bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthetic Reactions by Complex Catalysts. XXIV. A New Catalyst of Copper-Isocyanide Complex for the Michael Addition
Authors: Saegusa Takeo , Ito Yoshihiko , Tomita Shimpei , Kinoshita Hideo 
Published: July 2006

Abstract
It has been found that some binary systems of a copper compound (or metallic compounds) and an isocyanide catalyze the Michael addition reaction. As the copper component, Cu2O, metallic copper and copper acetylacetonate are effectual, whereas CuCl, CuCl2, and CuO are ineffectual. The catalyst of copper isocyanide complex is characterized by the selective activation of cyano olefin compounds such as acrylonitrile. This was demonstrated by the competitive addition of an active hydrogen compound to acrylonitrile and methyl acrylate. Some results of kinetics and spectroscopic studies have been explained by assuming a scheme involving coordination of olefin onto copper-isocyanide complex.
Reaction of Enol Ethers with Carbenes. X. Ring Opening of 2,2-Dichlorocyclopropyl Phenyl Sulfides
Authors: Parham William E , Kajigaeshi Shoji , Groen Siemen H 
Published: July 2006

Abstract
The ring opening reactions of six known or new 2,2-dichlorocyclopropyl phenyl sulfides have been carried out with potassium t-butoxide in t butyl alcohol and with pyridine. The products were enynes, butadienes, allenes and, as minor products, α,β-unsaturated aldehydes containing the phenylmercapto group. Reaction of a mixture of cis- and trans-1,1-dichloro-2-methyl-3-phenylmercaptocyclopropane (2) with pyridine gave unchanged trans-isomer. This apparent selectivity is explained on the basis of the steric effects for ring opening.
The Reaction of Diaryl Disulfides with the Cyanide Ion
Authors: Tanaka Kazuhiko , Hayami Jun-ichi , Kaji Aritsune 
Published: July 2006

Abstract
The reaction of symmetrical disulfides with the cyanide ion in various solvents has been investigated. The reaction modes may be summarized as follows: (1) Dialkyl disulfides and diaryl disulfides with electron-with-drawing substituents react with the cyanide ion in DMSO or DMF to give the corresponding monosulfides. (2) Diaryl disulfides with electron-donating substituents react with DMSO to yield aryl methyl sulfides. (3) Diaryl disulfides are cleaved by the cyanide ion into thiolate anions and aryl thiocyanates, which then react with alcohol to afford alkyl aryl sulfides.
The Photochemical Reduction of Nitrobenzene and Its Reduction Intermediates. X. The Photochemical Reduction of the Monosubstituted Nitrobenzenes in 2-Propanol
Authors: Hashimoto Shizunobu , Kano Koji 
Published: July 2006

Abstract
The photochemical reduction of the monosubstituted nitrobenzenes has been investigated in 2-propanol under a nitrogen atmosphere. The nitrobenzenes with electron-withdrawing groups on meta- and para-positions (p-NO2, m- and p-CN, m- and p-COOC2H5, p-COOCH(CH3)2, and m- and p-COOH) were photoreduced to the corresponding anilines, and nitrobenzene and the para-substituted nitrobenzenes with electron-donating groups (p-CH3 and p-OCH3) were photoreduced to the corresponding phenylhydroxylamines. p-Nitroaniline and p-nitrophenol were unreactive toward the photoreduction. In the experiments on the determination of the quantum yields for the nitrobenzenes’ disappearance upon irradiation with a 313- or 366-nm light, it has been found that there is a linear correlation between the log-values of the relative quantum yields of the substituted nitrobenzenes and nitrobenzene and the Hammett constants, and the ρ value was + 1.5. The results obtained suggest that the hydrogen-abstraction reaction of the photoexcited nitrobenzenes may proceed electrophilically.
Synthesis of Chelating Agents. VIII. Synthesis and Acid Dissociation of 3,3-Dimethylbutane-1,2-dinitrilo-N,N,N′,N′-tetraacetic Acid
Authors: Yanagihara Yuzo , Yano Tairoku , Kobayashi Hiroshi , Ueno Keihei 
Published: July 2006

