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Two types of new anion-exchange stationary phases were readily prepared by the reaction of porous particles of chloromethylated styrene–divinylbenzene copolymer with various amines. The stationary phases Mn, where n is the length of alkyl chain, were obtained by the reaction with N,N-dimethylalkylamines. The reaction with N,N,N′,N′-tetramethyldiaminoalkanes also afforded the stationary phases Dn with a terminal functional group, where n is the length of methylene bridge. The HPLC separations of monosaccharides, disaccharides and oligosaccharides were successfully performed on these stationary phases using electrochemical detection with a Ni–Ti alloy working electrode in alkaline eluents. The effects of chemical structures of stationary phases on the separation of carbohydrates are described.

A three-layer membrane for optical pH chemical sensors has been developed consisting of layers of polyester support, chitosan-indicator and polyvinly alcohol-titanium dioxide for reflection. The chitosan membrane was more stable and easier for immobilizing of benzopurprine 4B or fluorescein isothiocyanate than a cellulose membrane on which polyvinyl alcohol with titanium dioxide and calcium carbonate was coated and heated at 140°C in nitrogen atmosphere followed by dissolving of calcium carbonate to form a porous water-resistant membrane for reflection of light. The sensor membrane shows a pH-induced color change than makes it capable of measuring pH in the 3-7 range.

Seven chiral stationary phases (CSPS) were prepared by bonding axially dissymmetric 2′-substituted-1,1′- binaphthyl-2-carboxylic acids to aminoalkylsilanized silica gels through an amide linkage, and the effect of the 2′-substituents (CN, COOH, CONH 2 , CONHEt, CONEt 2 and OCH 3 ) was investigated for the high-performance liquid chromatographic (HPLC) separation of enantiomers. Among these CSPS, that which had a 2′-carboxyl substituent showed the best performance and efficiently discriminated several enantiomeric amino acids, amines and alcohols as their 3,5-dinitrophenyl derivatives, and biaryls bearing 2,2′-polar substituents, by normal-phase HPLC. Stereoselective π-donor-acceptor interaction and dipole stacking interaction between the CSPs and the analytes seem to play a critical role in the enantioseparation.

High-performance liquid chromatographic separation of monosaccharides and disaccharides was successfully carried out with novel anion-exchange stationary phases prepared from (CH3)2N-(CH2)n-N(CH3)2 and porous particles of chloromethylated styrene-divinylbenzene copolymer coupled with a pulsed amperometric detector.

We describe the preparation and effectiveness of novel chiral stationary phases involving two different stereogenic centres, axially chiral 1,1'-binaphthalene-2,2'-dicarboxylic acid coupled with chiral 1-phenylethylamine

High-performance liquid chromatographic separation of monosaccharides and disaccharides was successfully carried out with novel anion-exchange stationary phases prepared from (CH3)2N-(CH2)n-N(CH3)2 and porous particles of chloromethylated styrene-divinylbenzene copolymer coupled with a pulsed amperometric detector.

N,N-ジメチルホルムアミド中,塩化ニッケル,トリフェニルホスフィン,ヨウ化ナトリウム,亜鉛末から,超音波照射下,in situで発生させた低原子価ニッケル錯体によるスルホン酸アリール類のUllmann型カップリング反応を研究した。スルホン酸アリール類は,メタンスルホン酸

The dimerization of propene by potassium catalyst was carried out at 180 °C in n-heptane to give 4-methyl-1-pentene as a major product. The effects of the addition of metal powders, potassium alkoxides and tertiary amines were investigated. The selective production of 4-methyl-1-pentene on adding metal powders increased in the order of Cu, Ag>Mg, Co>Al, Fe, Ni, Zn. When long-chain alkoxides were added to the potassium–copper catalyst system, potassium catalyst was observed to be dispersed, the relative reaction rates increased, and the isomerization of 4-methyl-1-pentene formed was retarded. Thus, the selectivity increased more than 90% after 40% conversion of propene. The potassium–copper–aliphatic tertiary amine-catalyst system caused the yield of 4-methyl-1-pentene to increase in a similar manner to the potassium–copper–alkoxide-catalyst system and inhibited the formation of the carbonaceous substance covering the surface of the catalyst, and the selectivity was not lowered after a higher conversion of...

