Faculty Profiles - OOI Takashi

Papers - OOI Takashi

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Photocatalytic carbyne reactivity of phosphorus ylides for three-component formal cycloaddition reactions Reviewed International coauthorship

Ryuhei Suzuki, Taiga Ando, Fritz Deufel, Kohsuke Ohmatsu, and Takashi Ooi

Nature Synthesis Vol. 3 page： 1385 - 1391 2024.7

p-Diarylboryl Halothiophenols as Multifunctional Catalysts via Photoactive Intramolecular Frustrated Lewis Pairs Reviewed Open Access

Takeru Kikura, Yuya Taura, Yoshitaka Aramaki, and Takashi Ooi

Journal of the American Chemical Society Vol. 146 ( 29 ) page： 20425 - 20431 2024.7

Zwitterionic Acridinium Amidate: A Nitrogen-Centered Radical Catalyst for Photoinduced Direct Hydrogen Atom Transfer Reviewed International coauthorship Open Access

Lukas Entgelmeier, Soichiro Mori, Shion Sendo, Rie Yamaguchi, Ryuhei Suzuki, Takeshi Yanai, Olga García Mancheño, Kohsuke Ohmatsu, and Takashi Ooi

Angewandte Chemie International Edition Vol. 63 ( 43 ) page： e202404890 2024.6

If the Crown Fits: Sterically Demanding N-Heterocyclic Carbene Promotes the Formation of Au8Pt Nanocluster Reviewed International coauthorship

Joseph F. DeJesus, Samuel I. Jacob, Quan Manh Phung, Koichi Mimura, Yoshitaka Aramaki, Takashi Ooi, Masakazu Nambo, Cathleen M. Crudden

Journal of the American Chemical Society Vol. 146 ( 34 ) page： 23806 - 23813 2024.8

Catalytic 1,1-Cyanoalkylation of Electron-Deficient Olefins Reviewed

Kohsuke Ohmatsu, Duc An Truong, Shohei Morita, Keiji Maruoka, and Takashi Ooi

Organic Letters Vol. 26 ( 19 ) page： 4055 - 4058 2024.5

個性を創るもの，継ぐもの

大井貴史

有機合成化学協会誌 Vol. 81 ( 10 ) page： 929 - 929 2023.10

Excited-state tris(pentafluorophenyl)borane as a strong single-electron oxidant: Photophysical properties and catalysis Invited Reviewed

Yoshitaka Aramaki, Yuki Uchida, Ryo Ishikawa, and Takashi Ooi

Journal of Photochemistry and Photobiology 2023.8

Catalytic Formal Carbyne Transformation of Phosphorus Ylides Reviewed

Ryuhei Suzuki, Taiga Ando, Fritz Deufel, Kohsuke Ohmatsu, and Takashi Ooi

ChemRxiv 2023.8

Zwitterionic Diphenylphosphinyl Amidate as a Powerful Photoinduced Hydrogen-Atom-Transfer Catalyst for C-H Alkylation of Simple Alkanes. Reviewed

Ohmatsu K, Suzuki R, Fujita H, Ooi T

The Journal of organic chemistry Vol. 88 ( 10 ) page： 6553 - 6556 2023.5

Hydrogen-Atom Transfer Catalysis for C–H Alkylation of Benzylic Fluorides Reviewed

Kohsuke Ohmatsu, Hiroki Fujita, Ryuhei Suzuki, Takashi Ooi

2022.4

In Silico Analysis and Synthesis of Nafamostat Derivatives and Evaluation of Their Anti-SARS-CoV-2 Activity Reviewed

Fujimoto KJ, Hobbs DCF, Umeda M, Nagata A, Yamaguchi R, Sato Y, Sato A, Ohmatsu K, Ooi T, Yanai T, Kimura H, Murata T

Viruses Vol. 14 ( 2 ) page： 389 2022.2

Thioamidate Ion as Effective Cocatalyst for Photoinduced C–H Alkylation via Multisite Proton-coupled Electron Transfer Reviewed

Kohsuke Ohmatsu ,Haruka Fujimori ,Kodai Minami ,Kosuke Nomura ,Mari Kiyokawa , and Takashi Ooi

2022.2

Hydrogen-Atom-Transfer-Mediated Acceptorless Dehydrogenative Cross-Coupling Enabled by Multiple Catalytic Functions of Zwitterionic Triazolium Amidate Reviewed

Kodai Minami, Kohsuke Ohmatsu, and Takashi Ooi

ACS Catalysis Vol. 12 ( 3 ) page： 1971 - 1976 2022.1

Catalytic Asymmetric Strecker Reaction of Ketoimines with Potassium Cyanide Reviewed

Kohsuke Ohmatsu, Yusuke Morita, Mari Kiyokawa, Kimihiro Hoshino, and Takashi Ooi

Asian Journal of Organic Chemistry Vol. 10 ( 12 ) page： 3237 - 3240 2021.10

o-Quinone methide with overcrowded olefinic core as a catalytically-active surrogate of triarylmethylium salt for dehydridative oxidationof benzylic alcohols under aerobic photoirradiation conditions Reviewed

Kohsuke Kato, Daisuke Uraguchi, and Takashi Ooi

Tetrahedron Vol. 100 ( 5 ) page： 132459 2021.9

o-Quinone methide with overcrowded olefinic core as a catalytically-active surrogate of triarylmethylium salt for dehydridative oxidation of benzylic alcohols under aerobic photoirradiation conditions Reviewed

Kohsuke Kato, Daisuke Uraguchi, Takashi Ooi

Tetrahedron 2021.9

Synthesis and enantioseparation of chiral Au13 nanoclusters protected by bis-N-heterocyclic carbene ligands Reviewed

Yi H, Osten KM, Levchenko TI, Veinot AJ, Aramaki Y, Ooi T, Nambo M, Crudden CM

Chemical science Vol. 12 ( 31 ) page： 10436 - 10440 2021.8

Catalytic Asymmetric Cyanoalkylation of Electron-Deficient Olefins with Potassium Cyanide and Alkyl Halides Reviewed

Kohsuke Ohmatsu, Yusuke Morita, Mari Kiyokawa, Takashi Ooi

Journal of the American Chemical Society Vol. 143 ( 29 ) page： 11218 - 11224 2021.7

Synthesis and enantioseparation of chiral Au13 nanoclusters protected by bis-N-heterocyclic carbene ligands Reviewed

