts of Free Carboxylic Acids and Alcohols by the Combined Use of Octamethylcyclotetrasiloxane and a Catalytic Amount of Titanium(IV) Chloride Tris(trifluoromethanesulfonate)
Authors: Izumi Jun , Shiina Isamu , Mukaiyama Teruaki
Published: March 2006

Various carboxylic esters are prepared in good to high yields from equimolar amounts of free carboxylic acids and alcohols by the combined use of octamethylcyclotetrasiloxane and a catalytic amount of TiCl(OTf)3.
Decomposition Degree of Chlorofluorocarbon and Hydrochlorofluorocarbon
Authors: Tanada Seiki , Kawasaki Naohito , Nakamura Takeo , Abe Ikuo
Published: March 2006

Hydrochlorofluorocarbons (HCFCs), which have a smaller ozone depleting propensity than the chlorofluorocarbons (CFCs) replacements, have been developed and produced. However, HCFCs decompose more readily than CFCs. Studying their decomposition degree is useful for increasing their recovery efficiency and minimizing their environmental impact. It is concluded that the amount of produced heavy metal ions was caused by a variation in the pH due to the HF and HCl, and the recovery of HCFC141b is more difficult than CFC113 or HCFC123.
Synthetic Applications of Bis(trimethylsilyl)sulfide: Part II. Synthesis of Aromatic and Heteroaromatic o-Azido-Thioaldehydes
Authors: Capperucci Antonella , Degl’Innocenti Alessandro , Scafato Patrizia , Spagnolo Piero
Published: March 2006

Treatment of aromatic and heteroaromatic o-azidoaldehydes with bis(trimethyl-silyl)sulfide and a suitable catalyst affords an easy access to the corresponding o-azidothioaldehydes as their Diels-Alder cycloadducts with dienes.
Synthesis and Mesogenic Properties of New Non-Sigmatropic, Monocyclic Troponoids, 5-Acyloxy-2-alkoxytropones
Authors: Mori Akira , Takematsu Shinji , Isobe Masahiro , Takeshita Hitoshi
Published: March 2006

A series of newly-prepared non-sigmatropic 5-acyloxy-2-alkoxytropones showed virtual SA-C transition temperatures as determined by extrapolation of the binary phase diagram. This is an example of the genuine monocyclic liquid crystals.
Microporous Heteropoly Compound as a Shape Selective Catalyst : Cs2.2H0.8PW12O40
Authors: Okuhara Toshio , Nishimura Toru , Misono Makoto
Published: March 2006

The pore size of acidic Cs salts (CsxH3−xPW12O40) was precisely controlled by the Cs content. Cs2.2H0.8PW12O40 possesses micropores in the range from 6.2 to 7.5 Å (in diameter) and exhibits efficient shape selective catalysis toward decomposition of ester, dehydration of alcohol, and alkylation of aromatics in liquid-solid system. This is the first example of shape-selective solid superacid.
Practical and Selective Method for Preparation of Cp2HfRCl and Cp2HfRR′
Authors: Takahashi Tamotsu , Nishihara Yasushi , Ishida Toyohisa
Published: March 2006

Practical method for preparation of Cp2HfRCl and Cp2HfRR′ has been investigated. Mono(alkyl)hafnocene chloride complexes were selectively prepared by the following methods; (i) a reaction of Cp2HfR(OMe) with MeCOCl and (ii) a reaction of Cp2HfCl2 with an excess of R3Al. Treatment of Cp2HfRCl with R′3Al led to an alkyl exchange reaction to form Cp2HfR′Cl. Mono(alkyl)hafnocene complexes prepared by (ii) reacted with one equiv of R′Li to give Cp2HfRR′ (R ≠ R′) with a high selectivity.
Mass Transport on a Clay-modified Electrode as Studied by Quartz Crystal Microbalance Method
Authors: Yao Ken , Shimazu Katsuaki , Yamagishi Akihiko
Published: March 2006

