Papers - Higashibayashi, Shuhei

Synthesis of flake-shaped [3]cyclo-4,6-benzofuranylene

Shuhei Higashibayashi

CHEMISTRY LETTERS 47 ( 1 ) 95 - 96 2018

Research paper (scientific journal), Joint Work, Accepted,  ISSN  03667022

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© 2018 The Chemical Society of Japan. The cyclic trimer of dibenzofuran linked at the 4,6-positions, named [3]cyclo-4,6-dibenzofuranylene, was synthesized by Ni(0)-mediated reductive coupling of 4,6-dibromodibenzofuran. DFT calculation indicated that the flake-shaped C2 symmetric structure is the most stable conformer and the propeller-shaped D3 symmetric structure is the minor conformer with a higher energy (+19.1 kcal mol-1). The calculated inversion energy of the C2 conformer through a Cs symmetric transition state was +4.1 kcal mol-1, showing rapid fluctuation, which is consistent with the observation of only one set of 1HNMR signals of dibenzofuran of [3]cyclo-4,6-dibenzofuranylene.

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Tris(2-hydroxyphenyl)triazasumanene: bowlshaped excited-state intramolecular proton transfer (ESIPT) fluorophore coupled with aggregation-induced enhanced emission (AIEE)

Patcharin Kaewmati, Yumi Yakiyama, Hiroyoshi Ohtsu, Masaki Kawano, Setsiri Haesuwannakij, Shuhei Higashibayashi, Hidehiro Sakurai

MATERIALS CHEMISTRY FRONTIERS 2 ( 3 ) 514 - 519 2018

Research paper (scientific journal), Joint Work, Accepted

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© 2018 Royal Society of Chemistry. All rights reserved. Tris(2-hydroxyphenyl)triazasumanene ((A)-(+)-1), a bowl-shaped molecule, which possesses 2-(20-hydroxyphenyl)pyridine moieties, was successfully synthesised. (A)-(+)-1 showed a single peak emission in CH2Cl2, which overlapped with the emission of the triazasumanene skeleton and diminished at a high concentration, corresponding to the formation of the excited enol form. In contrast, single crystals of (A)-(+)-1 exhibited a dual emission with a large Stokes shift, indicating the presence of the excited keto form by the excited state intramolecular proton transfer (ESIPT) process. In the solution of (A)-(+)-1 containing a mixture of a large amount of a poor solvent (hexane or MeOH) and a small amount of CH2Cl2, colloidal aggregates emerged with the continuous increment of emission intensity by further addition of the poor solvent, demonstrating aggregation-induced enhanced emission (AIEE). The analysis of the morphology and the structure of the aggregates using a scanning electron microscope (SEM) and powder X-ray diffraction (PXRD) revealed the well-ordered structure of the aggregates, which possessed a molecular packing pattern similar to that of an (A)-(+)-1 single crystal.

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Synthesis of fisetin and 2,4,6-trihydroxydihyrochalcone 4-O--neohesperidoside based on site-selective deacetylation and deoxygenation

Tsunekawa, Ryuji, Hanaya, Kengo, Higashibayashi, Shuhei, Sugai, Takeshi

BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY 82 ( 8 ) 1316 - 1322 2018

Research paper (scientific journal), Joint Work, Accepted,  ISSN  0916-8451

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© 2018 Japan society for Bioscience, Biotechnology, and Agrochemistry. Fisetin and 2′,4′,6′-trihydroxydihyrochalcone 4′-O-β-neohesperidoside were synthesized from commercially available quercetin and naringin in five steps. The key steps are site-selective deacetylation and subsequent deoxygenation. The target molecules were obtained in 37% and 23% yields from the starting materials, respectively.

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Synthesis of oroxylin A starting from naturally abundant baicalin

Fujita, Rie, Hanaya, Kengo, Higashibayashi, Shuhei, Sugai, Takeshi

HETEROCYCLES 97 ( 2 ) 1165 - 1174 2018

Research paper (scientific journal), Joint Work, Accepted,  ISSN  03855414

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© 2018 The Japan Institute of Heterocyclic Chemistry – A new approach to oroxylin A, a monomethylated trihydroxyflavone, is described. The starting material was baicalin, a representative naturally abundant flavonoid glucuronide. First, conditions for the cleavage of the glycosidic bond were established, using a mixture of water and conc. sulfuric acid (5:2) at 121 °C for 40 min. The hydrolysis was performed in a high-pressure steam sterilizer so that the temperature and reaction time were precisely controlled. Subsequent acetylation of the crude material furnished baicalein 6,7-diacetate on a preparative scale and in a reproducible manner. Next, the C-7 position was protected site-selectively with a methoxymethyl (MOM) group, taking advantage of an unexpected sequential migration of the two acetyl groups among the C-5, C-6, and C-7 positions under basic conditions. The removal of the two remaining acetyl groups followed by site-selective methylation of the C-6 position furnished 5-hydroxy-6-methoxy-7-methoxymethoxyflavone (oroxylin A C-7 MOM ether). Finally, by the deprotection of the MOM ether, oroxylin A was obtained in 6 total steps and 62% overall yield from baicalin.