Hong Yi, Kimberly M. Osten, Tetyana I. Levchenko, Alex J. Veinot, Yoshitaka Aramaki, Takashi Ooi, Masakazu Nambo and Cathleen M. Crudden

Chemical Science 2021.7

Exploiting Transient Radical Cations as Brønsted Acids for Allylic C-H Heteroarylation of Enol Silyl Ethers Reviewed

Tsubasa Nakashima, Haruka Fujimori, Kohsuke Ohmatsu , Takashi Ooi

Chemistry-A European Journal Vol. 27 ( 36 ) page： 9253 - 9256 2021.6

Catalysis of Chiral Iminophosphorane for Simultaneous Control of Multiple Selectivity: Experimental and Theoretical Investigation Reviewed

Daisuke Uraguchi, Takashi Ooi

Journal of Synthetic Organic Chemistry, Japan Vol. 79 ( 5 ) page： 406 - 416 2021.5

Authorship：Corresponding author Language：Japanese Publishing type：Research paper (scientific journal) Publisher：The Society of Synthetic Organic Chemistry, Japan

Simultaneous control of multiple selectivity is a powerful means for constructing structurally discrete, functionalized building blocks, yet it has remained a challenging task in organic synthesis and catalysis. We have tackled this objective by taking advantage of the unique ability of P-spiro chiral tetraaminophosphonium ion to control transition-state structures of the target reaction. Namely, the use of its conjugate base, chiral iminophosphorane, as an organic base catalyst allowed for the rigorous control of not only enantioselectivity but also additional selectivity associated with other factors, such as geometry, regiochemistry, diastereomer formation, and reaction pathway, in various carbon-carbon bond-forming reactions. Theoretical investigation revealed key elements to achieve the multiple selectivity control, which would provide a basis for the development of related and more effective catalytic systems.

DOI： 10.5059/yukigoseikyokaishi.79.406

CiNii Research

Catalytic asymmetric synthesis of 5-membered alicyclic α-quaternary β-amino acids via [3 + 2]-photocycloaddition of α-substituted acrylates Reviewed

Yuto Kimura, Daisuke Uraguchi, Takashi Ooi

Organic & Biomolecular Chemistry Vol. 19 ( 8 ) page： 1744 - 1747 2021.3

Catalytic Asymmetric Synthesis of 5-Membered Alicyclic α-Quaternary β-Amino Acids via [3+2]-Photocycloaddition of α-Substituted Acrylates Reviewed

Organic & Biomolecular Chemistry 2021.2

o-Quinone Methide with Overcrowded Olefin Component as a Dehydridation Catalyst under Aerobic Photoirradiation Conditions Reviewed

CHEMICAL SCIENCE Vol. 12 page： 2778-2783 2021.1

Mannich-type allylic C-H functionalization of enol silyl ethers under photoredox-thiol hybrid catalysis Reviewed

Tsubasa Nakashima, Kohsuke Ohmatsu, Takashi Ooi

ORGANIC & BIOMOLECULAR CHEMISTRY Vol. 19 ( 1 ) page： 141 - 145 2021.1

Hybrid Catalysis of 8-Quinolinecarboxaldehyde and Br?nsted Acid for Efficient Racemization of α-Amino Amides and Its Application in Chemoenzymatic Dynamic Kinetic Resolution Reviewed

HETEROCYCLES Vol. 2021 ( 103 ) page： xxxx-xxxx 2021

Urea as a Redox-Active Directing Group under Asymmetric Photocatalysis of Iridium-Chiral Borate Ion Pairs Reviewed

Uraguchi Daisuke, Kimura Yuto, Ueoka Fumito, Ooi Takashi

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY Vol. 142 ( 46 ) page： 19462 - 19467 2020.11

Redox-regulated divergence in photocatalytic addition of alpha-nitro alkyl radicals to styrenes Reviewed

Tsuchiya Yuto, Onai Ryota, Uraguchi Daisuke, Ooi Takashi

CHEMICAL COMMUNICATIONS Vol. 56 ( 75 ) page： 11014 - 11017 2020.9

Redox-Regulated Divergence in Photocatalytic Addition of α-Nitro Alkyl Radicals to Styrenes Reviewed

Yuto Tsuchiya, Ryota Onai, Daisuke Uraguchi and Takashi Ooi

Chemical Communications 2020.8

A Structurally Robust Chiral Borate Ion: Molecular Design, Synthesis, and Asymmetric Catalysis Reviewed

Uraguchi Daisuke, Ueoka Fumito, Tanaka Naoya, Kizu Tomohito, Takahashi Wakana, Ooi Takashi

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION Vol. 59 page： 11456-11461 2020.7

Non-Enzymatic Hybrid Catalysis for Stereoconversion of l-Amino Acid Derivatives to d-Isomers Reviewed

Nagato Yuya, Kiyokawa Mari, Ueki Yusuke, Kikuchi Jun, Ohmatsu Kohsuke, Terada Masahiro, Ooi Takashi

ASIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 9 ( 4 ) page： 561-565 2020.4

Exploiting single-electron transfer in Lewis pairs for catalytic bond-forming reactions Reviewed

Aramaki Yoshitaka, Imaizumi Naoki, Hotta Mao, Kumagai Jun, Ooi Takashi

CHEMICAL SCIENCE Vol. 11 ( 17 ) page： 4305-4311 2020.3

Unveiling Latent Photoreactivity of Imines Reviewed

Uraguchi Daisuke, Tsuchiya Yuto, Ohtani Tsuyoshi, Enomoto Takafumi, Masaoka Shigeyuki, Yokogawa Daisuke, Ooi Takashi

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION Vol. 59 ( 9 ) page： 3665-3670 2020.2

Zwitterionic 1,2,3-Triazolium Amidate as a Catalyst for Photoinduced Hydrogen-Atom Transfer Radical Alkylation Reviewed

Ohmatsu Kohsuke, Suzuki Ryuhei, Furukawa Yukino, Sato Makoto, Ooi Takashi

ACS CATALYSIS Vol. 10 ( 4 ) page： 2627-2632 2020.2

Ion-paired Ligands for Palladium-catalyzed Allylic Alkylation under Base-free Conditions

Ohmatsu Kohsuke, Matsuyama Naho, Nagato Yuya, Ooi Takashi

Chemistry Letters Vol. 49 ( 9 ) page： 1114 - 1116 2020

Publishing type：Research paper (scientific journal) Publisher：公益社団法人日本化学会

The effectiveness of a catalytic amount of bromide ions for significantly accelerating the palladium-catalyzed allylation of carbonyl compounds with allylic carbonates is reported. In particular, the utilization of an ammonium–phosphine hybrid ligand bearing a bromide ion is uniquely effective for promoting allylation under mild, base-free conditions, thus obviating the need to use polar solvents and external strong Brønsted bases.