The quartz crystal microbalance method was applied to examine mass transport processes in the redox reactions of [Ru(bpy)3]2+ / [Ru(bpy)3]3+ (bpy = 2,2′-bipyridyl) in a clay modified electrode, and it was concluded that the oxidation of three [Ru(bpy)3]2+ molecules in a clay film was accompanied with the elimination of one [Ru(bpy)3]3+ molecule.
The First Synthesis of 1-Fluoro- and 1,3-Difluoroazulenes
Authors: Ueno Tetsuya , Toda Haruhiko , Yasunami Masafumi , Yoshifuji Masaaki
Published: March 2006

1-Fluoro- and 1,3-difluoroazulenes were synthesized by the reaction of azulene with N-fluoropyridinium salts in acetonitrile. Methyl azulene-1-carboxylates were also fluorinated to give the corresponding 3-fluoro derivatives. On the basis of the UV-visible absorption spectra, the fluorine atom acts as an electron-donating group to the azulene π-system due to the +Iπ effect.
Hydrogen Peroxide as a Dynamic Trigger for Phytoalexin Production
Authors: Murai Akio , Yoshizawa Yuko , Toida Tetsuya , Sakamoto Makoto , Monden Tsutomu , Masamune Tadashi
Published: March 2006

Potato tuber tissues, when infected with Phytophthora infestans or treated with arachidonic acid, generated H2O2 which then elicited accumulation of the phytoalexins. The plant tissues, when treated with H2O2, induced phytoalexin production, indicating that H2O2 is a dynamic substance for triggering the phytoalexin production in potato.
Monolayer Assemblies of Long-chain Complex Containing Rare-earth Metal : N,N-Distearyl-dimethylammonium Tetra (4,4,4-trifluoro-1-(2-thienyl)-1,3-butanediono) Europate(III)
Authors: Qian Dongjin , Nakahara Hiroo , Fukuda Kiyoshige , Yang Kongzhang
Published: March 2006

Monolayers of a newly synthesized long-chain complex of europium(III) and its mixtures with octadecane or arachidic acid were investigated. Using the conventional LB and horizontal methods, the mixed monolayers could be deposited on solid supports. For the complex in monolayer assemblies, the emission probabilities from higher excited state 5D1 than 5D0 were remarkably enhanced in comparison with those in the solution or crystalline.
Reversing-pulse Electric Birefringence of β-FeOOH Particles Dispersed in Aqueous Media
Authors: Peikov Viktor , Sasai Ryo , Yamaoka Kiwamu
Published: March 2006

The electric properties of colloidal β-FeOOH particles were investigated at a low particle concentration and at various ionic strengths by reversing-pulse electric birefringence. A dip in the electric birefringence signal was observed upon pulse reversal. The electric field orientation of the particles is due mostly to ion-fluctuation dipole moment parallel to the symmetric axis of the prolate ellipsoid.
A Novel Approach to the Synthesis of Taxol. A Synthesis of Optically Active 3,7-dibenzyloxy-4,8-di-t-butyl-dimethylsiloxy-5,5-dimethyl-6-p-methoxybenzyloxy-2-octanone by Way of Stereoselective Aldol Reactions
Authors: Mukaiyama Teruaki , Shiina Isamu , Sakata Kaku , Emura Takayuki , Seto Keitarou , Saitoh Masahiro
Published: March 2006

Optically active 3,7-dibenzyloxy-4,8-di-t-butyldimethylsiloxy-5,5-dimethyl-6-p-methoxybenzyloxy-2-octanone (2) has been synthesized by way of diastereoselective aldol reaction between 4-benzyloxy-5-t-butyldimethylsiloxy-2,2-dimethyl-3-p-methoxy-benzyloxypentanal (3) and ketene silyl acetal 4 using MgBr2·OEt2 as a catalyst. The chiral pentanal 3 was synthesized either by asymmetric aldol reaction of both prochiral aldehyde 5 and ketene silyl acetal 4 using a chiral Lewis acid or by diastereoselective aldol reaction between the chiral aldehyde 6 derived from l-serine and the lithium enolate derived from methyl isobutyrate.
Syntheses and Properties of Halogenated EDT-TTF Derivatives
Authors: Kux Ulrich , Suzuki Hironori , Sasaki Shigeru , Iyoda Masahiko
Published: March 2006

