Updated on 2024/05/18

写真a

 
TAYAMA Eiji
 
Organization
Academic Assembly Institute of Science and Technology Fundamental Sciences Associate Professor
Graduate School of Science and Technology Fundamental Sciences Associate Professor
Faculty of Science Department of Science Associate Professor
Title
Associate Professor
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External link

Degree

  • 理学博士「化学」 ( 2002.3   北海道大学 )

  • 理学修士「化学」 ( 1999.3   北海道大学 )

Research Interests

  • ylide

  • carbanion

  • tetraalkylammonium salt

  • rearrangement

  • elimination

Research Areas

  • Life Science / Bioorganic chemistry  / synthetic organic chemistry

  • Nanotechnology/Materials / Structural organic chemistry and physical organic chemistry  / synthetic organic chemistry

Research History (researchmap)

  • Faculty of Science, Niigata University   Associate Professor

    2008.8

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  • Guraduate School of Science and Technology, Niigata University   Assistant Professor

    2003.10 - 2008.7

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Research History

  • Niigata University   Faculty of Science Department of Science   Associate Professor

    2017.4

  • Niigata University   Graduate School of Science and Technology Fundamental Sciences   Associate Professor

    2010.4

  • Niigata University   Graduate School of Science and Technology Fundamental Sciences   Associate Professor

    2010.4

  • Niigata University   Abolition organization Organic and Biological Chemistry   Associate Professor

    2008.8 - 2017.3

  • Niigata University   Graduate School of Science and Technology Fundamental Sciences Chemistry   Assistant Professor

    2007.4 - 2008.7

  • Niigata University   Graduate School of Science and Technology Fundamental Sciences Chemistry   Research Assistant

    2004.4 - 2007.3

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Professional Memberships

  • American Chemical Society

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  • THE SOCIETY OF SYNTHETIC ORGANIC CHEMISTRY, JAPAN

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Studying abroad experiences

  • トロント大学・化学科(Toronto University),カナダ   博士研究員

    2002.6 - 2003.9

 

Papers

  • Nitrogen- and Sulfur-Based Stevens and Related Rearrangements Invited Reviewed

    Eiji Tayama

    Comprehensive Organic Synthesis, 3rd Edition ( Pre-released in Reference Module in Chemistry, Molecular Sciences and Chemical Engineering)   2024.1

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    Authorship:Lead author, Corresponding author   Language:English   Publishing type:Part of collection (book)  

    DOI: 10.1016/B978-0-323-96025-0.00029-6

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  • Synthesis of α-fluoro-γ-aminobutyric acid derivatives by nucleophilic ring-opening of azetidine-2-carboxylic acid-derived ammonium salts with fluoride Reviewed

    Eiji Tayama, Yutaro Kurosaki, Maho Iida, Takuya Aida, Nobuhiro Nakanome

    Tetrahedron   142   133528   2023.6

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    Authorship:Lead author, Corresponding author   Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1016/j.tet.2023.133528

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  • Recent Advances in the Generation of Onium Ylides for Sommelet–Hauser Rearrangements Invited Reviewed

    Eiji Tayama

    Synthesis   54   5385 - 5399   2022.8

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    Authorship:Lead author, Corresponding author   Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1055/a-1914-7261

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  • Chiral tetraalkynylborate as a chiral solvating agent for N-chiral tetraalkylammonium salts Reviewed

    Eiji Tayama, Ryotaro Nishio

    Tetrahedron   114   132783 - 132783   2022.4

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    Authorship:Lead author, Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:Elsevier {BV}  

    DOI: 10.1016/j.tet.2022.132783

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  • Base-induced Sommelet–Hauser rearrangement of N-(pyridinylmethyl) tetraalkylammonium salts Reviewed

    Eiji Tayama, Goshu Shimizu, Ryo Nakao

    Tetrahedron   111   132721 - 132721   2022.3

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    Authorship:Lead author, Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:Elsevier {BV}  

    DOI: 10.1016/j.tet.2022.132721

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  • Synthesis of tertiary alkyl fluorides and chlorides by site-selective nucleophilic ring-opening reaction of α-aryl azetidinium salts Reviewed

    Eiji Tayama, Kohei Kawai

    RSC Advances   11 ( 62 )   39607 - 39618   2021.12

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    Authorship:Lead author, Corresponding author   Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1039/D1RA08706A

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  • Synthesis of optically active 2-substituted azetidine-2-carbonitriles from chiral 1-arylethylamine via α-alkylation of N-borane complexes Reviewed

    Eiji Tayama, Nobuhiro Nakanome

    RSC Advances   11 ( 38 )   23825 - 23837   2021.7

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    Authorship:Lead author, Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:Royal Society of Chemistry (RSC)  

    <p>Synthesis of optically active 2-substituted azetidine-2-carbonitriles by LDA-promoted diastereoselective α-alkylation of borane <italic>N</italic>-((<italic>S</italic>)-1-arylethyl)azetidine-2-carbonitrile complexes was demonstrated.</p>

    DOI: 10.1039/d1ra04585g

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  • Brønsted Acid-Catalyzed Aza-Ferrier Reaction of N,O-Allenyl Acetals: Synthesis of β-Amino-α-methylene Aldehydes Reviewed

    Eiji Tayama, Yuki Ishikawa

    The Journal of Organic Chemistry   85 ( 14 )   9405 - 9414   2020.7

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    Authorship:Lead author, Corresponding author   Publishing type:Research paper (scientific journal)   Publisher:American Chemical Society (ACS)  

    DOI: 10.1021/acs.joc.0c01047

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  • Base-induced Sommelet–Hauser rearrangement of N-(α-(2-oxyethyl)branched)benzylic glycine ester-derived ammonium salts via a chelated intermediate Reviewed

    Eiji Tayama, Kazuki Hirano, Souya Baba

    Tetrahedron   76 ( 14 )   131064 - 131064   2020.2

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    Authorship:Lead author, Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:Elsevier BV  

    DOI: 10.1016/j.tet.2020.131064

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  • Chiral Tetraaryl- and Tetraalkynylborates as Chiral Solvating Agents for Tetraalkylammonium Salts Reviewed

    Eiji Tayama, Takeshi Sugawara

    European Journal of Organic Chemistry   803 - 811   2018.12

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    Authorship:Lead author, Corresponding author   Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1002/ejoc.201801448

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  • Base-promoted Aromatic [3,3] Sigmatropic Rearrangement of N-Acyl-O-arylhydroxylamine Derivatives Reviewed

    Eiji Tayama, Kazuki Hirano

    Tetrahedron   75 ( 5 )   665 - 673   2018.12

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    Authorship:Lead author, Corresponding author   Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1016/j.tet.2018.12.058

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  • Base-promoted diastereoselective α-alkylation of borane N-((S)-1′-phenylethyl)azetidine-2-carboxylic acid ester complexes Reviewed

    Eiji Tayama, Ryotaro Nishio, Yoshiaki Kobayashi

    Organic & Biomolecular Chemistry   16 ( 32 )   5833 - 5845   2018.7

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    Authorship:Lead author, Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:Royal Society of Chemistry ({RSC})  

    DOI: 10.1039/c8ob01395k

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  • Dearomative [2,3] sigmatropic rearrangement of ammonium ylides followed by 1,4-elimination to form α-(ortho-vinylphenyl)amino acid esters Reviewed

    Eiji Tayama, Sho Sotome

    Organic & Biomolecular Chemistry   16 ( 32 )   4833 - 4839   2018.6

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    Authorship:Lead author, Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:Royal Society of Chemistry ({RSC})  

    DOI: 10.1039/c8ob01091a

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  • Structural and mechanistic studies of the base-induced Sommelet-Hauser rearrangement of N-alpha-branched benzylic azetidine-2-carboxylic acid-derived ammonium salts Reviewed

    Eiji Tayama, Kazutoshi Watanabe, Sho Sotome

    ORGANIC & BIOMOLECULAR CHEMISTRY   15 ( 31 )   6668 - 6678   2017.8

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    Authorship:Lead author, Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:ROYAL SOC CHEMISTRY  

    The base-induced Sommelet-Hauser rearrangement of N-alpha-branched benzylic azetidine-2-carboxylic acid ester-derived ammonium salts to obtain a-arylazetidine-2-carboxylic acid esters was investigated. The substrates, two diastereomeric salts (1S,2S,1'S)-and (1R,2R,1' S)-2, showed different reactivities. The rearrangement of (1S,2S,1'S)-2a proceeded with a perfect N-to-C chirality transfer to provide (R)-3a in 74% yield with 99% ee. However, the rearrangement of (1R,2R,1'S)-2a under the same conditions afforded (S)-3a in only 15% yield with a lower 66% ee, along with the competitive [1,2] Stevens rearrangement product 4a. Structural and mechanistic studies of this rearrangement were carried out to clarify the exact reason. Our results define the scope and limitations of the Sommelet-Hauser rearrangement and provide unique synthetic access to alpha-aryl amino acid derivatives.