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Synthesis of 3β-tert-Butyldimethylsiloxy-22-phenylthio-23,24-bisnorchola-5,9(11)-diene and Reductive Nucleophilic Attack on a Branched Aliphatic Aldehyde

Nagai T., Hanaya K., Higashibayashi S., Shoji M., Sugai T.

Chemical and Pharmaceutical Bulletin 66 ( 3 ) 334 - 338 2018

Research paper (scientific journal), Accepted,  ISSN  00092363

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3β-tert-Butyldimethylsiloxy-22-phenylthio-23,24-bisnorchola-5,9(11)-diene, which has a double bond between C-9 and C-11 and a phenylsulfenyl group on the terminus of the side chain, is a potential synthetic intermediate for steroids with 9,11-unsaturation or 9,11-seco skeletons. We describe here the synthesis of the title compound from 17-ethylenedioxy-3-acetoxyandrosta-3,5-dien-11-one. The introduction of an ethylene unit to 3β-tert-butyldimethylsiloxyandrosta-5,9(11)-dien-17-one by the action of ethyltriphenylphosphonium bromide under basic conditions resulted in an inseparable mixture of two stereoisomeric products (5 : 1). However, in the subsequent step, only the (Z)-isomer was susceptible to the Lewis acid-catalyzed ene reaction with formaldehyde, giving a stereochemically pure product with the desired configuration. Within three steps, the ene-product was derivatized to the title compound, with a total yield of 53% over seven steps. Reductive terminal anion formation by treatment with lithium di-tert-butylbiphenyl (LiDBB) and subsequent nucleophilic attack on a branched aliphatic aldehyde was demonstrated, with an eye toward the introduction of side chains, especially for steroids with oxygen functionality at C-23.

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Construction of 2,6,9,11-tetraoxatricyclo[6.2.1.0(3,8)]undecane containing 4-keto-D-glucose skeleton

Ban Fujitani, Kengo Hanaya, Shuhei Higashibayash, Mitsuru Shoji, Takeshi Sugai

TETRAHEDRON 73 ( 51 ) 7217 - 7222 2017.12

Research paper (scientific journal), Joint Work, Accepted,  ISSN  0040-4020

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Non-Planar [n]Cyclo-1,8-carbazolylenes (n=3,4,6) and [3]Cyclo-1,8-carbazolylenyl B, P, PO, SiPh Complexes

Koji Yamamoto, Palash Pandit, Shuhei Higashibayashi

CHEMISTRY-A EUROPEAN JOURNAL 23 ( 56 ) 14011 - 14016 2017.10

Research paper (scientific journal), Joint Work, Accepted,  ISSN  0947-6539

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Synthesis of the 1,2-seco fusicoccane diterpene skeleton by Stille coupling reaction between the highly functionalized A and C ring segments of cotylenin A

Kazuaki Kuwata, Kengo Hanaya, Shuhei Higashibayashi, Takeshi Sugai, Mitsuru Shoji

TETRAHEDRON 73 ( 41 ) 6039 - 6045 2017.10

Research paper (scientific journal), Joint Work, Accepted,  ISSN  0040-4020

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Synthesis of a C70 fragment buckybowl C28H14 from a C60 fragment sumanene

Shota Hishikawa, Yuki Okabe, Ryoji Tsuruoka, Shuhei Higashibayashi, Hiroyoshi Ohtsu, Masaki Kawano, Yumi Yakiyama, Hidehiro Sakurai

CHEMISTRY LETTERS 46   1556 - 1559 2017.07

Research paper (scientific journal), Joint Work, Accepted

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Synthesis of Triaryltriazasumanenes

Patcharin Kaewmati, Qitao Tan, Shuhei Higashibayashi, Yumi Yakiyama, Hidehiro Sakurai