Chlorination and bromination of EDT-TTF produced mainly the dihalogenated products (EDT-TTFCl2 and EDT-TTFBr2) with small amounts of the monohalogenated derivatives. In contrast, iodination of EDT-TTF afforded the monoiodinated derivative as the major product, together with the diiodinated compound. The molecular structures of EDT-TTFCl2 and EDT-TTFBr2 have been determined, and the conductivities of CT-complexes and radical salts of new donors reported here have been measured.
Selective Killing of a Single Cancerous T24 Cell with TiO2 Semiconducting Microelectrode under Irradiation
Authors: Sakai Hideki , Baba Ryo , Hashimoto Kazuhito , Kubota Yoshinobu , Fujishima Akira
Published: March 2006

A titanium dioxide (TiO2) microelectrode has been applied for selective photo-killing of a single cancerous T24 cell. The anodically polarized TiO2 microelectrode effectively inactivated the T24 cell while in contact and under UV light irradiation; however, the cell was not killed when the microelectrode was located 10 μm away from the cell surface. Based on these results we concluded that the photogenerated holes and/or active oxygen species with short diffusion length are responsible for the cell death process.
Preparation of Perovskite-type LaFe0.5Co0.5O3 by Thermal Decomposition of Heteronuclear Complex, {La[Fe0.5Co0.5(CN)6]·4H2O}X
Authors: Traversa Enrico , Nunziante Patrizia , Sakamoto Masatomi , Watanabe Kazuaki , Sadaoka Yoshihiko , Sakai Yoshiro
Published: March 2006

Submicron perovskite-type LaFe0.5Co0.5O3 powders were prepared by the thermal decomposition of a title cyanide-bridged heteronuclear complex. The decomposition of CN bridge begins at about 360 °C and the formation of perovskite-type oxide proceeds at a higher temperature with a gradual decomposition of carbonates. Perovskite-type LaFe0.5Co0.5O3 with cubic structure was formed when the complex was calcined at 700 °C. By raising the calcining temperature to 900 °C, hexagonal phase was formed.
Synthesis and Relative Configuration of the Sugar Part of a Marine Toxin Polycavernoside-A
Authors: Fujiwara Kenshu , Amano Seiji , Murai Akio
Published: March 2006

Construction of the sugar part of polycavernoside-A, which has been isolated as one of toxic principles from the red alga Polycavernosa tsudai, is described starting from l-fucose and d-xylose in order to elucidate the relative stereochemistry.
New Access to Prostanoids Like from Easy Avaliable Starting Materials
Authors: Brosse Nicolas , Jamart-Grégoire Brigitte , Caubère Paul
Published: March 2006

Methylene cyclobutanols resulting from one step elimination-additions were transformed into new prostanoid-like derivatives with potential biological activity.
Induced Smectic Phase Formed by New Liquid Crystalline Binary Systems Consisting of Main Chain Polymer and Twin Compound
Authors: Ujiie Seiji , Uchino Hiroko , Iimura Kazuyoshi
Published: March 2006

The thermal and mesomorphic properties of the new liquid crystalline binary systems, consisting of a nematic main chain liquid crystalline polymer and a nematic twin liquid crystal, have been studied. The liquid crystalline binary systems formed an induced smectic A phase, which was characterized by a uniaxial conoscopic figure, a fan texture, and a broad X-ray scattering peak at the wide angle.
3,4,5-Tris(2,4-di-t-butyl-6-methoxyphenyl)-3,4,5-triselenoxo-1,2-diselena-3,4,5-triphospholane as a Selenation Reagent
Authors: An De-Lie , Toyota Kozo , Yasunami Masafumi , Yoshifuji Masaaki
Published: March 2006