Abstract
3,3-Dimethylbutane-1,2-dinitrilo-N,N,N′,N′-tetraacetic acid (BEDTA) has been synthesized by the carboxymethylation of 3,3-dimethylbutane-1,2-diamine (BEDA). The stepwise acid dissociation constants determined by the potentiometric method were found to be pKa1=6.26 and pKa2=9.78 for BEDA and pKa1=2.1, pKa2=3.62, pKa3=5.29, and pKa4=11.6 for BEDTA at 25°C and an ionic strength of 0.1 (KCl). The values were discussed in relation to molecular structures.
ESR Investigation of Copper Ions on Several Kinds of Cation Exchange Resins
Authors: Umezawa Kayoko , Yamabe Takeo 
Published: July 2006

Abstract
Copper ions on several kinds of cation exchange resins were investigated by means of ESR spectroscopy. It was found that the motion of copper ions is restricted in the network of the ion exchange resin, and that the mobility of copper ions is closely connected with the chemical interaction of the copper ions with the fixed ionic groups of the resins. The mobility of copper ions is in the order of; on the sulfonic group&gt;on the phosphonic group&gt;on the carboxylic group&gt;on the iminodiacetate group. This sequence is the reverse of the selectivity for the copper ion. The effect of the water molecules involved in ion exchange resins is also considered, and the copper species on each ion exchange resin are assumed.
Aroyl Arenesulfonyl Peroxides. III. Thermal Decomposition of p-Chlorobenzoyl p-Toluenesulfonyl Peroxide.
Authors: Hisada Ryuki , Kobayashi Michio , Minato Hiroshi 
Published: July 2006

Abstract
p-Chlorobenzoyl p-toluenesulfonyl peroxide was synthesized. Its spontaneous decomposition in benzene or in carbon tetrachloride did not follow a first-order rate equation because of the rate acceleration due to p-toluenesulfonic acid produced. When powdery magnesium oxide was suspended in benzene, isomerization to p-chlorophenyl p-toluenesulfonyl carbonate was completely inhibited, and the rate followed a first-order equation. The products of decomposition (p-chlorobiphenyl, p-chlorobenzoic acid, p-toluenesulfonic acid, phenyl p-toluenesulfonate, etc) were accounted for in terms of initial formation of p-toluenesulfonyloxy and p-chlorobenzoyloxy radicals. p-Toluenesulfonyloxy radical was found to be a very effective hydrogen-abstractor with little tendency to add to benzene.
Preparation of Cyclamenaldehyde by Selective Hydrogenation in Some Cobalt Carbonyl Complex Catalysts under Oxo Conditions
Authors: Kogami Kunio , Takahashi Osamu , Kumanotani Ju 
Published: July 2006

Abstract
Selective hydrogenation of p-isopropyl-α-methylcinnamaldehyde to cyclamenaldehyde in some cobalt carbonyl complex catalyst systems has been investigated under several oxo conditions. The yield of the aimed aldehyde was improved as much as 84 to 86.3% under controlled conditions. Selectivity of the hydrogen increased with the decrease of temperature and the increase of partial pressure of hydrogenation in a water gas. A maximum yield (84%) was obtained with solvents such as isopropyl ether and hexane when used in 2-fold volume for the cinnamaldehyde. A tris(2-bromoethyl) phosphite-substituted cobalt carbonyl complex catalyst gave the best yield (86.3%) as compared with catalysts unsubstituted and substituted with PR3, P(OR)3, and PO(OR)3(R=alkyl, aryl).
Photodecomposition of Vinyl Iodide in Gas Phase
Authors: Yamashita Shigeru , Noguchi Shigeo , Hayakawa Teruo 
Published: July 2006