DOI： 10.1246/cl.200264

Inserting Nitrogen: An Effective Concept To Create Nonplanar and Stimuli-Responsive Perylene Bisimide Analogues

Hayakawa Sakiho, Kawasaki Ayumi, Hong Yongseok, Uraguchi Daisuke, Ooi Takashi, Kim Dongho, Akutagawa Tomoyuki, Fukui Norihito, Shinokubo Hiroshi

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY Vol. 141 ( 50 ) page： 19807-19816 2019.12

Cationic Organic Catalysts or Ligands in Concert with Metal Catalysts

Ohmatsu Kohsuke, Ooi Takashi

TOPICS IN CURRENT CHEMISTRY Vol. 377 ( 6 ) 2019.12

Direct allylic C-H alkylation of enol silyl ethers enabled by photoredox-Bronsted base hybrid catalysis

Ohmatsu Kohsuke, Nakashima Tsubasa, Sato Makoto, Ooi Takashi

NATURE COMMUNICATIONS Vol. 10 2019.6

Photocatalytic borylcyclopropanation of alpha-boryl styrenes

Ohtani Tsuyoshi, Tsuchiya Yuto, Uraguchi Daisuke, Ooi Takashi

ORGANIC CHEMISTRY FRONTIERS Vol. 6 ( 11 ) page： 1734-1737 2019.6

Photocatalytic Borylcyclopropanation of α-Boryl Styrenes Reviewed

Tsuyoshi Ohtani, Yuto Tsuchiya, Daisuke Uraguchi and Takashi Ooi

Org. Chem. Front. Vol. 2019 ( 6 ) page： 1734-1737 2019.6

Formal Hydroformylation of α,β-Unsaturated Carboxylic Acids under Photoexcited Ketone Catalysis Reviewed

Kailong Zhu, Tsuyoshi Ohtani, Chandra Bhushan Tripathi, Daisuke Uraguchi, and Takashi Ooi

Chem. Lett. Vol. 2019 ( 48 ) 2019

The design principle of synthetic strigolactones

Tsuchiya Yuichiro, Uraguchi Daisuke, Ooi Takashi

Regulation of Plant Growth & Development Vol. 54 ( 1 ) page： 49-53 2019

Language：English Publishing type：Research paper (scientific journal)

Strigolactones have diverse functions as plant hormones and as ecological signals to communicate with soil microbes. Strigolactones are also exploited by parasitic plants, including noxious parasitic weeds called Striga hermonthica, as germination cues that enable efficient parasitism to their host plants. Recent understanding for the mechanism of strigolactone perception by α/β-hydrolase receptors has provided opportunities to dissect the diverse functions with synthetic strigolactones. Here, we introduce the design principle of the synthetic strigolactones, which relies on a hybrid of two functions encoded in the two substructures, ABC-ring and D-ring. The principle discussed here has been applied to develop a Striga-selective suicide germination stimulant acting at femtomolar-range.

DOI： 10.18978/jscrp.54.1_49

A femto-molar range suicide germination stimulant for the parasitic plant Striga hermonthica Reviewed

Daisuke Uraguchi, Keiko Kuwata, Yuh Hijikata, Rie Yamaguchi, Hanae Imaizumi, Sathiyanarayanan AM, Christin Rakers, Narumi Mori, Kohki Akiyama, Stephan Irle, Peter McCourt, Toshinori Kinoshita, Takashi Ooi, Yuichiro Tsuchiya

Science Vol. 2018 ( 362 ) page： 1301-1305 2018.12

Chemistry of Ammonium Betaines: Application to Ion-Pair Catalysis for Selective Organic Transformations

Uraguchi Daisuke, Ooi Takashi

JOURNAL OF SYNTHETIC ORGANIC CHEMISTRY JAPAN Vol. 76 ( 11 ) page： 1144-1153 2018.11

Protonated Bis-1,2,3-triazole as an Anion-Binding Chiral Bronsted Acid for Catalytic Asymmetric Friedel-Crafts Reaction of Indoles with Imines

Furukawa Yukino, Suzuki Ryuhei, Nakashima Tsubasa, Gramage-Doria Rafael, Ohmatsu Kohsuke, Ooi Takashi

BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN Vol. 91 ( 8 ) page： 1252-1257 2018.8

Catalyst-Directed Guidance of Sulfur-Substituted Enediolates to Stereoselective Carbon-Carbon Bond Formation with Aldehydes

Uraguchi Daisuke, Yamada Kohei, Sato Makoto, Ooi Takashi

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY Vol. 140 ( 15 ) page： 5110-5117 2018.4

Catalyst-Enabled Site-Divergent Stereoselective Michael Reactions: Overriding Intrinsic Reactivity of Enynyl Carbonyl Acceptors

Uraguchi Daisuke, Shibazaki Ryo, Tanaka Naoya, Yamada Kohei, Yoshioka Ken, Ooi Takashi

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION Vol. 57 ( 17 ) page： 4732-4736 2018.4

Allenedicarboxylate as a Stereochemically Labile Electrophile for Chiral Organic Base-catalyzed Stereoselective Michael Addition

Uraguchi Daisuke, Kawai Yasutaka, Sasaki Hitoshi, Yamada Kohei, Ooi Takashi

CHEMISTRY LETTERS Vol. 47 ( 4 ) page： 594-597 2018.4

Molecular Design, Synthesis, and Asymmetric Catalysis of a Hexacoordinated Chiral Phosphate Ion Reviewed

Daisuke Uraguchi, Hitoshi Sasaki, Yuto Kimura, Takaki Ito, and Takashi Ooi

J. Am. Chem. Soc. Vol. 2018 ( 140 ) page： 2765-2768 2018.2

丸岡啓二先生に日本学士院賞

大井貴史

有機合成化学協会誌 Vol. 76 ( 6 ) page： 565-565 2018

Diastereo- and enantioselective phase-transfer alkylation of 3-substituted oxindoles with racemic secondary alkyl halides Reviewed