A new type of phosphorus-selenium containing heterocyclic compound, 3,4,5-tris(2,4-di-t-butyl-6-methoxyphenyl)-3,4,5-triselenoxo-1,2-diselena-3,4,5-triphospholane, was prepared and was allowed to react with amides to give the corresponding selenoamides in good yields.
Structure of Cyclic Hexa-Pseudopeptide Constructed from N,N′-Ethylene-Bridged-(S)-Alanyl-(S)-Alanine and Glycine
Authors: Kojima Yoshitane , Yamashita Tetsushi , Miyake Hiroyuki
Published: March 2006

The crystal structure of an 18-membered cyclic pseudopeptide containing N,N′-ethylene-bridged-(S)-alanyl-(S)-alanine and glycine was determined by X-ray diffraction analysis. Moreover, the structure of this pseudopeptide was examined by 1H NMR measurement in CD3CN, and by molecular mechanics calculations.
Decomposition of Chlorofluorocarbon CFC-113 in Water by Ultrasonic Irradiation
Authors: Nagata Yoshio , Hirai Kyozo , Okitsu Kenji , Dohmaru Takaaki , Maeda Yasuaki
Published: March 2006

Chlorofluorocarbon CFC-113 was readily decomposed by ultrasonic irradiation in water with high efficiency to inorganics, such as CO, CO2, HCl, and HF.
Pt Catalyst Supported on Zeolite for Selective Oxidation of CO in Reformed Gases
Authors: Watanabe Masahiro , Uchida Hiroyuki , Igarashi Hiroshi , Suzuki Miki
Published: March 2006

A new catalyst for the oxidative elimination of CO from the mixed gas with large excess H2, in application to polymer electrolyte fuel cells, was developed. The catalyst consists of Pt nanocrystallites highly dispersed on A-zeolite. The catalyst is shown to exhibit a very high selectivity, for example, 10 times larger than Pt supported on alumina, under similar conversion levels. The possibility of achieving CO rejection to very small amounts is demonstrated with the proposed catalyst.
Cyclization of Ethyne and Propyne over Lanthanide Catalysts Deposited from Eu or Yb Metal Solutions in Liquid Ammonia
Authors: Imamura Hayao , Suda Eisaku , Konishi Tomohiro , Sakata Yoshihisa , Tsuchiya Susumu
Published: March 2006

Europium and ytterbium catalysts separated on active carbon from a solution of lanthanide metals dissolved in liquid ammonia were found to be effective for oligomerization of alkynes. Selective cyclic dimerization and trimerization of propyne and ethyne to cyclohexadiene and benzene occurred during the oligomerization, respectively, in which the active catalysts were characterized as lanthanide imides induced by the thermal treatment.
Novel Ladder Polymers by the Platinum Complex-Catalyzed Dehydrogenative Double Silylation Reaction of 1,2,4,5-Tetrakis(dimethylsilyl)benzene with Cyclic Diynes
Authors: Shimada Shigeru , Uchimaru Yuko , Tanaka Masato
Published: March 2006

A platinum complex-catalyzed dehydrogenative double silylation reaction of 1,2,4,5-tetrakis(dimethylsilyl)benzene with cyclic diynes gave ladder polymers quantitatively.
CIDNP Studies on the Photochemical Reaction of 4-Methyl-2-quinolinecarbonitrile with Optically Active (S)- or (R)-2-Phenylpropionic Acid. No Evidence for the Chiral Symmetry Breaking
Authors: Ali Sameh Saad , Maeda Kiminori , Azumi Tohru
Published: March 2006

The photochemical reactions of 4-methyl-2-quinolinecarbonitrile (MQCN) with the enantiomers of 2-phenylpropionic acid (PPA) has been studied by CIDNP technique. The problem of chemical behavior discrimination of the enantiomers of PPA proposed by Hata1 was examined. In contrast to the proposal of Hata, both (R) and (S) forms of PPA are shown to have radical intermediates in their reaction with MQCN.
Synthesis of AB Ring Model System of Taxol via Allylation of 8-Membered Ring Compound and Intramolecular Aldol Condensation
Authors: Mukaiyama Teruaki , Shiina Isamu , Kimura Kaname , Akiyama Yuji , Iwadare Hayato
Published: March 2006