    DOI: 10.1039/c7ob01391d

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    Other Link: http://orcid.org/0000-0002-0309-9507

  • Ring-Strain Effects in Base-Induced Sommelet-Hauser Rearrangement: Application to Successive Stereocontrolled Transformations Reviewed

    Eiji Tayama, Kazutoshi Watanabe, Yoshihiro Matano

    EUROPEAN JOURNAL OF ORGANIC CHEMISTRY   2016 ( 21 )   3631 - 3641   2016.7

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    Authorship:Lead author, Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:WILEY-V C H VERLAG GMBH  

    The base-induced Sommelet-Hauser (S-H) rearrangement of azetidine-2-carboxylic acid ester-derived ammonium salts into 2-aryl-substituted derivatives was demonstrated. The ring-strain of four-membered N-heterocycles enables efficient generation of the desired ylide intermediate and enhances the rate of the S-H rearrangement. The asymmetric version of the rearrangement was characterized by excellent levels of successive chirality transmissions. The regio- and stereo-controlled nucleophilic ring opening of the rearrangement products produced quaternary -aryl amino acid esters with excellent enantiopurities.

    DOI: 10.1002/ejoc.201600611

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  • RING-SUBSTITUTION, ENLARGEMENT, AND CONTRACTION BY BASE-INDUCED REARRANGEMENTS OF N-HETEROCYCLIC AMMONIUM SALTS Invited Reviewed

    Eiji Tayama

    HETEROCYCLES   92 ( 5 )   793 - 828   2016.5

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    Authorship:Lead author, Corresponding author   Language:English   Publisher:PERGAMON-ELSEVIER SCIENCE LTD  

    An overview of the utility of base-induced Stevens, Sommelet-Hauser, and related sigmatropic rearrangements of N-heterocyclic ammonium salts into various types of N-heterocycles reported after 1970 will be described. The synthetic transformations are classified as N-heterocyclic ring-substitution, ring-enlargement, and ring-contraction.

    DOI: 10.3987/REV-16-837

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  • Solvent-Dependent Reaction Pathways Operating in Copper(II) Tetrafluoroborate Promoted Oxidative Ring-Opening Reactions of Cyclopropyl Silyl Ethers Reviewed

    Eietsu Hasegawa, Kazuki Nemoto, Ryosuke Nagumo, Eiji Tayama, Hajime Iwamoto

    JOURNAL OF ORGANIC CHEMISTRY   81 ( 7 )   2692 - 2703   2016.4

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:AMER CHEMICAL SOC  

    Oxidative ring-opening reactions of benzene-fused bicyclic cydopropyl silyl ethers, promoted by copper(II) tetrafluoroborate, were investigated. The regioselectivity of cyclopropane ring-opening as well as product distributions were found to be highly dependent on the nature of the solvent. In alcohols, dimeric substances arising from external bond cleavage are major products. Radical rearrangement products are also formed in solvents such as ether and ethyl acetate. On the contrary, nucleophile addition to carbocation intermediates, generated by internal bond cleavage, occurs mainly in reactions taking place in acetonitrile. It is proposed that the observed solvent effects that govern the reaction pathways followed are a consequence of varying solvation of copper intermediates, which governs their reactivity and redox properties. In addition, the influence of counteranions of the copper salts, organonitriles, cyclic dienes, and substrate structures on the pathways followed in these reactions was also examined.

    DOI: 10.1021/acs.joc.5b02827

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    Other Link: http://orcid.org/0000-0002-0309-9507

  • Regioselective synthesis of secondary 1,3-dienamides by successive eliminations Reviewed

    Eiji Tayama, Shun Saito

    TETRAHEDRON   72 ( 5 )   599 - 604   2016.2

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    The regioselective synthesis of secondary 1,3-dienamides 3 (1-N-acylamino-1,3-dienes) is successfully demonstrated by regiospecific base -promoted 1,4 -elimination of (Z)- or (E)-N,N-di-Boc-4-methoxy-2-buten-1 -ylamine 1 followed by mono-Boc elimination in situ. (C) 2015 Elsevier Ltd. All rights reserved,

    DOI: 10.1016/j.tet.2015.11.065

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  • Synthesis of linear [5]catenanes via olefin metathesis dimerization of pseudorotaxanes composed of a [2]catenane and a secondary ammonium salt Reviewed

    Hajime Iwamoto, Shinji Tafuku, Yoshihiko Sato, Wataru Takizawa, Wataru Katagiri, Eiji Tayama, Eietsu Hasegawa, Yoshimasa Fukazawa, Takeharu Haino

    CHEMICAL COMMUNICATIONS   52 ( 2 )   319 - 322   2016

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ROYAL SOC CHEMISTRY  

    [5]Catenanes were synthesized by olefin metathesis dimerization. The reaction of pseudorotaxanes, which were derived from a [2]catenane and one equivalent of an ammonium salt bearing two terminal olefins in dichloromethane, with a catalytic amount of Grubbs catalyst afforded linear [5]catenanes in 12% yield. Intermolecular and intramolecular olefin metathesis reactions were controlled by the length of the alkyl chain of the ammonium salts.

    DOI: 10.1039/c5cc07562a

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    Other Link: http://orcid.org/0000-0002-0309-9507

  • Diaza [1,4] Wittig-type rearrangement of N-allylic-N-Boc-hydrazines into gamma-amino-N-Boc-enamines Reviewed

    Eiji Tayama, Yoshiaki Kobayashi, Yuka Toma

    CHEMICAL COMMUNICATIONS   52 ( 69 )   10570 - 10573   2016

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    Authorship:Lead author, Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:ROYAL SOC CHEMISTRY  

    Diaza [1,4] Wittig-type rearrangement of N-allylic-N-Boc-hydrazines into gamma-amino-N-Boc-enamines was demonstrated. The scope and limitation, experimental mechanistic studies, and a proposed reaction mechanism were also described.

    DOI: 10.1039/c6cc04626f

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    Other Link: http://orcid.org/0000-0002-0309-9507

  • Copper-Catalyzed Regiospecific and 1,2-Regioselective Cyclopropanation of (1Z)-1-Amino- and (1Z)-1-Oxy-1,3-butadienyl Derivatives Reviewed

    Eiji Tayama, Shun Saito

    SYNLETT   26 ( 13 )   1880 - 1884   2015.8

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    Authorship:Lead author, Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:GEORG THIEME VERLAG KG  

    The copper-catalyzed regiospecific and 1,2-regioselective cyclopropanation of (1Z)-1-amino- and (1Z)-1-oxy-1,3-butadienyl derivatives, which could be prepared by Z-stereoselective 1,4-elimination with a-aryl diazoesters was successfully demonstrated. This successful regiospecific protocol enabled the preparation of the corresponding 1-amino- and 1-oxy-2-vinylcyclopropane derivatives as almost single stereoisomers.

    DOI: 10.1055/s-0034-1380426

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  • Aryl-substituted dimethylbenzimidazolines as effective reductants of photoinduced electron transfer reactions Reviewed

    Eietsu Hasegawa, Taku Ohta, Shiori Tsuji, Kazuma Mori, Ken Uchida, Tomoaki Miura, Tadaaki Ikoma, Eiji Tayama, Hajime Iwamoto, Shin-ya Takizawa, Shigeru Murata

    TETRAHEDRON   71 ( 34 )   5494 - 5505   2015.8

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:PERGAMON-ELSEVIER SCIENCE LTD  

    Photoinduced electron transfer (PET) reactions promoted by 2-aryl substituted 1,3-dimethylbenzimidazolines (Ar-DMBIH) were investigated. Excited states of Ar-DMBIH, formed by irradiation using light above 360 initiate PET reductions of various organic substrates, including transformations of epoxy ketones to aldols, free radical rearrangements such as the Dowd-Beckwith ring-expansion and 5-exo hexenyl cyclization, deprotection of N-sulfonyl-indols, and allylation of acyl formates. In these processes, Ar-DMBIH possessing 1-naphthyl, 2-naphthyl, 1-pyrenyl and 9-anthryl substituents formally act as two electron and one proton donors while the hydroxynaphthyl substituted derivative serves as a two electron and two proton donor. On the basis of the results of absorption spectroscopy studies, cyclic voltammetry and DFT calculation, a mechanistic sequence for these reduction reactions is proposed that involves initial photoexcitation of the aryl chromophore of the Ar-DMBIH followed by single electron transfer (SET) to the organic substrate to generate the radical cation of benzimidazoline and the radical anion of the substrate. (C) 2015 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.tet.2015.06.071