Kohsuke Ohmatsu, Yukino Furukawa, Mari Kiyokawa and Takashi Ooi

Chem. Commun. Vol. 2017 ( 53 ) page： 13113-13116 2017.10

Determination of the absolute configuration of compounds bearing chiral quaternary carbon centers using the crystalline sponge method

Shiho Sairenji, Takashi Kikuchi, Mohamed Ahmed Abozeid, Shinobu Takizawa, Hiroaki Sasai, Yuichiro Ando, Kohsuke Ohmatsu, Takashi Ooi and Makoto Fujita

Chem. Sci. Vol. 2017 ( 8 ) page： 5132-5136 2017.8

Photoredox Ketone Catalysis for Direct C-H Imidation and Acyloxylation of Arenes Reviewed

Chandra Bhushan Tripathi, Tsuyoshi Ohtani, Michael T. Corbett and Takashi Ooi

Chem. Sci. ( 8 ) page： 5622-5627 2017

N-Sulfonyl α-Imino Ester-Derived Chiral Oxaziridines: Catalytic Asymmetric Synthesis and Application as a Modular Chiral Organic Oxidant Reviewed

Naoya Tanaka, Ryosuke Tsutsumi, Daisuke Uraguchi,Takashi Ooi

Chem. Commun. ( 53 ) page： 6999-7002 2017

Unique Site-selectivity Control in Asymmetric Michael Addition of Azlactone to Alkenyl Dienyl Ketones Enabled by P-Spiro Chiral Iminophosphorane Catalysis Invited Reviewed

Ken Yoshioka, Kohei Yamada, Daisuke Uraguchi,Takashi Ooi

Chem. Commun. ( 53 ) page： 5495-5498 2017

Acridinium Betaine as a Single-Electron-Transfer Catalyst: Design and Application to Dimerization of Oxindoles Reviewed

Daisuke Uraguchi, Masahiro Torii, Takashi Ooi

ACS Catal. ( 7 ) page： 2765-2769 2017

Complete diastereodivergence in asymmetric 1,6-addition reactions enabled by minimal modification of a chiral catalyst Reviewed

Daisuke Uraguchi, Ken Yoshioka, Takashi Ooi

Nature Communications ( 8 ) page： 14793 2017

[5.5]-P-Spirocyclic Chiral Triaminoiminophosphorane-Catalyzed Asymmetric Hydrophosphonylation of Aldehydes and Ynones Reviewed

Daisuke Uraguchi, Takaki Ito, Yuto Kimura, Yumiko Nobori, Makoto Sato, Takashi Ooi

Bull. Chem. Soc. Jpn. ( 90 ) page： 546-555 2017

In Situ Electrophilic Activation of Hydrogen Peroxide for Catalytic Asymmetric α-Hydroxylation of 3-Substituted Oxindoles Invited Reviewed

Kohsuke Ohmatsu, Yuichiro Ando, Takashi Ooi

Synlett ( 28 ) page： 1291-1294 2017

Stereoselective Aza-Henry Reaction of 3-Nitro-Dihydro-2(1H)-Quinolones with N-BOC-Aldimines under the Catalysis of Chiral Ammonium Betaines Invited Reviewed

Daisuke Uraguchi, Masahiro Torii, Kohsuke Kato, Takashi Ooi

Heterocycles ( 94 ) page： 441-447 2017

Origin of High Regio-, Diastereo-, and Enantioselectivities in 1,6-Addition of Azlactones to Dienyl N-Acylpyrroles: A Computational Study Reviewed

Yamanaka, Masahiro; Sakata, Ken; Yoshioka, Ken; Uraguchi, Daisuke; Ooi, Takashi

J. Org. Chem. Vol. 2017 ( 82 ) page： 541-548 2017

A Modular Strategy for the Direct Catalytic Asymmetric α-Amination of Carbonyl Compound Reviewed

Kohsuke Ohmatsu, Yuichiro Ando, Tsubasa Nakashima, Takashi Ooi

Chem Vol. 1 ( 5 ) page： 802-810 2016.11

Palladium-Catalyzed Branch-Selective Decarboxylative Allylation Using Ion-Paired Ligands Reviewed

Yoshiyuki Hara, Yuya Kusano, Kohsuke Ohmatsu, and Takashi Ooi

Chem. Lett. Vol. 2016 ( 45 ) page： 552-554 2016

Anion-Stoichiometry-Dependent Selectivity Enhancement in Ion-Paired Chiral Ligand-Palladium Complex Catalyzed Enantioselective Allylic Alkylation Reviewed

Kohsuke Ohmatsu, Yoshiyuki Hara, Yuya Kusano, Takashi Ooi

Synlett Vol. 2016 ( 27 ) page： 1047-1050 2016

Multiple Absolute Stereocontrol in Pd-Catalyzed [3+2] Cycloaddition of Oxazolidinones and Trisubstituted Alkenes Using Chiral Ammonium-Phosphine Hybrid Ligands Reviewed

Naomichi Imagawa, Yuya Nagato, Kohsuke Ohmatsu, and Takashi Ooi

Bull. Chem. Soc. Jpn. Vol. 2016 ( 89 ) page： 649-656 2016

Independence from the Sequence of Single-Electron Transfer of Photoredox Process in Redox-Neutral Asymmetric Bond-Forming Reaction Reviewed

Tomohito Kizu, Daisuke Uraguchi, and Takashi Ooi

J. Org. Chem. Vol. 2016 ( 81 ) page： 6953-6958 2016

Chiral Ammonium Betaine-Catalyzed Asymmetric Mannich-Type Reaction of Oxindoles Reviewed

Masahiro Torii, Kohsuke Kato, Daisuke Uraguchi, and Takashi Ooi

Beilstein J. Org. Chem. Vol. 2016 ( 12 ) page： 2099-2103 2016

Vinylogy in Nitronates: Utilization of α-Aryl Conjugated Nitroolefins as a Nucleophile for Highly Stereoselective Aza-Henry Reaction Reviewed

Keigo Oyaizu, Daisuke Uraguchi, Takashi Ooi

Chem. Commun. Vol. 2015 ( 51 ) page： 4437-4439 2015

Highly E- and Enantioselective Michael Addition to Electron-deficient Internal Alkynes under the Catalysis of Chiral Iminophosphorane Reviewed

Daisuke Uraguchi, Kohei Yamada, Takashi Ooi

Angew. Chem. Int. Ed. Vol. 2015 ( 54 ) page： 9954-9957 2015

Catalytic Asymmetric Cyanation of Alkylideneindolenines Generated from Sulfonylalkylindoles Reviewed