1-t-Butyldimethylsiloxy-8,11,11-trimethylbicyclo[5.3.1]undec-7-en-9-one (2) has been synthesized via intramolecular aldol condensation of the precursor 3 by combined use of lithium diisopropylamide (LDA) and CeCl3. The dicarbonyl compound 3 was prepared by allylation of 8-membered ring ketone 6b.
C–H Bond Activation of the Ferrocenyl Group in the Reaction of σ-Ferrocenylplatinum Complex with Dimethyl or Diethyl Acetylenedicarboxylate
Authors: Onitsuka Kiyotaka , Yoshida Toshiya , Adachi Tomohiro , Yoshida Toshikatsu , Sonogashira Kenkichi
Published: March 2006

The treatment of σ-ferrocenylplatinum complex with dimethyl or diethyl acetylenedicarboxylate results in the formal insertion of acetylene into the C-H bond at the 2-position of the ferrocenyl group to yield a racemic mixture of σ-(2-ethenyl)ferrocenylplatinum complex (2). Characterization of complex 2 was performed by spectroscopic and X-ray diffraction analyses.
Immobilization of Protein on Micropatterns by the Use of Photoremovable Activated Ester
Authors: Ichinose Nobuyuki , Shimo Nobuo , Masuhara Hiroshi
Published: March 2006

3-Nitrophenoxycarbonyl group was introduced to a silylated glass surface with 3-mercaptopropyltrimethoxysilane (MPS) through the Michael addition of corresponding acrylic acid ester to the mercapto group of the MPS. The nature of this ester group, reactivity to amino group giving amide bond (activated ester) under dark and to water giving a corresponding carboxylic acid upon UV-irradiation, was utilized to prepare micropatterns of protein on the glass surface.
Direct Observation of Edge Dislocation in Lignoceric Acid Monolayer Based on Atomic Force Microscopy
Authors: Kajiyama Tisato , Oishi Yushi , Suehiro Kazuaki , Hirose Fuminobu , Kuri Taishi
Published: March 2006

Structural defect in lignoceric acid monolayer was investigated with an atomic force microscope(AFM). A molecular-resolution AFM image exhibited us the first direct observation of edge dislocation in the lignoceric acid monolayer.
Bromoalkoxy Addition on N-Azolyl Olefins
Authors: Beugelmans René , Lechevallier André , Gharbaoui Tawfik , Frinault Thierry , Benhida Rachid
Published: March 2006

N-Azolyl olefins undergo a cohalogenation reaction when treated by the NBS/ROH system to give novel N-(bromoalkoxypropane) azolyl derivatives.
In situ Fluorescence Observation of the Vacuum Deposition Process of Cyanooctyloxybiphenyl. Fluorescence Behavior Related to Structural Transformation during Deposition
Authors: Watanabe Keizo , Orihashi Yuji , Miyasaka Hiroshi , Itaya Akira
Published: March 2006

Fluorescence spectra of 4-cyano-4′-n-octyloxybiphenyl were measured during vacuum deposition on various substracts. A discontinuous change was found in the series of the fluorescence spectra observed during deposition. The change was ascribed to structural transformation from an amorphous state to a crystalline one. The average film thickness where the deposited film showed the transformation depended upon the property of substrate surfaces. These phenomena were discussed in terms of interactions between the substrate and the compound.
Generation of Acyl Radical Equivalents by Cathodic Reduction of Acyl Tributylphosphonium Ions
Authors: Maeda Hatsuo , Maki Toshihide , Ohmori Hidenobu
Published: March 2006