Abstract
Photodecomposition of vinyl iodide has been studied at 313 and 254 mμ using a high intensity light source. Because of high concentration of the radicals formed primarily due to the high intensity of the light source, only the inter-radical reactions were taken into account in considering the secondary processes.
Both molecular and free radical processes have been observed in the primary process and the ratio of the contribution of molecular process to free radical process was found to be about 1 : 6 in the wavelength range studied. A slight energy dependence of kd⁄kc, the ratio of the rate of disproportionation reaction to that of combination reaction of vinyl radicals, was found in the secondary processes.
The Calculation of the Rates of Intramolecular Nonradiative Transitions in Benzene
Authors: Shimakura Noriyuki , Fujimura Yuichi , Nakajima Takeshi 
Published: July 2006

Abstract
Intramolecular nonradiative transition rates for various interstates of benzene were calculated from the standpoint of the breakdown of the Born-Oppenheimer approximation. The electronic parts of the coupling matrix elements were explicitly evaluated. These parts vary in the range of 10−1–10−3 Å−1. The nonradiative transition rates for the 1E1u→1B1u,1B2u transitions were predicted to be appreciable. The rate for the 1B1u→1B2u transition vanishes as long as the geometrical structure of the 1B1u state is assumed to be of the D6h symmetry. These results are compared with the experimental nonradiative transition widths recently reported by Jortner et al.
A Chlorine NQR Study of Some Perchloro-compounds
Authors: Hashimoto Masao , Mano Koichi 
Published: July 2006

Abstract
The NQR frequencies of chlorines in seven perchloro-compounds were measured at 77°K and above. The assignments of the frequencies were made for each compound. It was found that the resonance frequency is considerably influenced by the electrostatic repulsion between chlorine atoms due to the close Cl···Cl distances. For several compounds, the resonance was found to fade out at rather low temperatures.
The Laser Photolysis of Methylene Blue in the Presence of p-Chlorophenylglycine
Authors: Obi Kinichi , Makino Hiroshi 
Published: July 2006

Abstract
The photoreduction of methylene blue by a ruby laser light has been studied. The kinetic treatment and the measurement of the apparent activation energy show that, under the high-intensity irradiation, the excited triplet state of methylene blue plays a main role in the photoreduction by p-chloro phenylglycine. The apparent activation energy of the reduction of methylene blue is reduced from 7.4 to 2.8 kcal as the laser light energy increases from 23 to 530 mJ.
The Dye-sensitized Photooxygenation of Hexamethyleneammonium Hexamethylenedithiocarbamate by Xanthene Dyes
Authors: Yamase Toshihiro , Kokado Hiroshi , Inoue Eiichi 
Published: July 2006

Abstract
The photoelimination of hexamethyleneammonium hexamethylenedithiocarbamate (HMTC) can be sensitized by xanthene dyes, such as rose bengal and eosine yellowish. In contrast to the direct photolysis results, the presence of HMTC in the dye-sensitized decomposition produces no carbon disulfide and consumes oxygen during the irradiation. The quantum yield of photoelimination in an aerated ethanol solution was measured. The quantum yield was almost unchanged on the variation of the xanthene dye concentration from 10−5 to 10−6m. This is different from the former observation that there was an apparent tendency for the quantum yield to decrease monotonously with an increase in the thiazine dye concentration. The singlet oxygen mechanism, in which the photochemical reaction is initiated by the interaction between the triplet dye and the ground-state oxygen molecules, has been inferred for the dye-sensitized photoelimination of HMTC. It has been explained in terms of the effect of 1,4-diazabicyclo [2.2.2] octane, β-carotene, and tetramethylethylene in reducing the quantum yield. The photooxygenation of HMTC by dyes seemed to be caused by attack of the singlet oxygen on the thiocarboxyl-ion group, which has a rate constant of 108m−1sec−1 in ethanol.
Interaction between Phenothiazine Triplet State with Several Electron Acceptors
Authors: Iwaoka Teiki , Kokubun Hiroshi , Koizumi Masao 
Published: July 2006