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  • Recent Advances in the Base-Induced Sommelet-Hauser Rearrangement of Amino Acid Derived Ammonium Ylides Invited Reviewed

    Eiji Tayama

    CHEMICAL RECORD   15 ( 4 )   789 - 800   2015.8

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    Authorship:Lead author, Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:WILEY-V C H VERLAG GMBH  

    The Sommelet-Hauser rearrangement of N-benzylic ammonium ylides generated from ammonium salts is an interesting and useful transformation that enables one to convert a readily accessible C-N bond into a new C-C bond to an aromatic ring. The rearrangement was discovered by Sommelet in 1937, studied in detail by Hauser, and applied to organic synthesis by Sato until 1999. Further studies have not advanced because several competitive side reactions and structural limitations of the products severely limit the substrate scope and synthetic applications. In this Personal Account, a history of the research in problem solving and recent advances in the base-induced Sommelet-Hauser rearrangement are described. This synthetic method developed by my group provides efficient access to various types of -aryl--amino acid and -aryl--amino acid derivatives.

    DOI: 10.1002/tcr.201500009

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    Other Link: http://orcid.org/0000-0002-0309-9507

  • Metal-Free, One-Pot, Sequential Protocol for-Transforming alpha,beta-Epoxy Ketones to beta-Hydroxy Ketones and alpha-Methylene Ketones Reviewed

    Eietsu Hasegawa, Saki Arai, Eiji Tayama, Hajime Iwamoto

    JOURNAL OF ORGANIC CHEMISTRY   80 ( 3 )   1593 - 1600   2015.2

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:AMER CHEMICAL SOC  

    A new sequential, one-pot protocol for transforming 1,3-disubstituted 2,3-epoxy ketones to beta-hydroxy ketones and alpha-methylene ketones has been developed. Reaction of epoxy ketones with boron trifluoride etherate ((BF3OEt2)-O-.) generates the cationic intermediates by regioselective epoxide ring opening and an acyl shift. Then, a treatment of these cations with 2-aryl-1,3-dimethylbenzimidazolines (DMBIH) results in formation of 1,2-disubstituted 3-hydroxy ketones. DMBIH serves as a hydride donor in the second step of this process. Finally, the beta-hydroxy ketones can be converted to 1,2-disubstituted 2-methylene ketones by treatment with methanesulfonic acid or a combination of methanesulfonyl chloride and triethylamine. Importantly, the sequential steps involved in formation of the alpha-methylene ketone products can be carried out in one pot.

    DOI: 10.1021/jo5025249

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    Other Link: http://orcid.org/0000-0002-0309-9507

  • Stereoselective preparation of (1Z)- and (1E)-N-Boc-1-amino-1,3-dienes by stereospecific base-promoted 1,4-elimination Reviewed

    Eiji Tayama, Yuka Toma

    TETRAHEDRON   71 ( 4 )   554 - 559   2015.1

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:PERGAMON-ELSEVIER SCIENCE LTD  

    The base-promoted 1,4-elimination reaction of N-Boc-1-amino-4-methoxy-2-alkene 1 is shown to proceed with perfect stereoselectivity to afford the corresponding N-Boc-1-amino-1,3-diene 2 in good yields. The reaction is highly stereospecific. The substrate E-1 gave 1Z-2 by the 'Syn-Effect' and Z-1 gave 1E-2 via formation of a chelated intermediate. Our method is widely applicable to the preparation of various types of N-Boc-1-amino-1,3-dienes 2. (C) 2014 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.tet.2014.12.039

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  • Copper(II)-acid catalyzed cyclopropanation of 1,3-dienamides by electrophilic activation of alpha-aryl diazoesters Reviewed

    Eiji Tayama, Kouki Horikawa, Hajime Iwamoto, Eietsu Hasegawa

    TETRAHEDRON LETTERS   55 ( 19 )   3041 - 3044   2014.5

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:PERGAMON-ELSEVIER SCIENCE LTD  

    Copper(II)-acid catalyzed cyclopropanation of electron-rich alkenes, such as 1,3-dienamides, with cc-aryl diazoesters are described. The reaction could be performed without rare metal catalysts, excess substrate, or the need for the slow addition of the diazoesters. (C) 2014 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.tetlet.2014.03.115

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  • New Development of Base-Induced Sommelet-Hauser Rearrangement of Ammonium Ylides Invited Reviewed

    Eiji d Tayama

    JOURNAL OF SYNTHETIC ORGANIC CHEMISTRY JAPAN   72 ( 4 )   418 - 428   2014.4

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    Authorship:Lead author, Corresponding author   Language:Japanese   Publishing type:Research paper (scientific journal)   Publisher:SOC SYNTHETIC ORGANIC CHEM JPN  

    The Sommelet-Hauser rearrangement of N-benzylic ammonium ylides generated from tetraal-kylammonium salts is an interesting and useful transformation in organic synthesis that can provide easy access to ortho-substituted aromatic compounds. The base-induced rearrangement of an N-chiral-N-benzylic proline-derived ammonium salt or N-benzylic amino acid (-)-8-phenylmenthol ester-derived ammonium salts is shown to proceed in excellent yields with perfect levels of diastereoselectivity without any detectable amount of the [1,2] Stevens rearrangement product. A solution of potassium tert-butoxide in THF was shown to remarkably enhance the base-induced Sommelet-Hauser rearrangement of N-benzylic amino acid-derived ammonium salts. The reaction proceeds under mild conditions with minimal competition from the [1,2]-Stevens rearrangement. These methods provide efficient access to alpha-aryl-alpha-amino acid, alpha-aryl-beta-amino acid, and alpha-arylpipecolinic acid derivatives.

    DOI: 10.5059/yukigoseikyokaishi.72.418

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  • A photo-reagent system of benzimidazoline and Ru(bpy)(3)Cl-2 to promote hexenyl radical cyclization and Dowd-Beckwith ringexpansion of alpha-halomethyl-substituted benzocyclic 1-alkanones Reviewed

    Eietsu Hasegawa, Minami Tateyama, Tsuneaki Hoshi, Taku Ohta, Eiji Tayama, Hajime Iwamoto, Shin-ya Takizawa, Shigeru Murata

    TETRAHEDRON   70 ( 17 )   2776 - 2783   2014.4

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:PERGAMON-ELSEVIER SCIENCE LTD  

    A combination of 2-aryl substituted 1,3-dimethyl-benzimidazolines (DMBIHs) and tris(2,2'-bipyridine) ruthenium(II) chloride, Ru(bpy)(3)Cl-2 was used to promote photoinduced electron-transfer (PET) reactions of alpha-halomethyl-substituted benzocyclic 1-alkanones. This photo-reagent system stimulates free radical forming, cleavage of both carbon-bromine and carbon-chlorine bonds that are not activated by carbonyl groups. The resulting free radicals undergo 5-exo hexenyl cyclization as well as sequential cyclization and ring-expansion (Dowd-Beckwith) reactions to form radicals that abstract hydrogen atoms from the radical cation of DMBIH to yield the observed products. The results of a study of the effects of substituents located on the 2-aryl ring of DMBIH suggest that steric and hydrogen-bonding interactions influence the nature of the reaction pathways followed by the radical intermediates. PET reactions using an iridium complex and DMBIH were also investigated. (C) 2014 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.tet.2014.02.078

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  • Double axial chirality promoted asymmetric [2,3] Stevens rearrangement of N-cinnamyl L-alanine amide-derived ammonium ylides Reviewed

    Eiji Tayama, Noriko Naganuma, Hajime Iwamoto, Eietsu Hasegawa

    CHEMICAL COMMUNICATIONS   50 ( 52 )   6860 - 6862   2014

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ROYAL SOC CHEMISTRY  

    The base-induced asymmetric [2,3] Stevens rearrangement of N-cinnamyl tetraalkylammonium ylides derived from L-alanine amides proceeds via a double axially chiral intermediate to afford the corresponding alpha-substituted alanine derivatives with high enantio-and diastereoselectivities.