Base-catalyzed autoxidation of fluorene to fluorenone has been carried out in an aqueous potassium hydroxide–benzene two-phase system in the presence of 18-crown-6 as a phase transfer catalyst. The initial rate of oxidation is proportional to the amount of fluorene. The addition of 18-crown-6 leads to the increased concentration of potassium hydroxide and water in the benzene phase, which is responsible for the increased rate of oxidation. Increasing the concentration of potassium hydroxide in the aqueous phase increases the concentration of 18-crown-6 and potassium hydroxide in benzene, resulting in a large increase in the rate of oxidation. The ease of oxidation with respect to the base is KOH>NaOH>LiOH>Ba(OH)2. Less polar solvents such as cyclohexane used as an organic phase decrease the oxidation rate.

Asymmetric reduction of acetophenone with chiral reagents from lithium tetrahydroaluminate and (1S,2S)-1,2-diphenylethanediol or (1S,2S)-N,N′-diethyl-1,2-diphenylethanediamine in the presence or absence of added ethanol is studied by aluminum-27 NMR spectroscopy.

A kinetic study has been made of the cobalt acetate-catalyzed decomposition of t-butyl hydroperoxide in acetic acid at 40.4°C, and the effects of added lithium salts on the decomposition rate have been studied. The observed rate law for the cobalt acetate-catalyzed decomposition is: v=k2[Co(II)][t-C4H9OOH]+k3[Co(II)]2[t-C4H9OOH]. When lithium halides (chloride and bromide) are added to this system, the cobalt acetate is changed to cobaltous halide and the rate of decomposition is markedly decreased. In the case of lithium bromide the hydroperoxide decomposition is accompanied by the generation of molecular bromine. The mechanisms for the bromine formation will be discussed. The role of these cobalt salts in the course of autoxidation in relation to the hydroperoxide decomposition will also be discussed.

カルボン酸金属塩の熱分解機構を総合的に整理し検討する研究の一環として, 5 種類の脂肪酸の1 1 種類の金属塩の熱分解反応をしらべた。金属塩の熱分解開始温度は, 金属の電気陰性度が増加するほど, また脂肪酸の炭素数が減少するほど, 低くなる傾向にある。また, アルカリ金属塩, アルカリ土類金属塩からはケトンのみが生成するが, 重金属の塩からは, ケトンの他に酸および酸無水物が生成する。これらの事実は, 標準状態における熱力学的計算の結果と傾向がよく一致し, 金属の酸化物と炭酸塩との相対的な安定性が熱分解生成物の種類を規定する重要な因子であることを示唆するものであり, 金属の脱離を律速段階とする4 員環遷移状態を含む求核的な機構でよく説明される。また酸無水物がケトン生成の中間体であると考える説は否定される。

The reactions between the phenyl radical and copper(II) complexes in acetic acid and in acetonitrile were investigated. It was found that the phenyl radical produced from the thermal decomposition of benzoyl peroxide in acetic acid is oxidized by the copper(II) ion to give a considerable amount of phenyl acetate. With cupric propionate, chloride, and bromide, “ligand-transfer” products, i.e., phenyl propionate, chloro-, and bromobenzene, respectively, were also obtained. In addition, a larger yield of the oxidation product was obtained from a 1 : 1 complex than from a 1 : 3 complex of copper(II)-phenanthroline. These facts, together with the results on solvent effects, can be successfully explained on the basis of a ligand-transfer mechanism rather than an electron-transfer mechanism. The effects of substituents of benzoyl peroxide on the reaction were an electron-transfer mechanism. The effects of substituents of benzoyl peroxide on the reaction were so small that one cannot decide whether the ligand-tra...