CHEMISTRY LETTERS 46 ( 1 ) 146 - 148 2017.01

Research paper (scientific journal), Joint Work, Accepted,  ISSN  0366-7022

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Electronic and vibrational structures in the S-0 and S-1 states of coronene

Sachi Kunishige, Ayumi Kanaoka, Toshihar Katori, Megumi Kawabata, Masaki Baba, Takaya Yamanaka, Shuhei Higashibayashi, Hidehiro Sakurai

JOURNAL OF CHEMICAL PHYSICS 146 ( 4 ) 14011 - 14016 2017.01

Research paper (scientific journal), Joint Work, Accepted,  ISSN  0021-9606

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Sumanene derivatives functionalized at the internal carbon

Niti Ngamsomprasert, Jing-Shuang Dang, Shuhei Higashibayashi, Yumi Yakiyama, Hidehiro Sakurai

CHEMICAL COMMUNICATIONS 53 ( 4 ) 697 - 700 2017.01

Research paper (scientific journal), Joint Work, Accepted,  ISSN  1359-7345

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Elucidation of the fluorine substitution position on the phenyl ring of synthetic cannabinoids by electron ionization-triple quadrupole mass spectrometry

Takaya Murakami, Yoshiaki Iwamuro, Reiko Ishimaru, Satoshi Chinaka, Ippei Noda, Shuhei Higashibayashi, Nariaki Takayama

JAPANESE JOURNAL OF FORENSIC SCIENCE AND TECHNOLOGY 22   133 - 143 2017

Research paper (scientific journal), Joint Work, Accepted

Synthesis of Hydroxysumanene and Substituent Effect of Hydroxy Group on Bowl Inversion Dynamics and Electronic Structure

Niti Ngamsomprasert, Gautam Panda, Shuhei Higashibayashi, Hidehiro Sakurai

JOURNAL OF ORGANIC CHEMISTRY 81 ( 23 ) 11978 - 11981 2016.12

Research paper (scientific journal), Joint Work, Accepted,  ISSN  0022-3263

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Bowl Inversion and Electronic Switching of Buckybowls on Gold

Shintaro Fujii, Maxim Ziatdinov, Shuhei Higashibayashi, Hidehiro Sakurai, Manabu Kiguchi

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 138 ( 37 ) 12142 - 12149 2016.09

Research paper (scientific journal), Joint Work, Accepted,  ISSN  0002-7863

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Redox-Dependent Transformation of a Hydrazinobuckybowl between Curved and Planar Geometries

Shuhei Higashibayashi, Palash Pandit, Rie Haruki, Shin-ichi Adachi, Reiji Kumai

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION 55 ( 36 ) 10830 - 10834 2016.08

Research paper (scientific journal), Joint Work, Accepted,  ISSN  1433-7851

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Thermal stability, solubility, and fluorescence property of poly(arylene vinylene ketone)s bearing 1,1 '-binaphthylene units

Tadashi Tsukamoto, Katsuya Maeyama,　Shuhei Higashibayashi, Hidehiro Sakurai

REACTIVE & FUNCTIONAL POLYMERS 100   123 - 129 2016.03

Research paper (scientific journal), Joint Work, Accepted,  ISSN  1381-5148

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Synthesis of Three-Dimensional Butterfly Slit-Cyclobisazaanthracenes and Hydrazinobisanthenes through One-Step Cyclodimerization and Their Properties

Koji Yamamoto, Shuhei Higashibayashi

CHEMISTRY-A EUROPEAN JOURNAL 22 ( 2 ) 663 - 671 2016.01

Research paper (scientific journal), Joint Work, Accepted,  ISSN  0947-6539

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Synthesis and Characterization of Poly(arylene vinylene ketone)s Bearing 1,1 '-Binaphthylene Units through Mizoroki-Heck Coupling Polymerization

Tadashi Tsukamoto, Katsuya Maeyama,　Shuhei Higashibayashi, Hidehiro Sakurai

CHEMISTRY LETTERS 44 ( 12 ) 1780 - 1782 2015.12

Research paper (scientific journal), Joint Work, Accepted,  ISSN  0366-7022

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Synthesis of organosoluble and fluorescent aromatic polyketones bearing 1,1'-binaphthyl units through Suzuki-Miyaura coupling polymerization

Katsuya Maeyama,　Tadashi Tsukamoto, Hiroaki Kumagai, Shuhei Higashibayashi, Hidehiro Sakurai

POLYMER BULLETIN 72 ( 11 ) 2903 - 2916 2015.11

Research paper (scientific journal), Joint Work, Accepted,  ISSN  0170-0839

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