The species generated by one-electron transfer to acyl tributylphosphonium ions has proved to be potent acyl radical equivalents by the results that unsubstituted end 6-phenyl-substituted 5-hexenoic acids were transformed into cyclopentanones by the electrolysis in the presence of Bu3P in an undivided cell, although the yields were not satisfactory due to the formation of 5-hexen-1-als via further one-electron reduction of the radicals before their cyclization.
Catalytic Formation of Ketones via Double Alkylation of Carbon Monoxide Resulting from Reductive Disproportionation of Carbon Dioxide by [Ru(bpy)2(qu)(CO)]2+ (bpy = 2,2′-bipyridine, qu = quinoline)
Authors: Nakajima Hiroshi , Mizukawa Tetsuro , Nagao Hirotaka , Tanaka Koji
Published: March 2006

The title complex catalyzes reductive disproportionation of CO2 to afford CO and CO32− in the electrochemical CO2 reduction in the presence of LiBF4, while the same reduction in the presence of (CH3)4NBF4 in DMSO/CH3CN produced CH3COCH3, CH3COCH2COO−, and HCOO− as well as CO and CO32−.
Effects of Additives in the Reduction Using Bakers’ Yeast Cell-Free Extract
Authors: Ishihara Kohji , Higashi Yuji , Tsuboi Sadao , Utaka Masanori
Published: March 2006

By addition of diisopropyl fluorophosphate the undesirable hydrolysis of α-acetoxy ketones or alcohols was completely inhibited in the asymmetric reduction using bakers’ yeast cell-free extract, but hardly inhibited in the reduction using the whole cell suspension. The control of stereoselectivity by addition of metal chlorides was also conducted more effectively in the cell-free extract.
Electrocatalytic Four-Electron Reduction of Dioxygen by 1,2-Phenylene-Bridged Dicobalt Diporphyrins
Authors: Park Gil Jae , Nakajima Satoshi , Osuka Atsuhiro , Kim Kimoon
Published: March 2006

1,2-Phenylene-bridged dicobalt diporphyrin 1 catalyzes efficiently the four-electron reduction of dioxygen to water in acidic solution. The catalytic activity of the diporphyrin is strongly affected by the substituents on the phenyl rings attached to the porphyrin macrocycles.
Electrochemical Synthesis and Crystal Structure of a Novel One-Dimensional Halogen-Bridged Nickel(III) Complex
Authors: Ozawa Yoshiki , Toriumi Koshiro
Published: March 2006

A novel halogen-bridged one-dimensional NiIII–X–NiIII compound, {[NiIII(en)2Cl]Cl2}∞ (en = C2H8N2) has been synthesized by electrochemical oxidation. Single crystal X-ray crystallography revealed that a bridging halogen ion is located on the midpoint between two Ni(III) atoms with Ni–Cl 2.438 (1) Å. This is the first example for electrocrystallization of halogen-bridged 1-D metal complexes.
Alkylidenation of Ketones by gem-Dibromoalkane, SmI2, and Sm in the Presence of Catalytic Amount of CrCl3
Authors: Matsubara Seijiro , Horiuchi Miyuki , Takai Kazuhiko , Utimoto Kiitiro
Published: March 2006

Alkylidenation of ketones can be performed by the reaction with geminal dibromoalkane-SmI2-Sm in the presence of catalytic amount of CrCl3 at room temperature yielding the alkylidenated products in good to excellent yields.
Synthesis and Photophysical Property of Porphyrin-Linked Fullerene
Authors: Imahori Hiroshi , Hagiwara Kiyoshi , Akiyama Tsuyoshi , Taniguchi Seiji , Okada Tadashi , Sakata Yoshiteru
Published: March 2006

Porphyrin-linked fullerenes were prepared by the Diels-Alder reaction of bisbromomethylbenzene derivative to C60. The absorption spectra and electrochemical measurements indicate that there is little interaction between the porphyrin and the C60 moieties. Intramolecular electron transfer from the excited singlet state of zincporphyrin to C60 was observed by picosecond transient absorption measurements.
Trinuclear Cobalt(III) Complexes Containing Partial Cubane Co3O4 Core. Synthesis and Structure of [Co3(L)3(μ-OH)3(μ3-O)]Cl (L = ethylenediamine-N-acetate)
Authors: Ama Tomoharu , Miyazaki Jun-ichi , Hamada Kayo , Okamoto Ken-ichi , Yonemura Toshiaki , Kawaguchi Hiroshi , Yasui Takaji
Published: March 2006

