Papers - YAMAMURA Hatsuo
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Tautomerism between exomethylene type physalins and oxymethylene-bridged physalins Reviewed
B. Makino, Masao Kawai, H. Yamamura, S. Araki, Y. Butsugan
Pharmazie 57 ( 3 ) 215 - 216 2002
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Shuki ARAKI, Hiromi HATTORI, Koji OGAWA, Masashi KUZUYA, Tomoko INOUE, Hatsuo YAMAMURA, Masao KAWAI
J. Chem. Soc., Perkin Trans.1 2476 - 2482 2001.04
Publishing type：Research paper (scientific journal)
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Critical Difference in Chiral Recognition of N-Cbz-D/L-aspartic and -glutamic Acids by Mono- and Bis(trimethylammonio)-beta-cyclodextrins. Reviewed
Mikhail REKHARSKY, Hatsuo YAMAMURA, Masao KAWAI, Yoshihisa INOUE
J. Am. Chem. Soc. 123 5360 - 5361 2001.04
Publishing type：Research paper (scientific journal)
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Capillary Zone Eelectrophoretic Chiral Discrimination Using Cationic Cyclodextrin Dderivative. Determination of Velocity andAssociation Constants of Each Enantiomer of Amino Acid Derivative with 6-Trimethylammonio-deoxy-beta-cyclodextrin Reviewed
Hatsuo YAMAMURA, Asako AKASAKI, Yuichi YAMADA, Kazuaki KANO, Takao Katsuhara, Shuki ARAKI, Masao KAWAI, Takao TSUDA
Electrophoresis 22 478 - 483 2001.04
Publishing type：Research paper (scientific journal)
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Calorimetric and NMR Studies on the Direct Correlation between Supramolecular Complex Structure and the Thermodynamics ofN-Benzyloxycarbonyl-L-aspartic and -glutamic Acids Inclusion with Mono- and Bis(trimethylammonio)-beta-cyclodextrins Reviewed
Hatsuo YAMAMURA, Mikhail REKHARSKY, Asako AKASAKI, Shuki ARAKI, Masao KAWAI, Yoshihisa INOUE
J. Phys. Org. Chem. 14 416 - 424 2001.04
Publishing type：Research paper (scientific journal)
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Allylindation of Cyclopropenes in Organic and Aqueous Media:Switching the Regio- and Stereoselectivity Based on the Chelation with aHydroxy Group and the Crystal Structure of the Cyclopropylindium Product Reviewed
Shuki ARAKI, Fumio SHIRAKI, Takashi TANAKA, Hiroyuki NAKANO, Kandasamy Subburaj, Tsunehisa HIRASHITA, Hatsuo YAMAMURA, MasaoKAWAI
Chem. Eur. J. 7 ( 13 ) 2784 - 2790 2001.04
Publishing type：Research paper (scientific journal)
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Tsunehisa HIRASHITA, Hatsuo YAMAMURA, Masao KAWAI, Shuki ARAKI
Chem. Commun. 387 - 388 2001.04
Publishing type：Research paper (scientific journal)
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Zinc Bromide-Promoted Tosylation of Alcohols Allows Efficient Temperature-Controlled Primary Hydroxy Sulfonylation Reviewed
Hatsuo YAMAMURA, Jyumpei KAWASAKI, Hirokazu SAITO, Shuki ARAKI, Masao KAWAI
Chem. Lett 706 - 708 2001.04
Publishing type：Research paper (scientific journal)
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The Structure of Physalin T from Physalis Alkekengi var. Francheti. Reviewed
Masao KAWAI, Tatsuo YAMAMMOTO, Bunsho MAKINO, Hatsuo YAMAMURA, Shuki ARAKI, Yasuo BUTSUGAN, Kazuki SAITO
J. Asian Natural Products Research 3 199 - 205 2001.04
Publishing type：Research paper (scientific journal)
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A new cascade for the one-pot synthesis of linear homoallylic alcohols with an allylic diindium reagent Reviewed
T Hirashita, H Yamamura, M Kawai, S Araki
CHEMICAL COMMUNICATIONS ( 4 ) 387 - 388 2001
Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY
A new cascade based on a novel allylic diindium reagent has been developed; the indium reagent prepared from 3-bromo-1-iodopropene successively coupled with carbonyl compounds and then with aryl, alkenyl or allyl halides in the presence of a Pd(0) catalyst to afford a convenient one-pot synthesis of linear homoallylic alcohols.