Abstract
As an extension of the previous paper (This Bulletin, 44, 341 (1971)) which proposed the formation of a certain charge transfer complex between triplet phenothiazine (PTHT) and oxygen or dimethylisophthalate, the similar donor-acceptor interaction has been studied between PTHT and several other acceptors such as dimethylterephthalate (DMTP), nitrobenzene, dinitrobenzene, and terephthalonitrile in deaerated ethanol solutions. In case of DMTP, studies have been made also in cyclohexane. It has been established that all the acceptors except nitrobenzene attack PTHT with the diffusion controlled rate constant and that in ethanol they give rise to free radical ions and/or solvent shared ion-pair. In cyclohexane, however, no transient species other than triplet has been detected.
Electronic Spectra and Structures of Organic π-Systems. VI. Electronic States of Diazomethane, Ketene, Diazocyclo-pentadiene and Benzenediazonium Ion
Authors: Yoshida Zen-ichi , Kobayashi Tsunetoshi 
Published: July 2006

Abstract
The electronic states of diazomethane, ketene, diazocyclopentadiene and benzenediazonium ion were studied by the semi-empirical ASMO LCAO SCF CI method. Both π- and \barπ-systems were taken into consideration. Two types of approximations, Mulliken’s formula and a new semitheoretical formula, were used in the evaluation of the core resonance integrals. The latter gives satisfactory results though it contains no arbitrary adjustable parameters. The longest wavelength singlet-singlet transition of diazomethane, ketene or diazocyclopentadiene is 1π–1\barπ, and that of benzenediazonium ion 1π–1π.
Transient Species Obtained by the Flash Photolysis of Chloranil in Various Solutions
Authors: Kawai Kiyoshi , Shirota Yasuhiko , Tsubomura Hiroshi , Mikawa Hiroshi 
Published: July 2006

Abstract
Transient absorption spectra have been obtained by the flash photolysis of chloranil in various organic solvents. In trichlorotrifluoroethane, two T-T′ absorption systems of chloranil were obtained with well-resolved vibrational structures. In tetrahydrofuran, on the other hand, absorption spectra mostly consist of semiquinone radical formed by the hydrogen abstraction from solvent. In benzene and in acetone, the first T-T′ absorption system was much more diffuse and was accompanied by a weak, broad absorption at longer wavelength (λ&gt;550 nm) which might be assigned to a charge transfer absorption from triplet chloranil as acceptor and the solvent molecule as donor. In acetone and in methanol, it has also been found that there is an equilibrium between semiquinone radical and semiquinone anion.
Stereoselective Formation of Isomers of the Bis(l-aspartato)-l-(or d-)alaninatocobaltate(III) Complex
Authors: Matsuda Toshitsugu , Okumoto Tetsuro , Shibata Muraji 
Published: July 2006

Abstract
The reaction of racemic α-alanine, in the presence of active charcoal, on a reaction mixture of the [Co(CO3)3]3− complex with l-aspartate led to the stereoselective formation of the [Co(l-asp)n(ala)3−n]n− (n=0—3) complexes. By means of ion-exchange chromatography and a recrystallization procedure, three stereoisomers of the bis(l-aspartato)alaninato complex have been obtained; mer1-Λ-[Co(l-aspH)2(l-ala)]·H2O, mer2-Λ-[Co(l-aspH)2(l-ala)]·2H2O, and fac-Δ[Co(l-aspH)2(d-ala)]·4H2O (where the mer1 and mer2 isomers have different geometries). These isomers have been characterized by comparing their CD and PMR spectra with those of the corresponding isomers obtained using l- or d-alanine in place of racemic alanine. The fac/mer ratio has been estimated to be ca. 64/36. The Δ/Λ AIA ratio in the fac isomer has been estimated to be ca. 95/5, while the Δ/Λ ratio in both the mer1 and mer2 isomers has been estimated as ca. 25/75.
Studies on the Isomerization of 2,4-Dinitrophenylhydrazones of Some Aliphatic α-Keto Acids and the Preparation of Their Geometrical Isomers
Authors: Katsuki Hirohiko , Tanegashima Chizuko , Tokushige Masanobu , Tanaka Shozo 
Published: July 2006