Three isomers of [Co3(edma)3(μ-OH)3(μ3-O)]+ (edma: ethylenediamine-N-acetate) containing a partial cubane Co3O4 core were prepared and the structure of one of the isomers was determined by the X-ray diffraction method. These isomers are stable at least for 5 days in their neutral aqueous solutions.
Synthesis of Higher-Nuclearity Clusters by Use of Small Cluster Units as Building Blocks: Synthesis and X-Ray Structure Analysis of [ClCCo3(CO)8]2(μ-dppe) and [ClCCo3(CO)7][ClCCo3(CO)8](μ-TRIPHOS) (dppe = 1,2-bis(diphenylphosphino)ethane; TRIPHOS = bis(2-diphenylphosphinoethyl)phenylphosphine)
Authors: Onaka Satoru , Otsuka Mayumi
Published: March 2006

Two ClCCo3(CO)9 units are, after treatment with Me3NO, linked at basal cobalt atoms by dppe spacer to yield [ClCCo3(CO)8]2(μ-dppe) and by TRIPHOS to yield [ClCCo3(CO)7][ClCCo3(CO)8](μ-TRIPHOS); they are characterized by single crystal X-ray molecular structure analysis and two Cl atoms in the TRIPHOS derivative are found to be located in close proximity.
A Novel Conversion of 3,7-Disubstituted 2H,6H-Tetrahydro-1,5,3,7-diselenadiazocines to 4-Substituted 1,2,4-Diselenazolidines by Treating with Oxidizing Agents
Authors: Takikawa Yuji , Koyama Yutaka , Yoshida Takamasa , Shimada Kazuaki , Kabuto Chizuko
Published: March 2006

Oxidation of 3,7-disubstituted 2H,6H-tetrahydro-1,5,3,7-diselenadiazocines afforded 4-substituted 1,2,4-diselenazolidines in modest yields. The intermediates of the reactions were supposed to be diselena dications possessing 1,5,3,7-diselenadiazabicyclo[3.3.0]octane skeleton generated transiently by the transannular interaction of two selenium atoms.
Stereoselective Allylation of β-Hydroxy- and β-Amino-α,β-enones with Allyltrifluorosilane/Triethylamine Systems
Authors: Kira Mitsuo , Sato Kazuhiko , Sekimoto Kazushi , Gewald Rainer , Sakurai Hideki
Published: March 2006

Reactions of allyltrifluorosilanes with β-functional-α,β-enones such as o-hydroxy- and o-aminophenyl ketones and 1,3-diketones in the presence of triethylamine yielded the corresponding tertiary homoallyl alcohols in regiospecific and highly diastereoselective manner.
Effect of Pressure on Low Temperature Gasification of Wet Cellulose into Methane Using Reduced Nickel Catalyst and Sodium Carbonate
Authors: Minowa Tomoaki , Ogi Tomoko , Yokoyama Shin-ya
Published: March 2006

A water slurry of cellulose was directly gasified to methane using a reduced nickel catalyst and sodium carbonate at 400 °C under pressure (9-28 MPa) for 1 h. Methane yield depended on operating pressure and the highest yield was 190 mg per 1 g cellulose at around 15 MPa This value was 1.5 times that in the literature.
New Reaction Mode of the Dieckmann-Type Cyclization under the Lewis Acid-Et3N Conditions
Authors: Tamai Satoshi , Ushirogochi Hideki , Sano Shigeki , Nagao Yoshimitsu
Published: March 2006

Dieckmann-type cyclization reactions of various dicarboxylic acid derivatives were readily promoted by employing Lewis acids such as AlCl3, MgBr2, MgCl2, and Sn(OSO2CF3)2 in the presence of Et3N or N-ethylpiperidine. The cyclization reactions of half thiol diesters under the AlCl3-Et3N conditions exhibited different chemoselectivity from the cyclization under the basic conditions.
Synthesis of a Rigid Diacylglycerol Analogue Having a Bis-γ-butyrolactone Skeleton Separated by a Cyclopentane Ring
Authors: Lee Jeewoo , Barchi Joseph J , Marquez Victor E
Published: March 2006