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Zinc bromide-promoted tosylation of alcohols allows efficient temperature-controlled primary hydroxy sulfonylation Reviewed
Hatsuo Yamamura, Jyumpei Kawasaki, Hirokazu Saito, Shuki Araki, Masao Kawai
Chemistry Letters ( 7 ) 706 - 707 2001
Language：English Publishing type：Research paper (scientific journal) Publisher：Chemical Society of Japan
The combination of zinc bromide with tosyl chloride promoted sulfonylation, allowing temperature-controlled regioselective sulfonylation of carbohydrates which possess both primary and secondary hydroxy groups.
DOI： 10.1246/cl.2001.706
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The structure of physalin T from Physalis alkekengi var. francheti Reviewed
M Kawai, T Yamamoto, B Makino, H Yamamura, S Araki, Y Butsugan, K Saito
JOURNAL OF ASIAN NATURAL PRODUCTS RESEARCH 3 ( 3 ) 199 - 205 2001
Language：English Publishing type：Research paper (scientific journal) Publisher：HARWOOD ACAD PUBL GMBH
A new steroidal constituent named physalin T (3) was isolated from the aqueous extract of Physalis alkekengi var. francheti. Based on H-1 and C-13 NMR spectral studies the structure was assigned as 2,3-dihydrophysalin D, i.e., 5 alpha ,6 beta -dihydroxy-2,3,5,6-tetrahydrophysa B, which is the first example of a natural physalin possessing a saturated ring A moiety. The structure was confirmed by the chemical transformation from the known physalin D (2) to physalin T.
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The photochemical reactions of nitrogen-rich mesoionic 1,3-diphenyltetrazolium heterocycles and related compounds Reviewed
Shuki Araki, Hiromi Hattori, Koji Ogawa, Masashi Kuzuya, Tomoko Inoue, Hatsuo Yamamura, Masao Kawai
Journal of the Chemical Society. Perkin Transactions 1 1 ( 19 ) 2476 - 2482 2001
Language：English Publishing type：Research paper (scientific journal)
Photochemical reactions of azo and triazo derivatives of mesoionic 1,3-diphenyltetrazolium heterocycles and related compounds were studied. The reaction paths were found to depend markedly on the types of substrate, substituent and reaction solvent giving diverse products. Upon irradiation of the 1,1′3,3′-tetraphenylazoditetrazolium salt 1, the addition of hydrogen and acetone to the N-N bond was observed in methanol and acetone, respectively, whereas the bond was cleaved in diethyl ketone to give the 5-aminotetrazolium salt 10. The corresponding radical cation 11 also gave the reduction product in methanol. On the other hand, the 1,3-diphenyl-5-(phenylazo)tetrazolium salt 12 underwent nitrogen evolution giving the 1,3-diphenyltetrazolium salt 13 via the corresponding tetrazolium radical. Triazene derivatives 14 and 17 underwent an N–N bond cleavage to give tetrazolio-5-amide 4. The mesoionic triazene compounds bearing a tosyl 18 or cyano group 19 gave products 20 and 23. Triphenylphosphinotriazene 24 liberated nitrogen to give phosphinoimide 25 and its hydrolysis product 10. Tetrazolylamide 26 lost a phenyldiazonium group from the 1,3-diphenyltetrazolium ring to give the guanidine derivative 27. © 2001 The Royal Society of Chemistry.
DOI： 10.1039/b009526p
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Capillary zone electrophoretic chiral discrimination using a cationic cyclodextrin derivative: Determination of velocity and association constants of each enantiomer of the amino acid derivative with 6-trimethylammonio-deoxy-β-cyclodextrin Reviewed
Hatsuo Yamamura, Asako Akasaki, Yuichi Yamada, Kazuaki Kano, Takao Katsuhara, Shuki Araki, Masao Kawai, Takao Tsuda
Electrophoresis 22 ( 3 ) 478 - 483 2001
Language：English Publishing type：Research paper (scientific journal)
A positively charged β-cyclodextrin possessing a trimethylammonio group, 6-trimethylammonio-6-deoxy-β-cyclodextrin chloride 1 was prepared by the reaction of an amino derivative 3 with methyl iodide under very mild conditions. The cyclodextrin derivative discriminated between enantiomers of acetylphenylalanine 2 on capillary zone electrophoresis (CZE) analysis, which was possibly due to an electrostatic interaction between the trimethylammonio group of 1 and the carboxylate group of 2, and also due to the inclusion of 2 in a hydrophobic molecular cavity of 1. Double data normalization based on relative electrophoretic velocity of peaks due to indirect response of 1 and also water in an injected sample may be effective for elimination of variation and fluctuation of physical parameters of medium, such as viscosity and ionic strength, in order to determine intrinsic association constants and velocity of the complexes.