Abstract
Cis-trans isomerization of 2,4-dinitrophenylhydrazones of some aliphatic α-keto acids takes place in water and some organic solvents by the catalysis of hydrogen ions. Trans isomer is more stable than cis isomer for lower keto acids and the reverse is the case for higher keto acids. The fraction of cis isomer in isomeric mixture at equilibrium in organic solvents such as ethyl acetate and ethyl ether, saturated with 6n hydrochloric acid, was larger than that in aqueous solution. The two isomers could be separated by means of the difference in their solubility characteristics in 1n sodium carbonate except for some keto acids with tertiary or quaternary β-carbon. Melting points of some pairs of the hydrazone isomers were found to be the same when measured by the usual method. This is due to the isomerization of one isomer to the other which takes place during the course of heating.
The Dissociation Constants of Weak Acids in a Methanol-Water Mixture
Authors: Kondo Yasuhiko , Tokura Niichiro 
Published: July 2006

Abstract
The theoretical expression of the Henry constant has been derived on the basis of the concept of an ideal associated mixture for the system in which a solute, M, exists as such clusters as M·(H2O)j·(MeOH)z−j, which are related to each other by the equation:
M·(H2O)j−1·(MeOH)z−j+1+H2O\oversetKj\ightleftarrowsM·(H2O)j·(MeOH)z−j+MeOH
Making use of the theoretical expression, the transfer-free energies of halogen acids from water to water-methanol mixtures and the dissociation constants of weak acids in water-methanol mixtures have been analyzed and the following equilibrium constants have been obtained for a proton, assuming that a proton is in a higher free energy state in methanol than in pure water, while a counter ion is in the same free-energy state:
K 1=210, K2\doteqdot16, K3\doteqdot2,K4\doteqdot1
The maximum phenomena observed for the dissociation constants of charged acids in the same mixture could be reproduced by the combination of the above Henry constants; emphasis has been placed on the importance of the assumption of a multi-step solvation mechanism.
A Consideration of Orbital Interaction in Nitrogen Extrusions of Cyclic Azo Compounds
Authors: Inagaki Satoshi , Fukui Kenichi 
Published: July 2006

Abstract
The stereochemical paths of nitrogen extrusions from cyclic azo compounds have been examined from the point of view of particular orbital interaction. The stereoselectivity of the recyclization of 1-pyrazoline derivatives and the homologues on the extrusion can be understood in terms of interaction between the frontier orbitals of the C–N–N–C σ-bond system and of N–N π-bond. Other cyclic azo compounds are found also to behave consistently with the direction of the particular orbital interaction between the relevant parts e.g., strained σ-bonds, π-bonds and lone pairs, and two weakened C–N bonds, and of the interaction between approximate p orbitals at the α carbons with respect to the nitrogen and unstrained σ-bond to be cleaved.
Studies of Thioiminocarbonates. II. The Cyanide Ioncatalyzed Addition of Alcohols to Thiocyanates
Authors: Tanaka Kazuhiko 
Published: July 2006

Abstract
It was found that thiocyanates reacted with methanol in the presence of a catalytic amount of cyanide ion to give thioiminocarbonates. The effects of other catalysts upon the addition of methanol to thiocyanates were examined: the azide ion and the methoxide ion were effective, while triethylamine, sodium thiocyanate, potassium iodide, triphenylphosphine, sodium acetate, and mercuric cyanide were ineffective. A plausible reaction mechanism involving the addition of the cyanide ion to thiocyanates was proposed.
Thallium(III) Chloride Tetrahydrate as a Lewis Acid Catalyst for Aromatic Alkylation and Acylation
Authors: Uemura Sakae , Sohma Kazuhiro , Okano Masaya 
Published: July 2006

Abstract
From a study of aromatic alkylation and acylation using TlCl3·4H2O catalyst, it was revealed that this metal chloride was a milder Lewis acid catalyst than AlCl3 and FeCl3 and was similar in activity to ZnCl2. Although the yields of the products were generally low, the characteristics of this catalyst were observed in the formation of β,β′-dimethylstyrene and benzoylacetone upon the respective methallylation and acetylation of benzene and in the fact that the hydrated chloride was more effective than the anhydrous one. In a sharp contrast to aromatic bromination, Tl(OAc)3 showed little activity in these reactions.
Studies of Peptide Antibiotics. XXVII. Synthesis of an Analog of Gramicidin S Containing a Glycine Residue in Place of a Proline
Authors: Matsuura Shuji , Waki Michinori , Izumiya Nobuo 
Published: July 2006