Kohsuke Ohmatsu, Yukino Furukawa, Daigo Nakaguro, and Takashi Ooi

Chem. Lett. Vol. 2015 ( 44 ) page： 1350-1352 2015

Enantioselective Reductive Multicomponent Coupling Reactions between Isatins and Aldehydes Reviewed

Matthew A. Horwitz, Naoya Tanaka, Takuya Yokosaka, Daisuke Uraguchi, Jeffrey S. Johnson, and Takashi Ooi

Chem. Sci. Vol. 2015 ( 6 ) page： 6086-6090 2015

Synergistic Catalysis of Ionic Brønsted Acid and Photosensitizer for a Redox Neutral Asymmetric α-Coupling of N-Arylaminomethanes with Aldimines Reviewed

Daisuke Uraguchi, Natsuko Kinoshita, Tomohito Kizu, and Takashi Ooi

J. Am. Chem. Soc. Vol. 2015 ( 137 ) page： 13768-13771 2015

Ligand-enabled multiple absolute stereocontrol in metal-catalysed cycloaddition for construction of contiguous all-carbon quaternary stereocentres Reviewed

Kohsuke Ohmatsu, Naomichi Imagawa, Takashi Ooi

Kohsuke Ohmatsu, Naomichi Imagawa, Takashi Ooi Vol. 6 ( 1 ) page： 47-51 2014

Palladium-Catalyzed Asymmetric [3 + 2] Cycloaddition of 5-Vinyloxazolidinones with Imines Using Chiral Ammonium-Phosphine Hybrid Ligand Reviewed

Kohsuke Ohmatsu, Shinya Kawai, Naomichi Imagawa, Takashi Ooi

ACS Catal. Vol. 2014 ( 4 ) page： 4304-4306 2014

Catalytic asymmetric Payne oxidation under the catalysis of P-spiro chiral triaminoiminophosphorane: Application to the synthesis of N-sulfonyl oxaziridines Reviewed

Daisuke Uraguchi, Ryosuke Tsutsumi, Takashi Ooi

Tetrahedron Vol. 2014 ( 70 ) page： 1691-1701 2014

Asymmetric Alkylation of α-Cyanosulfones Catalyzed by Chiral 1,2,3-Triazolium Salts Reviewed

Kohsuke Ohmatsu, Yusuke Hakamata, Ayano Goto, Takashi Ooi

Heterocycles Vol. 2014 ( 88 ) page： 1661-1666 2014

Ligand-controlled E/Z selectivity and enantioselectivity in palladium-catalyzed allylation of benzofuranones with 1,2-disubstituted allylic carbonates Reviewed

Kohsuke Ohmatsu, Mitsunori Ito , Takashi Ooi

Chem. Commun. Vol. 2014 ( 50 ) page： 4554-4557 2014

Practical Preparation of Chiral N-Sulfonyl Oxaziridines by Catalytic Asymmetric Payne Oxidation Reviewed

Ryosuke Tsutsumi, Seonwoo Kim, Daisuke Uraguchi, Takashi Ooi

Synthesis (PSP article) Vol. 2014 ( 46 ) page： 871-878 2014

Enantioselective formal α-allylation of nitroalkanes through a chiral iminophosphorane-catalyzed Michael reaction-Julia-Kocienski olefination sequence Reviewed

Daisuke Uraguchi, Shinji Nakamura, Hitoshi Sasaki, Yuki Konakade, Takashi Ooi

Chem. Commun. Vol. 2014 ( 50 ) page： 3491-3493 2014

In-Situ Generation of Ion-Paired Chiral Ligands: Rapid Identification of Optimal Ligand for Palladium-Catalyzed Asymmetric Allylation Reviewed

Kohsuke Ohmatsu, Yoshiyuki Hara, Takashi Ooi

Chem. Sci. Vol. 2014 ( 5 ) page： 3645-3650 2014

Enantioselective Protonation of α-Hetero Carboxylic Acid-Derived Ketene Disilyl Acetals under Chiral Ionic Brønsted Acid Catalysis Reviewed

Daisuke Uraguchi, Tomohito Kizu, Yuki Ohira, Takashi Ooi

Chem. Commun. Vol. 2014 ( 50 ) page： 13489-13491 2014

Chiral Ammonium Betaine-Catalyzed Highly Stereoselective Aza-Henry Reaction of α-Aryl Nitromethanes with Aromatic N-Boc Imines Reviewed

Daisuke Uraguchi, Keigo Oyaizu, Haruhiro Noguchi, Takashi Ooi

Chem. Asian J. Vol. 2014 ( 10 ) page： 334-337 2014

Highly Stereoselective Michael Addition of Azlactones to Electron-Deficient Triple Bonds under P-Spiro Chiral Iminophosphorane Catalysis: Importance of Protonation Pathway Reviewed

Uraguchi, Daisuke; Ueki, Yusuke; Sugiyama, Atsushi; Ooi, Takashi

Chem. Sci. Vol. 4 page： in press 2013.1

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

A catalyst-controlled, geometrically divergent asymmetric Michael addition of azlactones to methyl propiolate has been achieved under the catalysis of P-spiro chiral triaminoiminophosphoranes. An uncommon O-protonation of the intermediary allenic enolate is proposed to rationalize geometric control and its validity is proven by the development of highly Z- and enantioselective Michael addition of azlactones to cyanoacetylene with broad substrate scope.