    DOI: 10.1039/c4cc02536a

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  • Carbon-carbon bond formation via benzoyl umpolung attained by photoinduced electron-transfer with benzimidazolines Reviewed

    Tomohito Igarashi, Eiji Tayama, Hajime Iwamoto, Eietsu Hasegawa

    TETRAHEDRON LETTERS   54 ( 50 )   6874 - 6877   2013.12

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:PERGAMON-ELSEVIER SCIENCE LTD  

    A photoreaction between benzoyl compounds, such as benzoylformate derivatives, and 2-(p-anisyl)-1,3-dimethylbenzimidazoline in the presence of allyl bromide was found to give various allylated alcohols. In the reaction of benzoylformates, cc-hydroxy ester enolates, for which the negative charge occurs on the carbonyl carbon of benzoyl (umpolung reactivity), are proposed to be generated as intermediates by electron-transfer from benzimidazolines to the photoexcited benzoylformates; these species react with allyl bromide to produce alpha-allyl-alpha-hydroxy esters. (C) 2013 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.tetlet.2013.10.028

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  • Copper(II)-salt-promoted oxidative ring-opening reactions of bicyclic cyclopropanol derivatives via radical pathways Reviewed

    Eietsu Hasegawa, Minami Tateyama, Ryosuke Nagumo, Eiji Tayama, Hajime Iwamoto

    BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY   9   1397 - 1406   2013.7

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    Copper(II)-salt-promoted oxidative ring-opening reactions of bicyclic cyclopropanol derivatives were investigated. The regioselectivities of these processes were found to be influenced by the structure of cyclopropanols as well as the counter anion of the copper(II) salts. A mechanism involving rearrangement reactions of radical intermediates and their competitive trapping by copper ions is proposed.

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  • Selective Synthesis of [2]- and [3]Catenane Tuned by Ring Size and Concentration Reviewed

    Hajime Iwamoto, Wataru Takizawa, Koji Itoh, Tatsuya Hagiwara, Eiji Tayama, Eietsu Hasegawa, Takeharu Haino

    JOURNAL OF ORGANIC CHEMISTRY   78 ( 11 )   5205 - 5217   2013.6

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    The syntheses of [2]- and [3]catenanes by olefin metathesis and oxidative acetylide coupling have been studied in detail. Pseudorotaxanes that were obtained by mixing crown ether and ammonium salts containing two terminal reactive end-groups were converted to [2]- and [3]catenane. Their yields were influenced not only by the chain length of the ammonium salts but also by the concentration of the crown ether and the ammonium salts. The strain energies of [2]catenane were responsible for the formation of [2]catenane.

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  • 1,4-Elimination/Bronsted acid catalyzed aza-Ferrier reaction sequence as an entry to beta-amino-beta,gamma-unsaturated aldehydes Reviewed

    Eiji Tayama, Kouki Horikawa, Hajime Iwamoto, Eietsu Hasegawa

    TETRAHEDRON   69 ( 13 )   2745 - 2752   2013.4

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    The 1,4-elimination reaction of (Z)-N-Boc-2-(4-methoxy-2-alkenyloxy)amines with Bronsted acids catalyzed aza-Ferrier reaction of the 1,4-eliminated product, thus obtained, afforded various beta-amino-beta,gamma-unsaturated aldehydes. The scope and limitation of this sequential reaction are described. (C) 2013 Elsevier Ltd. All rights reserved.

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  • A UNIQUE AND SIMPLE PREPARATIVE METHOD FOR alpha-ARYLPIPECOLINIC ACID ESTERS VIA BASE-INDUCED SOMMELET-HAUSER REARRANGEMENT Reviewed

    Eiji Tayama, Ryota Sato, Motoshi Ito, Hajime Iwamoto, Eietsu Hasegawa

    HETEROCYCLES   87 ( 2 )   381 - 388   2013.2

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    A unique and simple preparative method for N-cyano-alpha-arylpipecolinic acid esters via base-induced Sommelet-Hauser rearrangement, the von Braun reaction, and intramolecular alpha-alkylation is reported. The removal of the N-cyano substituent was achieved by hydrogenation and hydride reduction.

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  • AN EFFECTIVE PROCEDURE TO PROMOTE AZA-PRINS CYCLIZATION REACTIONS EMPLOYING A COMBINATION OF FERRIC CHLORIDE AND AN IMIDAZOLIUM SALT IN BENZOTRIFLUORIDE Reviewed

    Chika Osawa, Minami Tateyama, Kensuke Miura, Eiji Tayama, Hajime Iwamoto, Eietsu Hasegawa

    HETEROCYCLES   86 ( 2 )   1211 - 1226   2012.12

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    Aza-Prins cyclization reactions of N-tosyl-3-butenylamine with p-methoxybenzaldehyde, 1-naphthaldehyde and 2-naphthaldehyde take place efficiently using a combination 1-butyl-3-methylimidazolium of ferric chloride and hexafluorophosphate in benzotrifluoride (Felm-BTF procedure). The new methodology, leading to formation of target N-tosyl-4-chloro-2-substituted piperidines, is superior to the one using 1-butyl-3-methylimidazolium tetrachloroferrate. The Felm-BTF procedure was also applied to aza-Prins cyclization reactions of other aldehydes. Finally, the effects of imidazolium salts on aza-Prins cyclization reaction promoted by boranetrifluoride-diethyl ether complex, leading to formation of fluorinated piperidines, were explored.

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  • Copper(II)-acid co-catalyzed intermolecular substitution of electron-rich aromatics with diazoesters Reviewed

    Eiji Tayama, Moe Ishikawa, Hajime Iwamoto, Eietsu Hasegawa

    TETRAHEDRON LETTERS   53 ( 38 )   5159 - 5161   2012.9

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    The intermolecular aromatic substitution of N,N-dialkylanilines and alkoxybenzenes with diazoesters is shown to proceed in the presence of catalytic amounts of both copper(II) salt and acid (Lewis or Bronsted). This method is a mild and rare metal-free C-C bond formation reaction between aromatic (sp(2)) and aliphatic (sp(3)) carbons. (C) 2012 Elsevier Ltd. All rights reserved.

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  • A formal method for the de-N,N-dialkylation of Sommelet-Hauser rearrangement products Reviewed

    Eiji Tayama, Ryota Sato, Keisuke Takedachi, Hajime Iwamoto, Eietsu Hasegawa

    TETRAHEDRON   68 ( 24 )   4710 - 4718   2012.6

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    Selective amine de-alkylation enables the conversion of Sommelet-Hauser rearrangement products into 2-aryl-2-bromoacetic acid derivatives. These compounds are valuable synthetic intermediates in the synthesis of alpha-aryl-alpha-amino or alpha-aryl-beta-amino acid derivatives. The method presented herein is a formal de-N,N-dialkylation of Sommelet-Hauser rearrangement products. (C) 2012 Elsevier Ltd. All rights reserved.

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  • 1,2-Dimethoxy-4,5-dimethylene: a new protecting group for acyclic amino acid derivatives prepared by Stevens rearrangement Reviewed

    Eiji Tayama, Keisuke Takedachi, Hajime Iwamoto, Eietsu Hasegawa

    TETRAHEDRON LETTERS   53 ( 11 )   1373 - 1375   2012.3

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    A new protecting group, 1,2-dimethoxy-4,5-dimethylene, for acyclic amino acid derivatives could be introduced by N,N-dialkylation with 1,2-bis(bromomethyl)-4,5-dimethoxybenzene (1) and removed via amine de-alkylation with acyl chlorides. The method can be used with base-induced [2,3] and [1,2] Stevens rearrangement products. (C) 2012 Elsevier Ltd. All rights reserved.

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  • Asymmetric alpha-2-tosylethenylation of N,N-dialkyl-L-amino acid esters via the formation of non-racemic ammonium enolates Reviewed

    Eiji Tayama, Tomohito Igarashi, Hajime Iwamoto, Eietsu Hasegawa

    ORGANIC & BIOMOLECULAR CHEMISTRY   10 ( 2 )   339 - 345   2012

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    Asymmetric alpha-2-tosylethenylation of (S)-2-(pyrrolidin-1-yl)propanoic acid esters was shown to produce good yields with high enantioselectivities. The reaction proceeds via the formation of a non-racemic ammonium enolate without an external source of chirality.

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  • Asymmetric alpha-2-tosylvinylation of in situ-generated N-2-tosylvinyl proline-derived ammonium ylides Reviewed

    Tomohito Igarashi, Eiji Tayama, Hajime Iwamoto, Eietsu Hasegawa

    TETRAHEDRON LETTERS   52 ( 15 )   1819 - 1821   2011.4

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    Asymmetric alpha-2-tosylvinylation of N-substituted proline esters using ethynyl tolyl sulfone as an electrophile was shown to proceed in good yield with high enantioselectivities without the addition of any bases. The reaction proceeds via the formation of N-2-tosylvinyl ammonium ylides. (C) 2011 Elsevier Ltd. All rights reserved.