The reductive coupling reactions of some chloromethylbenzene derivatives with ferrous and cuprous chloride in ethanol or in acetonitrile and the effect of some additives on this reaction have been investigated. Benzotrichloride has been reduced selectively to tolan tetrachloride with ferrous chloride, while with cuprous chloride-ethylenediamine (a stronger reductant than ferrous chloride) mixtures of tolan and tolan dichloride or tolan tetrachloride are obtained depending on the condition. Similarly benzal chloride, diphenylmethyl chloride and diphenyldichloromethane are also reduced to give coupling products. In case of ferrous chloride the addition of ethylenediamine or pyrophosphoric acid raises the yield considerably and in case of cuprous chloride selection of the ratio, organic halide: copper (I): ethylenediamine, makes it possible to control the product distribution. The reaction mechanism and the effect of the additives are discussed.

Oxidation of methylnaphthalenes with aqueous sodium bichromate under pressure was carried out to obtain naphthoic acids. β-naphthoic acid obtained from β-methylnaphthalene was extremely pure. The yield was about 900% and independent on the reaction temperatures between 230°c and 270deg;c when the reaction was carried out under 20 atm CO2 pressure. But without CO2 addition the yield was depressed to 70-80%. As the Oxidizing ability of bichromate is considerably lowered in strong alkaline solution, carbon dioxide was used to neutralize the sodium hydroxide produced during the reaction, thus keeping the reaction medium nearly neutral. Molar ratio of bichromate to methylnaphthalene above 1.2 was necessary to obtain the high yield. The concentration of bichromate above 25% gave poor result, especially when the reaction was carried out at low bichromate ratio without CO2. Oxidation of crude methylnaphthalene oil gave the mixture of naphthoic acids, and the molar ratio of β- to α-naphthoic acid was established as about 2 from the melting point curve.

Asymmetric reduction of acetophenone with chiral reagents from lithium tetrahydroaluminate and (1S,2S)-1,2-diphenylethanediol or (1S,2S)-N,N′-diethyl-1,2-diphenylethanediamine in the presence or absence of added ethanol is studied by aluminum-27 NMR spectroscopy.

The dimerization of propene by potassium catalyst was carried out at 180 °C in n-heptane to give 4-methyl-1-pentene as a major product. The effects of the addition of metal powders, potassium alkoxides and tertiary amines were investigated. The selective production of 4-methyl-1-pentene on adding metal powders increased in the order of Cu, Ag>Mg, Co>Al, Fe, Ni, Zn. When long-chain alkoxides were added to the potassium–copper catalyst system, potassium catalyst was observed to be dispersed, the relative reaction rates increased, and the isomerization of 4-methyl-1-pentene formed was retarded. Thus, the selectivity increased more than 90% after 40% conversion of propene. The potassium–copper–aliphatic tertiary amine-catalyst system caused the yield of 4-methyl-1-pentene to increase in a similar manner to the potassium–copper–alkoxide-catalyst system and inhibited the formation of the carbonaceous substance covering the surface of the catalyst, and the selectivity was not lowered after a higher conversion of...

The reductive dehalogenation of aryl chlorides as well as other organic halides was facilitated with nickel(II) chloride–zinc–water in hexamethylphosphoric triamide irradiated with ultrasound.

The low valent nickel complexes generated in situ from nickel(II) chloride, triphenylphosphine, sodium iodide, and zinc powder in dimethylformamide catalyze the Ullmann-type homo-coupling of aryl trifluoromethanesulfonates to biaryls under ultrasounds irradiation.

Ultrasonic irradiation facilitates the methylenation of carbonyl compounds with zinc–diiodomethane reagent in tetrahydrofuran at room temperature.

Both enantiomers of 1,1′-binaphthyl-2,2′-dicarboxylic acid (100% ee’s by HPLC) were conveniently obtained in high yields (ca. 80% of the theory) via fractional crystallization of the (S)-1-phenylethylamide diastereomers of the racemic acid followed by treatment with thionyl chloride and then alkaline hydrolysis.

(S)-1,1′-Binaphthyl-2,2′-dicarboxylic acid was chemically bonded to an aminopropylsilanized silica through amido linkage to give a chiral stationary phase for HPLC, which efficiently differentiated enantiomeric aliphatic alcohols as 3,5-dinitrophenylcarbamates.