DOI： 10.1039/C2SC22027J

Carbene Transfer from Triazolylidene Gold Complexes as a Potent Strategy for Inducing High Catalytic Activity Reviewed

Daniel Canseco-Gonzalez, Ana Petronilho, Helge Mueller-Bunz, Kohsuke Ohmatsu, Takashi Ooi, Martin Albrecht

J. Am. Chem. Soc. Vol. 135 ( 35 ) page： 13193-13203 2013

Asymmetric Substitution at the Tetrasubstituted Chiral Carbon: Catalytic Ring-Opening Alkylation of Racemic 2,2-Disubstituted Aziridines with 3-Substituted Oxindoles Reviewed

Kohsuke Ohmatsu, Yuichiro Ando, Takashi Ooi

J. Am. Chem. Soc. Vol. 135 ( 50 ) page： 18706-18709 2013

Catalytic Asymmetric Oxidation of N-Sulfonyl Imines with Hydrogen Peroxide-Trichloroacetonitrile System Reviewed

Daisuke Uraguchi, Ryosuke Tsutsumi, and Takashi Ooi

J. Am. Chem. Soc. Vol. 2013 ( 135 ) page： 8161-8164 2013

Exploiting the Modularity of Ion-Paired Chiral Ligands for Palladium-Catalyzed Enantioselective Allylation of Benzofuran-2(3H)-ones Reviewed

Kohsuke Ohmatsu, Mitsunori Ito, Tomoatsu Kunieda, and Takashi Ooi

J. Am. Chem. Soc. Vol. 135 ( 2 ) page： 590–593 2012.12

Highly Regio-, Diastereo-, and Enantioselective 1,6- and 1,8-Additions of Azlactones to Di- and Trienyl N-Acylpyrroles Reviewed

Uraguchi, Daisuke; Yoshioka, Ken; Ueki, Yusuke; Ooi, Takashi

J. Am. Chem. Soc. Vol. 134 ( 47 ) page： 19370–19373 2012.11

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

A vinylog of Michael addition (1,6-addition) of azlactones to δ-substituted dienyl N-acylpyrroles has been developed with virtually complete 1,6-, diastereo-, and enantioselectivities by means of chiral P-spiro triaminoiminophosphorane as a catalyst. This system has been successfully extended to an unprecedented bis-vinylog of Michael addition (1,8-addition) of azlactones to ζ-substituted trienyl N-acylpyrroles with high levels of regio- and stereocontrol.

DOI： 10.1021/ja310209g

Chiral Ionic Brønsted Acid-Achiral Brønsted Base Synergistic Catalysis for Asymmetric Sulfa-Michael Addition to Nitroolefins Reviewed

Uraguchi, Daisuke; Kinoshita, Natsuko; Nakashima, Daisuke; Ooi, Takashi

Chem. Sci. Vol. 3 ( 11 ) page： 3161-3164 2012.7

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

A highly enantioselective sulfa-Michael addition to aromatic and aliphatic nitroolefins is achieved under the synergistic catalysis of chiral, ionic Brønsted acid homo-1b·HBArF and 2,6-lutidine. The potential utility of this new method is clearly demonstrated by its application to the syntheses of a novel, optically active taurine derivative and β-sultam.

DOI： 10.1039/C2SC20698F

Nitroolefins as a Nucleophilic Component for Highly Stereoselective Aza-Henry Reaction under the Catalysis of Chiral Ammonium Betaines Reviewed

Uraguchi, Daisuke; Oyaizu, Keigo; Ooi, Takashi

Chem. Eur. J. Vol. 18 ( 27 ) page： 8306–8309 2012.7

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

Vinylogous nitronate was successfully generated from β,β-disubstituted nitroolefins for achieving a highly regio-, diastereo-, and enantioselective aza Henry reaction under the influence of chiral ammonium betaine of type 1 as an organic-base catalyst. The present approach greatly expands the synthetic utility of nitroolefins in the development of carbon-carbon bond-forming reactions.

DOI： 10.1002/chem.201201259

Catalytic Asymmetric Mannich-Type Reactions of α-Cyano α-Sulfonyl Carbanions Invited Reviewed

Ohmatsu, Kohsuke; Goto, Ayano; Ooi, Takashi

Chem. Commun. Vol. 48 ( 64 ) page： 7913-7915 2012.5

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

An efficient asymmetric Mannich-type reaction of α-cyano α-sulfonyl carbanions has been achieved by exploiting the structural modularity and anion-recognition ability of chiral 1,2,3-triazolium ions. This protocol has proven to be applicable to a variety of N-Boc imines and cyanosulfones, affording β-amino α-cyanosulfones in excellent yields with high stereoselectivities.

DOI： 10.1039/C2CC32398B

Catalytic Asymmetric Ring Openings of Meso and Terminal Aziridines with Halides Mediated by Chiral 1,2,3-Triazolium Silicates Reviewed

Ohmatsu, Kohsuke; Hamajima, Yuta; Ooi, Takashi

J. Am. Chem. Soc. Vol. 134 ( 21 ) page： 8794–8797 2012.5

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

Catalytic asymmetric chloride and bromide ring openings of meso aziridines with trimethylsilyl halides have been developed using modular chiral 1,2,3-triazolium chlorides as catalysts. Control experiments suggest the reaction pathway involving hypervalent silicate ions as reactive intermediates. The application of this system to the efficient kinetic resolution of terminal aziridines is also reported.

DOI： 10.1021/ja3028668

Ionic Nucleophilic Catalysis of Chiral Ammonium Betaines for Highly Stereoselective Aldol Reaction from Oxindole-Derived Vinylic Carbonates Reviewed

Uraguchi, Daisuke; Koshimoto, Kyohei; Ooi, Takashi

J. Am. Chem. Soc. Vol. 134 ( 16 ) page： 6972–6975 2012.4

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

A new strategy for developing stereoselective bond-forming reactions is introduced; it takes advantage of the ionic nucleophilic catalysis of chiral ammonium betaines to utilize vinylic esters simultaneously as the enolate precursor and the acylating agent for coupling with electrophiles. Its synthetic utility is clearly demonstrated by the realization of a highly diastereo- and enantioselective aldol reaction from oxindole-derived vinylic carbonates.

DOI： 10.1021/ja3022939

Base-Catalyzed Direct Aldolization of α-Alkyl-α-Hydroxy Trialkyl Phosphonoacetates Reviewed

Corbett, Michael; Uraguchi, Daisuke; Ooi, Takashi; Johnson, Jeffrey

Angew. Chem. Int. Ed. Vol. 51 ( 19 ) page： 4685–4689 2012.4

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

Pass the P: Catalytic direct aldol addition of α-hydroxy trialkyl phosphonacetates to aldehydes affords α-hydroxy-β-phosphonyloxy ester products. The fully substituted glycolate enolate intermediate is generated in situ under mild conditions by a [1,2] phosphonate-phosphate rearrangement. High enantioselectivity and dramatic enhancement of reaction diastereocontrol is realized by the application of chiral iminophosphorane catalysts.