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  • Copper(II) Triflate Catalyzed Intermolecular Aromatic Substitution of N,N-Disubstituted Anilines with Diazo Esters Reviewed

    Eiji Tayama, Tomoyo Yanaki, Hajime Iwamoto, Eietsu Hasegawa

    EUROPEAN JOURNAL OF ORGANIC CHEMISTRY   2010 ( 35 )   6719 - 6721   2010.12

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    The intermolecular aromatic substitution of N,N-disubstituted anilines with diazo esters is achieved under mild conditions in the presence of a catalytic amount of copper(II) triflate (up to 89% yield). The scope and limitations regarding substrates, diazo esters, and ligands in this reaction are described.

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  • Application of biphasic reaction procedure using ferric chloride dissolved in an imidazolium salt and benzotrifluoride (FeIm-BTF procedure) to aza-Prins cyclization reaction Reviewed

    Eietsu Hasegawa, Nohara Hiroi, Chika Osawa, Eiji Tayama, Hajime Iwamoto

    TETRAHEDRON LETTERS   51 ( 50 )   6535 - 6538   2010.12

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    Aza-Prins cyclization reaction of N-tosyl-3-butenylamine with aliphatic and aromatic aldehydes was performed using a combination of FeCl3 and 1-butyl-3-methylimidazolium hexafluorophosphate (BmimPF(6)) or 1-butyl-3-methylimidazolium tetrachloroferrate (BmimFeCl(4)) in benzotrifluoride (BTF). The desired N-tosyl-4-chloro-2-substituted piperidines were obtained from aliphatic aldehydes in comparable yields to those for the previously reported reactions in which FeCl3 was used in CH2Cl2. On the other hand, significant progress for the piperidine synthesis from aromatic aldehydes has been achieved, particularly when BmimFeCl(4) was used with FeCl3 in BTF. (C) 2010 Elsevier Ltd. All rights reserved.

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  • Remarkable enhancement effect of potassium tert-butoxide/THF solution in base-induced Sommelet-Hauser rearrangements Reviewed

    Eiji Tayama, Keisuke Takedachi, Hajime Iwamoto, Eietsu Hasegawa

    TETRAHEDRON   66 ( 48 )   9389 - 9395   2010.11

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    A solution of potassium tert-butoxide in THF was shown to remarkably enhance the base-induced Sommelet-Hauser rearrangement of N-benzylic amino acid-derived ammonium ylides. (C) 2010 Elsevier Ltd. All rights reserved.

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  • Resolution of nitrogen-centered chiral tetraalkylammonium salts: application to [1,2] Stevens rearrangements with N-to-C chirality transmission Reviewed

    Eiji Tayama, Seijun Otoyama, Hiroyuki Tanaka

    TETRAHEDRON-ASYMMETRY   20 ( 22 )   2600 - 2608   2009.11

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    The resolution of N-chiral, amino acid-derived quaternary ammonium salts is demonstrated by using chiral BINOL as a complexing agent. Determination of the enantiopurities and absolute configurations of the resolved N-chiral tetraalkylammonium salts are described. The [1,2] Stevens rearrangement of N-chiral ammonium salts is shown to proceed with N-to-C chirality transmission to afford optically active 3-substituted morpholin-2-one derivatives. (C) 2009 Elsevier Ltd. All rights reserved.

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  • New synthetic routes to optically active alpha-quaternary alpha-aryl amino acid derivatives via the diastereoselective Stevens and Sommelet-Hauser rearrangements Reviewed

    Eiji Tayama, Kiwako Orihara, Hiroshi Kimura

    ORGANIC & BIOMOLECULAR CHEMISTRY   6 ( 20 )   3673 - 3680   2008.10

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    The Stevens rearrangement of N-allylic alpha-aryl amino acid-derived ammonium salts and the Sommelet-Hauser rearrangement of N-benzylic alpha-alkyl amino acid-derived ammonium salts are shown to proceed with remarkably high levels of diastereoselectivity. The methods presented in this work provide new routes to optically active alpha-quaternary alpha-aryl amino acid derivatives.

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  • Bronsted acid catalyzed regioselective aza-Ferrier reaction: a novel synthetic method for alpha-(N-Boc-2-pyrrolidinyl) aldehydes Reviewed

    Eiji Tayama, Seijun Otoyama, Wataru Isaka

    CHEMICAL COMMUNICATIONS   ( 35 )   4216 - 4218   2008

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    The 1,4-elimination reaction of (Z)-N-Boc-2-(4-methoxy-2-alkenyloxy)pyrrolidines (1) is shown to proceed with high (1E, 3E)-stereoselectivity to afford N-Boc-2-(1,3-dienyloxy)pyrrolidines (2); the Bronsted acid catalyzed aza-Ferrier reaction of the N-Boc-2-(1,3-dienyloxy) pyrrolidines (2) provides alpha-(N-Boc-2- pyrrolidinyl) aldehydes (3) in excellent yields with high alpha-regioselectivities.

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  • A facile synthetic method of alpha-quaternary-beta,gamma-unsaturated aldehydes via the stereoselective 1,4-elimination and alpha-regioselective Ferrier reaction Reviewed

    Eiji Tayama, Ryo Hashimoto

    TETRAHEDRON LETTERS   48 ( 45 )   7950 - 7952   2007.11

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    The 1,4-elimination reaction of 2-substituted-(2Z)-4-methoxy-O-alkenyl acetals with n-butyllithium is shown to afford the 2-substituted-(1Z,3E)-O-1,3-dienyl acetals in high stereoselectivities. The Ferrier reaction of the O-1,3-dienyl acetals thus obtained provides the corresponding alpha-quaternary-beta,gamma-unsaturated aldehydes in excellent yields with high alpha-regioselectivities. (c) 2007 Elsevier Ltd. All rights reserved.

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  • A facile method for the stereoselective preparation of (1E,3E)-4-substituted-1-amino-1,3-dienes via 1,4-elimination Reviewed

    Eiji Tayama, Sayaka Sugai

    TETRAHEDRON LETTERS   48 ( 35 )   6163 - 6166   2007.8

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    The 1,4-elimination reaction of 1-amino-4-methoxy-(2Z) -alkenes is shown to proceed with high (1E,3E)-stereoselectivities to afford the corresponding 4-substituted-1-amino-1,3-dienes in good yield. The scope and stereochemical features of the synthetic method are described. (c) 2007 Elsevier Ltd. All rights reserved.

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  • An efficient optical resolution of nitrogen-centered chiral beta-hydroxy-tetraalkylammonium salts via complexation with (R)-BINOL Reviewed

    Eiji Tayama, Hiroyuki Tanaka

    TETRAHEDRON LETTERS   48 ( 24 )   4183 - 4185   2007.6

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    The optical resolution of nitrogen-centered chiral beta-hydroxy-tetraalkylammonium bromides is demonstrated by using chiral BINOL as a complexing agent. Determination of the enantiopurities and absolute configurations of the resolved N-chiral tetraalkylammonium salts are described. (c) 2007 Elsevier Ltd. All rights reserved.

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  • Asymmetric Sommelet-Hauser rearrangement of N-benzylic ammonium salts Reviewed

    Eiji Tayama, Hiroshi Kimura

    ANGEWANDTE CHEMIE-INTERNATIONAL EDITION   46 ( 46 )   8869 - 8871   2007

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    DOI: 10.1002/anie.200703832

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  • Regio- and stereoselective ferrier reaction of O-1,3-dienyl acetals promoted by organoaluminum complexes Reviewed

    Eiji Tayama, Wataru Isaka

    ORGANIC LETTERS   8 ( 24 )   5437 - 5439   2006.11

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    The Ferrier reaction of O-1,3-dienyl acetals promoted by organoaluminum complexes such as methylaluminum bis(2,6-di-tert-butyl-4-methylphenoxide) (MAD) is shown to proceed with a high degree of regio- and stereoselectivity to afford the corresponding alpha-alkenyl-substituted beta-alkoxy aldehydes in good yields. The mechanistic origin of the high regiocontrolling ability of MAD is elucidated. This method, coupled with the easy availability of the requisite substrates, expands the synthetic scope of the Ferrier reaction.

