Hideto Shosenji

Chromatographic separation of geometrical isomers using highly oriented polymer-immobilized silica gels

Poly(octadecyl acrylate) having a reactive group at one side of the terminal group was synthesized and immobilized on porous silica gels. Differential scanning calorimetric measurement indicated that the immobilized polymer underwent a crystal-to-isotropic phase transition on silica gels. Using a packed column, a remarkably high separation factor for geometrical isomers of stilbene was observed in the crystal-state temperature range, although no similar separation was observed with octadecylated silica gels. It was estimated by calculation of the HOMO that this specific retention includes charge-transfer interactions from double bonds of solutes to acrylate moieties of the stationary phase.

Enantioselectively catalyzed oxidation of 3,4-dihydroxy-l-phenylalanine by N-lauroyl L or D-histidine-Cu(II) complex in CTABr micelles.

Abstract In order to investigate the enzyme model reaction the oxidation of 3,4-dihydihydroxy-L-phenylalanine(L-DOPA) was carried out using optically active catalyst, N-lauroyl L or D-histidine-Cu(II) complex(L or D-LauHis-Cu(II)), showing appreciable enantioselectivity in the presence of the mixed micelles with CTABr.

Enantioselectively catalyzed hydrolysis of p-nitrophenyl esters of N-protected L or D-amino acids by optically active hydroxamic acid and dipeptides

Abstract Catalyzed hydrolysis of p-nitrophenyl esters of N-protected L or D-phenylalanine by optically active hydroxamic acid or dipeptides in the presence of CTABr micelles showed high enantioselectivity (D/L=5.68 for L-ZLysZ(MHX)), demonstrating control of the direction of the enantioselectivity based on the balance of the structures of the nucleophile and substituent.

Enantioselectively catalyzed hydrolysis of p-nitrophenyl esters of N-protected L-amino acids by N-lauroyl L or D-histidine in CTABr micelles.

Abstract Remarkable dependencies of the rate constants and enantioselectivities on the substituents and protecting groups were demonstrated by the catalyzed hydrolysis of p-nitrophenyl esters of various N-protected L-amino acids by L or D-LauHis in the presence of mixed micelles with CTABr.

Study of Pinacol Coupling Reaction to Synthesize Functional Macrocyclic Molecules

[2.1.2.1]Metacyclophane ([2.1.2.1]MCP) 3 containing hydroxyl groups at the bridge is obtained by a pinacol coupling reaction using aluminum powder. The Albright-Gordman oxidation of [2.1.2.1]MCP 3 yielded tetracarbonyl derivative 4 , and the following condensation reaction of 1,2-phenylenediamine yielded quinoxaline-annulated [2.1.2.1]MCP 5 . The UV and fluorescence spectra as well as the influences of an alkali metal ion on the fluorescence spectra of quinoxaline-annulated [2.1.2.1]MCP 5 were reported

The Synthesis and Property of Dihydropyrene Derivatives Containing a Nitrogen Atom

Dihydropyrene (DHP) is 14π aromatic compound and applied as an aromatic probe by chemical shift of internal methyl groups in 1H-NMR spectra. DHP containing a nitrogen atom 1a and 2a were designed as photochromic compounds which were restrained thermal-isomerization. 1a and 2a were confirmed as DHP types by 1H-NMR spectra. Chemical shifts of internal methyl groups of 1a and 2a were observed at the lower magnetic field than that of DHP 3a . According to optimized structures of 1a and 3a , it was expected that the internal methyl group located of the out at center of 14π annulene ring. Isomerization to [2.2]metacyclophanediene 1b from DHP 1a by photo-irradiation of visible light was not observed.

Physicochemical properties of resorcinol-type calix[4]arenes phosphoric esters having four alkyl side chains in aqueous solution

The physicochemical properties of phosphate esters of resorcinol-type of calix[4]arenes([4]Ar5P-Rn; side chain length n=6, 8, and 12) in aqueous solutions have been characterized by several techniques including surface tension and NMR. It is found that the critical micelle concentrations (cmcs) of [4]Ar5P-Rn are insensitive against the alkyl side chain length, whereas the polarity of aggregates remarkably depends on the alkyl side chain length. From static light scattering and NMR measurements it is suggested that the shapes of aggregates of [4]Ar5P-Rn are not globular and the alkyl side chains of [4]Ar5P-Rn gather loosely in the aggregates. The mixed properties of [4[Ar5P-R12 and hexaethyleneglycol dodecylether have also been investigated. The mixed cmcs are considerably greater than those of the respective surfactant cmcs and the interaction parameter calculated using a modified regular solution theory is +2.7. These results indicate that the repulsive interactions occur in the mixed micelles.

Stereoselective photosolvolyses of ipso-acetoxynitro-adducts of p-xylene

Abstract Diastereoisomers of 1,4-dimethyl-4-nitro-2,5-cyclohexadienyl acetate exchanged acetoxyls for alkoxyls on irradiation in alcohols to give the diastereoisomers of alkyl, 1,4-dimethyl-4-nitro-2,5-cyclohexadienyl ethers in isomer ratios of 70:30, whereas the irradiation in pentane yielded p -xylene.

Grignard reactions of ipso-methoxynitro-adducts of p-xylene

Grignard reactions of the ipso-methoxynitro-adducts (1a) and (1b) yielded the hydroxylamines (2) and (3) whose configurations were determined by i.r. spectroscopy.

Studies of collectors. Part 12. The flotation of gallium ion with polyphenol-type surfactants

Polyphenol-type surfactants bearing 1,2-benzenediol or 1,2,3-trihydroxybenzene units were prepared and applied as flotation collectors for Ga3+. The surfactants exhibited a lowering of surface tension at pH 11 (32–47 dyn cm–1. Gallium(III) was highly floated (80–90%) at pH 3–8 with equimolar Cn– 1H2n– 1C(O)C6H3(OH)2(n= 8 or 12) or C7H15C(O)C6H2(OH)3, but not as highly (60%) with C12H25S[CH2CHC(O)C6H3(OH)2]4.8(CH2CHCO2H)9.5H. The floatabilities of Ga3+ in 1 mol dm–3 NaOH were 86–99%, those in 3 mol dm–3 NaOH were 63–67%, and those in 5 mol dm–3 NaOH were 26–39% by using a six-fold molar excess of Cn– 1H2n– 1C(O)C6H3(OH)2(n= 12 or 18). On the other hand, the floatabilities from 1–5 mol dm–3 NaOH solutions when Cn– 1H2n– 1C(O)C6H2(OH)3 was added were nearly constant (58–59% with n= 12 and 31–35% with n= 18). The Ga3+ in a Ga3+–Al3+ mixture was floated selectively at pH 3–5 by using C7H15C(O)C6H3(OH)2 or C7H15C(O)C6H2(OH)3. Moreover, the polyphenol-type surfactants in these flotation systems were almost entirely absent (<10–5 mol dm–3) from 3–5 mol dm–3 NaOH solutions and little decomposed.