DOI： 10.1002/anie.201200559

Ion-paired chiral ligands for asymmetric palladium catalysis Reviewed

Ohmatsu, Kohsuke; Ito, Mitsunori; Kunieda, Tomoatsu; Ooi, Takashi

Nature Chemistry Vol. 4 page： 473–477 2012.4

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

Conventional chiral ligands rely on the use of a covalently constructed, single chiral molecule embedded with coordinative functional groups. Here, we report a new strategy for the design of a chiral ligand for asymmetric transition-metal catalysis; our approach is based on the development of an achiral cationic ammonium-phosphine hybrid ligand paired with a chiral binaphtholate anion. This ion-paired chiral ligand imparts a remarkable stereocontrolling ability to its palladium complex, which catalyses a highly enantioselective allylic alkylation of α-nitrocarboxylates. By exploiting the possible combinations of the achiral onium entities with suitable coordinative functionalities and readily available chiral acids, this approach should contribute to the development of a broad range of metal-catalysed, stereoselective chemical transformations.

DOI： 10.1038/nchem.1311

Highly Stereoselective Catalytic Conjugate Addition of Acyl Anion Equivalent to Nitroolefins Reviewed

Uraguchi, Daisuke; Ueki, Yusuke; Ooi, Takashi

Chem. Sci. Vol. 3 ( 3 ) page： 842-845 2011.11

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

Highly enantioselective conjugate addition of 2-unsubstituted azlactone 3 to various nitroolefins 4 was accomplished by the selective utilization of supramolecularly assembled, chiral tetraaminophosphonium aryloxide-arylhydroxide 1a·[2a]2 as a requisite catalyst. The key to this achievement is the polarity dependence of the molecular associations of type 1·[2]n and the crucial role of the proximal arylhydroxide 2 as a proton donor. The present method offers an attractive route to various optically active amino carbonyl compounds including β2-amino acids.

DOI： 10.1039/C1SC00678A

Enantioselective Aza-Michael Addition to Conjugated Nitroenynes Catalyzed by Chiral Arylaminophosphonium Barfates Invited Reviewed

Uraguchi, Daisuke; Kinoshita, Natsuko; Kizu, Tomohito; Ooi, Takashi

Synlett ( 9 ) page： 1265-1267 2011.4

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

Enantioselective aza-Michael addition to conjugated nitroenynes has been developed. P-Spiro heterochiral arylaminophosphonium barfate 1bBArF effectively catalyzes the reaction, and the corresponding conjugate adducts, β-amino homopropargylic nitro compounds, are obtained in good chemical yields with high enantioselectivities.

DOI： 10.1055/s-0030-1260541

Chiral 1,2,3-Triazoliums as New Cationic Organic Catalysts with Anion-Recognition Ability: Application to Asymmetric Alkylation of Oxindoles Reviewed

Ohmatsu, Kohsuke, Kiyokawa, Mari, Ooi, Takashi

J. Am. Chem. Soc. ( 133 ) page： 1307–1309 2011

Controlled Assembly of Chiral Tetraaminophosphonium Aryloxide Arylhydroxide(s) in Solution Reviewed

Uraguchi, Daisuke; Ueki, Yusuke; Ooi, Takashi

Angew. Chem. Int. Ed. ( 50 ) page： 3681–3683 2011

Precise Control of Spontaneous Molecular Assembly of Chiral Tetraaminophosphonium Aryloxide-Arylhydroxide(s) in Solution Reviewed

Uraguchi, Daisuke; Ueki, Yusuke; Ooi, Takashi

Angew. Chem. Int. Ed. Vol. 2011 ( 50 ) page： 3681-3683 2011

Development of P-Spiro Chiral Aminophosphonium Salts as a New Class of Versatile Organic Molecular Catalyst Reviewed

Uraguchi, Daisuke; Ooi, Takashi

有機合成化学協会誌 Vol. 68 page： 1185-1194 2010.11

Flexible Synthesis, Structural Determination, and Synthetic Application of a New C1-Symmetric Chiral Ammonium Betaine Reviewed

Uraguchi, Daisuke; Koshimoto, Kyohei; Ooi, Takashi

Chem. Commun. Vol. 46 page： 300-302 2010

Development of D2-Symmetric Chiral Tetraaminophosphonium Salts as a Catalyst for Asymmetric Phase-Transfer Reactions Invited Reviewed

Uraguchi, Daisuke; Ooi, Takashi

Vol. 39 page： 42-48 2010

Development of Ion-Pair Cooperative Asymmetric Catalyses of Chiral Phosphonium Salts Possessing an Organic Anion Invited Reviewed

Ueki, Yusuke; Uraguchi, Daisuke; Ooi, Takashi

Vol. 52 page： 509-514 2010

Catalytic Asymmetric Protonation of α-Amino Acid-Derived Ketene Disilyl Acetals Using P-Spiro Diaminodioxaphosphonium Barfates as Chiral Proton Reviewed

Uraguchi, Daisuke; Kinoshita, Natsuko; Ooi, Takashi

J. Am. Chem. Soc. Vol. 132 page： 12240-12242 2010

Catalytic Asymmetric Direct Henry Reaction of Ynals: Short Syntheses of (2S,3R)-(+)-Xestoaminol C and (–)-Codonopsinines Reviewed

Uraguchi, Daisuke; Nakamura, Shinji; Ooi, Takashi

Angew. Chem. Int. Ed. Vol. 49 page： 7562–7565 2010

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

Triple for all: Various optically active anti-β-nitro propargylic alcohols are synthesized by the catalytic stereoselective addition of nitroalkanes to ynals (the direct Henry reaction of ynals). The utilization of the rich chemistry of carbon–carbon triple bond allows rapid access to three natural products.

Chiral Ammonium Betaines as an Ionic Nucleophilic Catalyst Reviewed

Uraguchi, Daisuke; Koshimoto, Kyohei; Miyake, Shuhei; Ooi, Takashi

Angew. Chem. Int. Ed. Vol. 49 page： 5567-5569 2010

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

Catalyst debut: The chiral ammonium betaine 1 has been successfully applied to the asymmetric Steglich rearrangement as an ionic nucleophilic catalyst. The catalyzed reaction results in record levels of product enantioselectivity, and has a broad substrate scope. M.S.=molecular sieves, Troc=2,2,2-trichloroethoxycarbonyl.