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  • A facile and stereoselective synthetic method for allylic 1,3-dienyl ethers Reviewed

    Eiji Tayama, Sayaka Sugai, Masahiro Hara

    TETRAHEDRON LETTERS   47 ( 43 )   7533 - 7535   2006.10

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    The 1,4-elimination reaction of 1-allyloxy-4-methoxy-(2Z)-alkenes with n-butyllithium is shown to proceed in a marked preference to the [2,3] Wittig rearrangement to afford the allylic (1Z,M)-dienyl ethers in high stereoselectivities. The synthetic utility of this method is demonstrated by the Claisen rearrangement of the dienyl ethers thus obtained. (c) 2006 Elsevier Ltd. All rights reserved.

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  • Asymmetric [1,2] Stevens rearrangement of (S)-N-benzylic proline-derived ammonium salts under biphasic conditions Reviewed

    Eiji Tayama, Shintaro Nanbara, Takeshi Nakai

    CHEMISTRY LETTERS   35 ( 5 )   478 - 479   2006.5

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    The Stevens rearrangement of (S)-N-benzylic proline-derived ammonium salt with cesium hydroxide in 1,2-dichloroethane is shown to proceed with a high degree of the N-to-C chirality transmission to afford the alpha-substituted proline derivatives in high enantio-purities.

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  • A facile method for the stereoselective preparation of (1Z,3E)-dienyl ethers via 1,4-elimination of 1,4-dialkoxy-(2Z)-alkenes with n-butyllithium Reviewed

    E Tayama, S Sugai

    SYNLETT   2006 ( 6 )   849 - 852   2006.4

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    Treatment of l-alkoxy-4-methoxy-(2Z)-alkenes or l-siloxy-4-methoxy-(2Z)-alkenes with n-butyllithium in diethyl ether is shown to afford the corresponding (1Z,3E)-dienyl, alkyl or silyl ethers, respectively, in high stereoselectivity via a facile 1,4-elimination. The scope and the regio- and stereochemical features of the synthetic method are described.

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  • Kinetic resolution via the [2,3] Stevens rearrangement of epimeric six-membered ammonium ylides: A new entry to enantio-enriched alpha-amino acid derivatives Reviewed

    E Tayama, H Tanaka, T Nakai

    HETEROCYCLES   66 ( 1 )   95 - 99   2005.12

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    The asymmetric [2,3] Stevens rearrangement of epimeric mixtures of N-allylic ammonium salts derived from (5R)-5-phenyl-1,4-oxazin-2-one is shown to proceed with efficient kinetic resolution to afford the unnatural alpha-amino acid derivatives in high enantio-purities.

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  • Highly enantioselective phase-transfer-catalyzed alkylation of protected alpha-amino acid amides toward practical asymmetric synthesis of vicinal diamines, alpha-amino ketones, and alpha-amino alcohols Reviewed

    T Ooi, M Takeuchi, D Kato, Y Uematsu, E Tayama, D Sakai, K Maruoka

    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY   127 ( 14 )   5073 - 5083   2005.4

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    Highly enantioselective alkylation of protected glycine diphenylmethyl (Dpm) amide 1 and Weinreb amide 10 has been realized under phase-transfer conditions by the successful utilization of designer chiral quaternary ammonium salts of type 4 as catalyst. Particularly, remarkable reactivity of the chiral ammonium enolate derived from 1b and 4c allowed the reaction with less reactive simple secondary alkyl halides with high efficiency and enantioselectivity. An additional unique feature of this chiral ammonium enolate is its ability to recognize the chirality of beta-branched primary alkyl halides, which provides impressive levels of kinetic resolution and double stereodifferentiation during the alkylation, allowing for two alpha- and gamma-stereocenters to be controlled. Combined with the subsequent reduction using LiAlH4 in cyclopentyl methyl ether (CPME), this system offers a facile access to structurally diverse optically active vicinal diamines. Furthermore, the optically active a-amino acid Weinreb amide 11 can be efficiently converted to the corresponding amino ketone by a simple treatment with Grignard reagents. In addition, reduction and alkylation of the optically active alpha-amino ketone into both syn and anti alpha-amino alcohols with almost complete relative and absolute stereochemical control have been achieved. With (S,S)- and (R,R)-4 in hand, the present approach renders both enantionners of alpha-amino amides including Weinreb amides readily available with enormous structural variation and also establishes a general and practical route to vicinal diamines, a-amino ketones, and a-amino alcohols with the desired stereochemistry.

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  • Palladium-catalyzed intramolecular coupling between aryl iodides and allyl moieties via thermal and microwave-assisted conditions Reviewed

    M Lautens, E Tayarna, C Herse

    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY   127 ( 1 )   72 - 73   2005.1

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  • Activation and stabilization of aldimines by an ortho-trifluoromethyl substituent in direct vinylogous Mannich-type reactions Reviewed

    M Lautens, E Tayama, D Nguyen

    TETRAHEDRON LETTERS   45 ( 26 )   5131 - 5133   2004.6

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    Lewis acid catalyzed direct vinylogous Mannich-type reaction with a weak nucleophile dienol, generated in situ by ringopening and rearrangement of vinyloxiranes, could be demonstrated in excellent yields under mild conditions using benzylidene(4-methoxy-2-trifluoromethvl)aniline (MTMA) as an electrophile. The o-trifluoromethyl substituent can stabilize imines by a steric effect and activate by an electron-withdrawing effect. It proved to be an easily deprotectable protecting group for direct Mannich-type reactions. (C) 2004 Elsevier Ltd. All rights reserved.

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  • Stereoselective terminal functionalization of small peptides for catalytic asymmetric synthesis of unnatural peptides Reviewed

    K Maruoka, E Tayama, T Ooi

    PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA   101 ( 16 )   5824 - 5829   2004.4

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    The asymmetric phase-transfer catalytic alkylation of peptides has been achieved by the use of designed C-2-symmetric chiral quaternary ammonium bromide 1 as catalyst. Excellent stereoselectivities were uniformly observed in the alkylation with a variety of alkyl halides and the efficiency of the transmission of stereochemical information was not affected by the side-chain structure of the preexisting amino acid residues. This method also enables an asymmetric construction of noncoded alpha,alpha-dialkyl-alpha-amino acid residues at the peptide terminal. Since this chirality can be efficiently transferred to the adjacent amino acid moiety, our approach provides a general procedure not only for the highly stereoselective terminal functionalization of peptides but also for the sequential asymmetric construction of unnatural oligopeptides, which should play a vital role in the peptide-based drug discovery process.

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  • (2,7-disubstituted-1,8-biphenylenedioxy)bis(dimethylaluminum) as bidentate organoaluminum Lewis acids: Elucidation and synthetic utility of the double electrophilic activation phenomenon Reviewed

    T Ooi, M Takahashi, M Yamada, E Tayama, K Omoto, K Maruoka

    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY   126 ( 4 )   1150 - 1160   2004.2

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    A series of (2,7-disubstituted-1,8-biphenylenedioxy)bis(dimethylaluminum) (2) has been readily prepared in situ by treatment of the requisite 2,7-disubstituted-1,8-biphenylenediol (1) with Me3Al (2 equiv) in CH2Cl2 at room temperature; this primarily relies on the successful establishment of a new synthetic procedure of 1 starting from inexpensive m-anisidine. Evaluation of 2 as a bidentate organoaluminum Lewis acid has been performed by the reduction of ketonic substrates using Bu3SnH as a hydride source in comparison to the conventional monodentate Lewis acid dimethylaluminum 2,6-xylenoxide (11), uncovering the significantly high activation ability of 2 toward carbonyl. Particularly, (2,7-dimethyl-1,8-biphenylenedioxy)bis(dimethylaluminum) (2a) exerted the highest reactivity, which has also been emphasized in the Mukaiyama aldol reaction. The structure of the bidentate Lewis acid 2 was unambiguously determined by single-crystal X-ray diffraction analysis of 2g possessing a bulky 3,5-di-tert-butylphenyl substituent, revealing the rigid dimeric assembly in the solid state. The double electrophilic activation of carbonyl substrate by 2a has been supported by low-temperature C-13 NMR analysis as well as theoretical study using the Gaussian 98 program. Moreover, unique stereoselectivity has been observed in the 2a-promoted Mukaiyama Michael addition, and highly chemoselective functionalization of carbonyl compounds in the presence of their acetal counterparts has been realized using 2a. Finally, the effectiveness of 2a for the activation of ether functionality has been demonstrated in the Claisen rearrangement of allyl vinyl ethers.