A very efficient method for the construction of a new bis-γ-lactone system constructed on a cyclopenta[1,2-c:3,4-c′]perhydrodifuran scaffold was developed from cyclopentadiene and methyl (S)-(Z)-4,5-O-isopropylidenepent-2-enoate.
Photoreaction via Non-Resonant Two-Photon Excitation. Selective Silylene Extrusion from 2,2-Diphenyltrisilane
Authors: Kira Mitsuo , Miyazawa Takashi , Koshihara Shin-ya , Segawa Yusaburo , Sakurai Hideki
Published: March 2006

Non-resonant two-photon excitation of 2,2-diphenylhexamethyltrisilane with a 532 nm pulsed laser light induced the two major reactions, silylene extrusion and migration of the β-trimethylsilyl group with a quite different selectivity from that for the single-photon excitation.
The Stereochemical Outcome of the DAST Fluorination of 4′-Thiopyrimidine Nucleosides with “Up” Hydroxyl Groups is Controlled by the Oxidation State of the Sulfur Atom
Authors: Jeong Lak S , Marquez Victor E
Published: March 2006

DAST fluorination of 1-(5-O-trityl-3-deoxy-4-thio-β-d-threo-pentofuranosyl)uracil proceeds with retention of configuration, while the corresponding sulfoxide gives mainly the inverted product. The sulfone proceeds with elimination.
The Rapid Synthesis of High Purity [18F]Butyrophenone Neuroleptics from Nitro Precursors for PET Study
Authors: Hashizume Kazunari , Hashimoto Naoto , Kato Hiroo , Cork David G , Miyake Yoshihiro
Published: March 2006

We have completed rapid syntheses of [18F]butyrophenone neuroleptics ([18F]haloperidol and [18F]spiperone) from their nitro precursors in high radiochemical yields (up to 21%) by combining a one-step nitro-fluoro exchange reaction and a novel high performance liquid chromatography (HPLC) separation method. The synthesis time was ca. 95 min and both the radiochemical and chemical purities of the labeled products were over 99%.
Metal Bis((perfluoroalkyl)sulfonyl)amides as Novel Lewis Acid Catalysts in Diels-Alder Reaction
Authors: Kobayashi Hiroshi , Nie Jin , Sonoda Takaaki
Published: March 2006

Some stable and lipophilic metal bis((perfluoroalkyl)sulfonyl)amides are prepared and employed as remarkable Lewis acid catalysts in the Diels-Alder reaction of cyclopentadiene with methyl vinyl ketone.
Catenation of 2,2′-Bis(ethylthiomethyl)biphenyl with Copper(I) Bromide
Authors: Toyota Shinji , Matsuda Yohei , Oki Michinori , Akashi Haruo
Published: March 2006

Treatment of 2-(ethylthiomethyl)phenyllithium with copper(I) bromide afforded a polymeric coordination compound in which 2,2′-bis(ethylthiomethyl)biphenyl molecules were linked by copper(I) bromide cores. This polymeric complex dissociates on dissolution in organic solvents and reforms on recrystallization from the solution. Other copper(I) salts also gave similar compounds, when reacted with the lithium compound.
Formal Hydroallylation of Carbon-Carbon Triple Bonds via Tantalum-Alkyne Complexes. Stereoselective Preparation of 1,4-Dienes
Authors: Takai Kazuhiko , Yamada Masashi , Odaka Hidetoshi , Utimoto Kiitiro , Fujii Takeshi , Furukawa Isao
Published: March 2006

Treatment of tantalum-alkyne complexes with lithium salts of allylic alcohols in DME-benzene-THF (1:1:1) at 25 °C for several hours gives 1,4-dienes stereoselectively in good to excellent yields.