DOI： 10.1002/1522-2683(200102)22:3<478::AID-ELPS478>3.0.CO;2-L
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Calorimetric and NMR studies on the direct correlation between supramolecular complex structure and the thermodynamics of N-benzyloxycarbonyl-L-aspartic and -glutamic acid inclusion complexes with mono- and bis(trimethylammonio)-β-cyclodextrins Reviewed
Hatsuo Yamamura, Mikhail Rekharsky, Asako Akasaki, Schuki Araki, Masao Kawai, Yoshihisa Inoue
Journal of Physical Organic Chemistry 14 ( 7 ) 416 - 424 2001
Language：English Publishing type：Research paper (scientific journal)
The stability constants and standard Gibbs energy, enthalpy and entropy changes for the 1:1 inclusion complexation of N-benzyloxycarbonyl-L-aspartic and -glutamic acids with native β-cyclodextrin (β-CD), mono(6-amino-6-deoxy)-β-CD, mono(6-trimethylammonio-6-deoxy)-β-CD and A,B-, A,C- and A,D-bis(6-trimethylammonio-6-deoxy)-β-CDs were determined in aqueous phosphate buffer (pH 6.9) at 298.15 K by titration microcalorimetry. The supramolecular complex structures were elucidated from 1D and 2D NMR spectra, including ROESY, COSY and HOHAHA techniques. Combining the results obtained from the microcalorimetric and NMR studies, we elucidated not only the detailed complex structures and the thermodynamic consequences, but also the mutual dependence between the complex structure and the overall complexation thermodynamics. Copyright © 2001 John Wiley &
Sons, Ltd.DOI： 10.1002/poc.381
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Synthesis of New Tricyclic Mesoionic Amides via Photochemical Conversion of a 5-Azido-1-mesityl-3-phenyltetrazolium Salt Reviewed
Shuki ARAKI, Hiromi HATTORI, Hatsuo YAMAMURA, Masao KAWAI
J. Heterocyclic Chem. 37 1129 - 1134 2000.04
Publishing type：Research paper (scientific journal)
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Keiichi YAMADA, Yu-ichi TAKAHASHI, Hatsuo YAMAMURA, Shuki ARAKI, Masao KAWAI
J. Chem. Soc., Chem. Commun 1315 - 1316 2000.04
Publishing type：Research paper (scientific journal)
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A New Preparative Method for Allylic Indium (III) Reagents by Reductive Transmetalation of p-Allylpalladium (II) with Indium (I) Salts Reviewed
Shuki ARAKI, Toshiya KAMEI, Tsunehisa HIRASHITA, Hatsuo YAMAMURA, Masao KAWAI
Organic Lett 2 847 - 849 2000.04
Publishing type：Research paper (scientific journal)
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A Facile Preparation of Indium Enolates and Their Reformatsky-and Darzens-type Reactions Reviewed
Tsunehisa HIRASHITA, Kenji KINOSHITA, Hatsuo YAMAMURA, Masao KAWAI, Shuki ARAKI
J. Chem. Soc., Perkin Trans 1 825 - 828 2000.04
Publishing type：Research paper (scientific journal)
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A facile preparation of indium enolates and their Reformatsky- and Darzens-type reactions Reviewed
T Hirashita, K Kinoshita, H Yamamura, M Kawai, S Araki
JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 1 ( 5 ) 825 - 828 2000
Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY
Indium enolates were readily prepared by transmetalation of lithium enolates with indium trichloride, and were subsequently reacted with aldehydes to give beta-hydroxy esters in high yields. Indium alpha-bromo enolates were also prepared and reacted with carbonyl compounds to give Darzens-type alpha,beta-epoxy carbonyl products.