    DOI: 10.1021/ja030552s

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    Other Link: http://orcid.org/0000-0002-0309-9507

  • Direct vinylogous Mannich-type reactions via ring opening and rearrangement of vinyloxiranes Reviewed

    M Lautens, E Tayama, D Nguyen

    ORGANIC LETTERS   6 ( 3 )   345 - 347   2004.2

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    The first synthetic application of 2-methyl-2-vinyloxirane as a masked dienolate has been successfully demonstrated in the direct vinylogous Mannich-type reaction with an alpha-imino ester as an electrophile. The Mannich adduct was a useful intermediate en route to cis-5-substituted pipecolinic acid ethyl ester under simple hydrogenation conditions.

    DOI: 10.1021/ol036153j

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  • Practical asymmetric synthesis of vicinal diamines through the catalytic highly enantioselective alkylation of glycine amide derivatives Reviewed

    T Ooi, D Sakai, M Takeuchi, E Tayama, K Maruoka

    ANGEWANDTE CHEMIE-INTERNATIONAL EDITION   42 ( 47 )   5868 - 5870   2003

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:WILEY-V C H VERLAG GMBH  

    DOI: 10.1002/anie.200352658

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    Other Link: http://orcid.org/0000-0002-0309-9507

  • Highly stereoselective N-terminal functionalization of small peptides by chiral phase-transfer catalysis Reviewed

    T Ooi, E Tayama, K Maruoka

    ANGEWANDTE CHEMIE-INTERNATIONAL EDITION   42 ( 5 )   579 - +   2003

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:WILEY-V C H VERLAG GMBH  

    DOI: 10.1002/anie.200390167

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  • Activation of ether functionality of allyl vinyl ethers by chiral bis(organoaluminum) Lewis acids: application to asymmetric Claisen rearrangement Reviewed

    E Tayama, A Saito, T Ooi, K Maruoka

    TETRAHEDRON   58 ( 41 )   8307 - 8312   2002.10

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:PERGAMON-ELSEVIER SCIENCE LTD  

    Chiral bis(organoaluminum) Lewis acids have been newly designed and synthetic utility of their eminent activation ability of an ether functionality has been successfully demonstrated by the application to asymmetric Claisen rearrangement of allyl vinyl ethers. (C) 2002 Elsevier Science Ltd. All rights reserved.

    DOI: 10.1016/S0040-4020(02)00981-X

    DOI: 10.1016/s0040-4020(02)00981-x

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  • Remarkable template effect of a Lewis acid receptor in the intramolecular radical cyclization: control of reaction pathway as well as stereochemistry Reviewed

    T Ooi, Y Hokke, E Tayama, K Maruoka

    TETRAHEDRON   57 ( 1 )   135 - 144   2001.1

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    A remarkable template effect in the intramolecular radical cyclization process has been observed by the successful utilization of Lewis acid receptor, aluminum tris(2,6-diphenylphenoxide) (ATPH). The origin of this efficient template effect by ATPH would be ascribable to the well-defined reaction environment created in front of the aluminum coordination center; this enables appropriate proximity of initially generated carbon radical to unsaturated carbon-carbon bond in the transition state for smooth cyclization and hence completely suppresses the undesired intermolecular reduction pathway. Moreover, such conformational restriction provided by the unique cavity of ATPH alters the stereoselectivity of the cyclization. (C) 2000 Elsevier Science Ltd. All rights reserved.

    DOI: 10.1016/S0040-4020(00)01007-3

    DOI: 10.1016/s0040-4020(00)01007-3

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  • Dramatic rate enhancement by ultrasonic irradiation in liquid-liquid phase-transfer catalytic reactions Reviewed

    T Ooi, E Tayama, K Doda, M Takeuchi, K Maruoka

    SYNLETT   ( 10 )   1500 - 1502   2000.10

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:GEORG THIEME VERLAG  

    Significant rate enhancement was observed in the liquid-liquid phase-transfer catalytic epoxidations and alkylations under ultrasonic irradiation. Its advantage was also demonstrated in the asymmetric alkylation of tert-butyl glycinate-benzophenone Schiff base using C-2-symmetric chiral phase-transfer catalyst.

    DOI: 10.1055/s-2000-7652

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  • Dramatic enhancement of reactivity of organosilicon compounds induced by complexation of bis(allyl)silanes with fluoride ion Reviewed

    A Shibato, Y Itagaki, E Tayama, Y Hokke, N Asao, K Maruoka

    TETRAHEDRON   56 ( 30 )   5373 - 5382   2000.7

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    New type of fluoride ion catalyzed allylation agent (1a, 1b), allenylation agent (9, 10), and alkynylation agent (17) can be successfully utilized for various carbonyl substrates. The rate acceleration is ascribable to the shift of equilibrium to the chelate complexes with Bu4NF by the favorable chelation of bis(silyl) compounds toward the fluoride ion. The F-19 NMR spectrum (ethyl trifluoroacetate as external standard) of a mixture of 1a and Bu4NF in CDCl3 showed two peaks at delta -81.75 and -77.67 (integration ratio similar to 9:1). The large signal corresponds to the original peak of Bu4NF and the small one might be ascribed to the chelate complex [B] between la and Bu4NF. The fluoride ion mediated reaction of bis(crotyldimethylsilyl)methane (7) with benzaldehyde was examined and the only gamma-adduct 8 was obtained regioselectively. (C) 2000 Elsevier Science Ltd. All rights reserved.

    DOI: 10.1016/S0040-4020(00)00458-0

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  • Efficient synthesis of aromatic sec-amides from esters: Synthetic utility of bislithium amides Reviewed

    T Ooi, E Tayama, M Yamada, K Maruoka

    SYNLETT   1999 ( 6 )   729 - 730   1999.6

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    Convenient, efficient preparation of aromatic sec-amides from esters has been accomplished using dilithium amides which are easily prepared by treatment of aromatic amines with 2 equiv of BuLi in THF. This new method allows a facile formation of amide bond even with sterically hindered esters.

    DOI: 10.1055/s-1999-2731

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  • Bidentate organoaluminum Lewis acid for selective activation of carbonyl over acetal functionality: Chemoselective functionalization Reviewed

    T Ooi, E Tayama, M Takahashi, K Maruoka

    TETRAHEDRON LETTERS   38 ( 42 )   7403 - 7406   1997.10

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    Chemoselective functionalization of carbonyl compounds over acetals has been achieved by bidentate organoaluminum Lewis acid based on the selective double electrophilic activation of carbonyls. (C) 1997 Elsevier Science Ltd.

    DOI: 10.1016/S0040-4039(97)01735-8

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Awards

  • Award in Synthetic Organic Chemistry, Japan

    2004   The Society of Synthetic Organic Chemistry  

    TAYAMA Eiji

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Research Projects

  • 非配位性アニオン・キラル四炭素置換ボレートによるカチオン種の不斉認識

    Grant number:20K05508

    2020.4 - 2024.3

    System name:科学研究費助成事業

    Research category:基盤研究(C)

    Awarding organization:日本学術振興会

    田山 英治

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    Grant amount:\4420000 ( Direct Cost: \3400000 、 Indirect Cost:\1020000 )

    研究代表者は、第四級アンモニウム塩の光学純度を決定する手法を2019年に発表し、この成果を基盤として2020年度から本研究課題を開始している。キラルビナフチル骨格を有する四炭素置換ボレート陰イオンを合成し、第四級アンモニウム塩に作用させることでジアステレオマー混合物塩を形成させる。そのプロトンNMR分析により第四級アンモニウム塩の光学純度が決定できる。2020年度に得られた結果に基づいた2021年度の実績を以下に示す。
    (1)2020年度の研究成果の論文発表:2020年度の研究成果「キラルテトラアルキニルボレートによるN-キラル第四級アンモニウム塩の不斉認識」は、論文投稿に必要な実験データは95%揃っていたが、この段階で主要分析機器である700MHz NMR(学内共同利用機器)が故障したため全て揃わず、論文投稿と発表が遅れていた。当該機器は2021年度に修理されて使用可能となり、残ったデータ収集により論文発表に至った。
    (2)キラルボレートの新しいリンカー部の発見:(1)で述べたように、2021年度の大半は主要分析機器である700MHz NMR(学内共同利用機器)が使用不可となり、キラルボレートの不斉認識能を評価する環境が不充分であった。汎用の400MHz NMRでも研究を進めることは不可能ではなかったが、非効率と判断した。そこで2021年度はキラルボレートの構造デザイン、特にホウ素原子と結合させるリンカー基の構造について主に検討を行った。これまでのリンカー基の例はPommereningらによるテトラフルオロフェニル基、研究代表者によるプロパルギルエーテル基の二種類のみであり、それぞれ長所と短所があった。リンカー基について各種検討したところ、テトラフルオロフェニルエーテル基が、リンカー基の導入の容易さと、ボレート形成に必要な反応性、の両者を兼ね備えていることを見出した。

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  • Design of chiral calix arene for synthesis of optically-active unnatural amino acids by asymmetric complexation

    Grant number:23750037

    2011 - 2013

    System name:Grants-in-Aid for Scientific Research

    Research category:Grant-in-Aid for Young Scientists (B)

    Awarding organization:Japan Society for the Promotion of Science

    TAYAMA Eiji

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    Grant amount:\4550000 ( Direct Cost: \3500000 、 Indirect Cost:\1050000 )

    Optically-active large cyclic compounds were prepared from calix arenes. NMR analysis of a 1:1 complex between the chiral calix arene and a racemic tetraalkylamkmonium salt was examined. Each enantiomer of the tetraalkylammonium salt were observed separately in the spectrum. Asymmetric rearrangements of the tetraalkylammonium salts using the chiral calix arenes as an organo-catalyst were examined. The rearrangement products were successfully converted to the corresponding unnatural amino acids.