Abstract
[Gly5]-Gramicidin S in which one l-proline residue at 5-position in gramicidin S is replaced with glycine was synthesized and tested for antibacterial properties. The cyclic decapeptide obtained was as active as natural gramicidin S. It was suggested that the mode of antibacterial activity of [Gly5]-gramicidin S and its conformation are similar to those of GS.
Sulfenylation of Active Methylene Compounds with Sulfenamides
Authors: Kumamoto Takanobu , Kobayashi Susumu , Mukaiyama Teruaki 
Published: July 2006

Abstract
Equimolar reactions of sulfenamides derived from secondary alkylamines with active methylene compounds afforded mono-sulfenylated compounds in good yields. The reactions of 2 mol of sulfenamides derived from imides with 1 mol of active methylene compounds in the presence of a base gave di-sulfenylated compounds. It was found that α-mono-sulfenylated ketones were prepared by the reactions of enamines with sulfenamides derived from imides. α-gem-Di-sulfenylated ketones were prepared by the reactions of α-mono-sulfenylated ketones with sulfenamides derived from imides in the presence of a base. The preparation and reactions of N-phenylthiobenzamidine hydrochloride were also examined.
The Palladium-catalyzed Ferrocenylation of Olefins
Authors: Kasahara Akira , Izumi Taeko , Saito Genji , Yodono Minoru , Saito Ryu-ichi , Goto Yoshiaki 
Published: July 2006

Abstract
Ferrocenylpalladium chloride, prepared in situ from chloromercuriferrocene and lithium chloropalladite, reacts readily with various olefins to produce alkenylferrocene derivatives. Enol esters and allylic alcohols also react to form (2-oxoalkyl)- and (3-oxoalkyl)-ferrocene derivatives. The synthesis of 1,1′-dialkenylferrocene derivatives from 1,1′-bis(chloromercuri)ferrocene, olefins and palladium salt is also reported. The reaction may proceed by means of a catalytic amount of the metal salt and by the aid of cupric chloride; it provides an extremely convenient method for the synthesis of a wide variety of ferrocene derivatives.
Spectroscopic Studies on the Tautomers of Heptane-2,4,6-trione and Its Methylated Homologues
Authors: Sagara Fumio , Kobayashi Hiroshi , Ueno Keihei 
Published: July 2006

Abstract
3,5-Dimethylheptane-2,4,6-trione and 3-methylheptane-2,4,6-trione are synthesized by methylationheptane of-2,4,6-trione via alkali metal enolates or an enamine intermediate of the mother compound. In keto-enol tautomerism, the latter two compounds take triketo-, monoenol-, and bisenol forms, while the first one exists in triketo and monoenol forms, being unable to take a bisenol form. NMR spectra of the tautomers are assigned by combining with IR data. Keto-enol ratio in a range of solution phases at various temperatures are estimated by NMR method and effect of the branched methyl groups upon the keto-enol tautomerism is discussed.
The Crystal Structure of 1-Ethyl-5-bromouracil. I. The Crystal Structure of the Form I Crystal of 1-Ethyl-5-bromouracil
Authors: Mizuno Hiroshi , Fujiwara Takaji , Tomita Ken-ichi 
Published: July 2006

Abstract
1-Ethyl-5-bromouracil, C6H7N2O2Br, is crystallized in two forms. Crystals of the form I are monoclinic with four molecules in a unit cell of dimensions; a=7.89, b=12.01, c=9.71 Å, β=121.0°, space group P21⁄c, Three-dimensional intensity data were collected by diffractometer with Mo-Kα radiation. The structure was determined by heavy atom method and refined by the block-diagonal least-squares method. The final R-value was 0.052 for all observed reflections. The molecules are joined together in pairs around a center of symmetry with two N–H···O hydrogen bonds connecting N(3) to carbonyl oxygen O(4), and stacked with the base plane tilted each other.