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  • The Study of Nitrogen Chirality: Development of Preparative Method and Application to Organic Synthesis

    Grant number:19750029

    2007 - 2008

    System name:Grants-in-Aid for Scientific Research

    Research category:Grant-in-Aid for Young Scientists (B)

    Awarding organization:Japan Society for the Promotion of Science

    TAYAMA Eiji

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    Grant amount:\3650000 ( Direct Cost: \3500000 、 Indirect Cost:\150000 )

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  • 立体選択的脱離反応を機軸とした、効率的炭素-炭素結合形成反応の実現

    Grant number:18037021

    2006

    System name:科学研究費助成事業

    Research category:特定領域研究

    Awarding organization:日本学術振興会

    田山 英治

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    Grant amount:\1700000 ( Direct Cost: \1700000 )

    有機合成化学の社会的重要性の高まりに伴い、炭素-炭素結合を効率的に構築する手法の開発が強く求められている。この目的を満たす反応は、複雑な分子骨格を瞬時に構築でき、かっ「完壁な原子効率」で進行するDiels-Alder反応、シグマトロピー反応、転位反応であることは明らかであり、これらの反応に適用可能な反応活性種を効率よく合成することは炭素-炭素結合形成反応の効率化に結びつく。そこで、更なる合成反応に適用可能である1位に酸素原子を有する活性ジエン類を、1,4-脱離反応を利用して効率的に合成することを試みた。
    容易に合成可能な1,4-ブテンジオール誘導体をエーテル中、ブチルリチウムで処理すると、キレート中間体を経た1,4-脱離反応が進行し、ほぼ単一の立体化学(1Z,3E)を有する1,3-ジエニルエーテルが得られることを見出した。
    本法は基質の1位の酸素原子上、及び4位の炭素原子上に様々な置換基を導入することが可能であり、多彩な活性ジエン類を合成できるという特徴を有している。特に1位の酸素原子上に導入する置換基の種類により、向山アルドール反応に適用可能なジエニルシリルエーテルに限らず、Ferrier反応に適用可能なジエニルアセタールやクライゼン転位反応に適用可能なアリルジエニルエーテルが簡便、かつ高立体選択的に合成でき、更なる合成反応への展開が可能であるという点で本法は優れていることを示した。

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  • 新規不斉触媒骨格の構築を志向したキラル四級窒素合成法の開発

    Grant number:17750034

    2005 - 2006

    System name:科学研究費助成事業

    Research category:若手研究(B)

    Awarding organization:日本学術振興会

    田山 英治

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    Grant amount:\3700000 ( Direct Cost: \3700000 )

    1,窒素上に不斉中心を有する四級アンモニウム塩の光学分割:一般性の検討
    窒素上の四つの置換基がそれぞれ異なる四級アンモニウム塩、N-allyl-N-benzyl-N-(2-hydroxyethyl)-N-methylammonium bromideを合成し、この基質にエタノール中、0.5等量の光学活性ビナフトールを作用させると光学分割が起こり、高いエナンチオ選択性で窒素原子上に不斉を有する四級アンモニウム塩が得られる、という前年度の研究成果について一般性の検討を行った。その結果、導入する置換基により本法の成否が決まることが分かり、如何なる置換基を導入すれば光学分割に望ましいかの知見を得た。また、四級アンモニウム塩のカウンターアニオンとして数種検討したところ、bromide塩よりもchloride塩の方が効率よく光学分割が起こる傾向が見られた。
    2,N-キラル四級アンモニウム塩の絶対配置の決定
    光学分割した窒素上に不斉中心を有する四級アンモニウム塩の絶対配置は、X線結晶構造解析を行うことで決定に成功した。具体的には、四級アンモニウム塩であるN-allyl-N-benzyl-N-(2-hydroxyethyl)-N-methylammonium bromideに光学活性ビナフトールを作用させることで得られる1:1複合体は、エタノール中で再結晶を行うことでX線結晶構造解析に望ましい単結晶として得られることがわかった。これをX線結晶構造解析したところ、(R)体の光学活性ビナフトールを光学分割剤として用いた場合には、窒素原子上の絶対配置が(S)である四級アンモニウム塩(S)-N-allyl-N-benzyl-N-(2-hydroxyethyl)-N-methylammonium bromideが得られることがわかった。

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Teaching Experience

  • 先端科学技術総論

    2023
    Institution name:新潟大学

  • 理学基礎演習

    2022
    Institution name:新潟大学

  • 統合化学入門

    2022
    Institution name:新潟大学

  • 有機合成方法論I

    2022
    Institution name:新潟大学

  • コミュニケーション演習

    2022
    Institution name:新潟大学

  • 科学技術英語

    2022
    Institution name:新潟大学

  • 化学コロキウム

    2021
    Institution name:新潟大学

  • 課題研究

    2021
    Institution name:新潟大学

  • 化学特論II

    2021
    Institution name:新潟大学

  • 課題研究 a

    2020
    Institution name:新潟大学

  • 課題研究 b

    2020
    Institution name:新潟大学

  • 有機化学Ⅲ

    2017
    Institution name:新潟大学

  • 化学基礎実習a

    2017
    Institution name:新潟大学

  • 自然科学基礎実験

    2017
    Institution name:新潟大学

  • 化学基礎実習b

    2017
    Institution name:新潟大学

  • 専門力アクティブ・ラーニング

    2017
    -
    2021
    Institution name:新潟大学

  • 理学スタディ・スキルズ

    2017
    -
    2020
    Institution name:新潟大学

  • 課題研究

    2017
    -
    2019
    Institution name:新潟大学

  • 自然科学総論Ⅰ

    2014
    Institution name:新潟大学

  • Basic Chemistry Ⅱ

    2013
    Institution name:新潟大学

  • 科学技術英語

    2012
    -
    2022
    Institution name:新潟大学

  • コミュニケーション演習

    2012
    -
    2022
    Institution name:新潟大学

  • 大型機器分析技術

    2012
    Institution name:新潟大学

  • 有機化学III

    2010
    Institution name:新潟大学

  • グリーンケミストリー概説

    2010
    -
    2013
    Institution name:新潟大学

  • 不斉有機合成論

    2009
    Institution name:新潟大学

  • 有機化学演習

    2009
    Institution name:新潟大学

  • 有機化学実験

    2009
    Institution name:新潟大学

  • 数理物質科学演習Ⅰ(化学)

    2009
    -
    2020
    Institution name:新潟大学

  • 有機合成方法論Ⅰ

    2009
    -
    2020
    Institution name:新潟大学

  • スタディ・スキルズ(化学学習法)

    2009
    -
    2020
    Institution name:新潟大学

  • 数理物質科学特定研究ⅡA(化学)

    2009
    -
    2020
    Institution name:新潟大学

  • 課題研究(化学科)

    2009
    -
    2020
    Institution name:新潟大学

  • 数理物質科学特定研究ⅡB(化学)

    2009
    -
    2020
    Institution name:新潟大学

  • 数理物質科学特定研究Ⅰ(化学)

    2009
    -
    2020
    Institution name:新潟大学

  • 反応有機化学

    2008
    -
    2013
    Institution name:新潟大学

  • 化学実験I

    2007
    -
    2008
    Institution name:新潟大学

  • 安全教育

    2007
    -
    2008
    Institution name:新潟大学

  • 化学実験

    2004
    -
    2020
    Institution name:新潟大学

  • 化学コロキュウム

    2003
    -
    2020
    Institution name:新潟大学

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