Catalytic Asymmetric Hydrophosphonylation of Ynones Invited

Uraguchi, Daisuke; Ito, Takaki; Nakamura, Shinji; Ooi, Takashi

Chemical Science Vol. 1 page： 488-490 2010

Performance of C1-symmetric chiral ammonium betaines as a catalyst for the enantioselective Mannich-type reaction of α-nitrocarboxylates Invited Reviewed

Uraguchi, Daisuke; Koshimoto, Kyohei; Sanada, Chisato; Ooi, Takashi

Tetrahedron: Asymmetry Vol. 21 page： 1189-1190 2010

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

The catalytic performance of C1-symmetric chiral ammonium betaines in the enantioselective direct Mannich-type reaction of α-nitrocarboxylates with N-Boc imines has been investigated. The most effective catalyst structure has been identified; this provides a reliable synthetic route to a variety of enantiomerically enriched α-tetrasubstituted α,β-diamino acid derivatives.

Phase-Transfer-Catalyzed Asymmetric Alkylation of α-Benzoyloxy-β-keto Esters: Stereoselective Construction of Congested 2,3-Dihydroxycarboxylic Acid Esters Reviewed

Hashimoto, Takuya; Sasaki, Keigo; Fukumoto, Kazuhiro; Murase, Yuichi; Abe, Naoyuki; Ooi, Takashi; Maruoka, Keiji

Chem. Asian J. Vol. 5 page： 562-570 2010

Language：English Publishing type：Research paper (scientific journal)

Highly enantioselective phase-transfer-catalyzed alkylation of tert-butyl 2-benzoyloxy-3-oxobutanoate was realized by the use of an N-spiro chiral quaternary ammonium salt, as a complementary approach to the asymmetric hydroxylation of -alkyl--keto esters. The synthetic utility of the alkylated compounds is highlighted by the diastereoselective reduction and alkylation of the remaining ketone moiety to give various enantiomerically enriched congested 2,3-dihydroxycarboxylic acid esters.

Performance of C1-symmetric chiral ammonium betaines as a catalyst for the enantioselective Mannich-type reaction of α-nitrocarboxylates Reviewed

Uraguchi, Daisuke; Koshimoto, Kyohei; Sanada, Chisato; Ooi, Takashi

Tetrahedron: Asymmetry Vol. 21 page： 1189-1190 2010

Diastereo- and Enantioselective Direct Henry Reaction of Pyruvates Mediated by Chiral P-Spiro Tetraaminophosphonium salts Reviewed

Uraguchi, Daisuke; Ito, Takaki; Nakamura, Shinji; Sakaki, Sawako; Ooi, Takashi

Chem. Lett. Vol. 38 page： 1052-1053 2009.11

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

The stereoselective direct Henry reaction of pyruvates mediated by chiral P-spiro tetraaminophosphonium salts is described. High levels of diastereo- and enantioselectivities have been achieved by the use of L-valine-derived (P,S)-2e bearing para-chlorophenyl groups as a precatalyst.

*Chiral Organic Ion Pair Catalysts Assembled Through a Hydrogen-Bonding Network Reviewed

Uraguchi, Daisuke; Ueki, Yusuke; Ooi, Takashi

Science Vol. 326 page： 120-123 2009.10

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

Research to develop structurally discrete, chiral supramolecular catalysts for asymmetric organic transformations has met with limited success. Here, we report that a chiral tetraaminophosphonium cation, two phenols, and a phenoxide anion appear to self-assemble into a catalytically active supramolecular architecture through intermolecular hydrogen bonding. The structure of the resulting molecular assembly was determined in the solid state by means of x-ray diffraction analysis. Furthermore, in solution the complex promotes a highly stereoselective conjugate addition of acyl anion equivalents to {alpha},β-unsaturated ester surrogates with a broad substrate scope. All structural components of the catalyst cooperatively participate in the stereocontrolling event.

Chiral Arylaminophosphonium Barfates as a New Class of Charged Brønsted Acid for the Enantioselective Activation of Nonionic Lewis Bases Reviewed

Daisuke Uraguchi, Daisuke Nakashima and Takashi Ooi

J. Am. Chem. Soc. Vol. 131 ( 21 ) page： 7242-7243 2009.5

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

Heterochiral [7.7]-P-spirocyclic arylaminophosphonium barfates have been designed as a novel charged, cationic Brønsted acid catalyst, and their catalytic and stereocontrolling abilities have been clearly demonstrated in the development of the unprecedented, highly enantioselective conjugate addition of arylamines to nitroolefins. This study uncovers a new function of chiral tetraaminophosphonium cations and its potential synthetic utility, thereby providing a new avenue to the molecular design of chiral charged Brønsted acid catalysts and their applications.

Asymmetric Synthesis of α,α-Disubstituted-α-Amino Acids via Enantioselective Alkylation of Azlactones under Biphasic Conditions Using P-Spiro Chiral Tetraaminophosphonium Salts as a Phase-Transfer Catalyst Invited Reviewed

Uraguchi, Daisuke; Asai, Yoshihiro; Seto, Yuki; Ooi, Takashi

Synlett ( 4 ) page： 658-660 2009.2

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

Highly enantioselective alkylation of azlactones derived from α-amino acids has been achieved under solid-liquid phase-transfer conditions using P-spiro chiral tetraaminophosphonium salt as a catalyst. The resulting alkylated azlactones can be readily converted into the corresponding α,α-disubstituted α-amino acids through simple acidic hydrolysis.

Generation of Chiral Phosphonium Dialkyl Phosphite as a Highly Reactive P-Nucleophile: Application to Asymmetric Hydrophosphonylation of Aldehydes Reviewed

Uraguchi, Daisuke; Ito, Takaki; Ooi, Takashi

J. Am. Chem. Soc. Vol. 131 ( 11 ) page： 3836–3837 2009.2

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

The generation of chiral tetraaminophosphonium dialkyl phosphite has been detected by low-temperature NMR analysis, and its synthetic potential as a remarkably reactive P-nucleophile has been successfully demonstrated by its application to the establishment of highly efficient and enantioselective hydrophosphonylation of various aldehydes. A systematic evaluation of the organic-base-dependent generation of the requisite ion pair and its reactivity and selectivity as a P-nucleophile reveals that the structure of the cationic conjugate acid of the base is a key element both for substantial generation of phosphite anions with prominent nucleophilicity and for rigorous stereocontrol. This study provides not only experimental demonstration of the importance of the phosphite tautomer in the PC bond formation process but also a general yet valuable framework for the molecular design of even superior chiral organic base catalysts.

Phase-Transfer-Catalyzed Enantioselective Alkylation of α-Benzoyloxy-β-Keto Ester Invited Reviewed

Takuya Hashimoto, Keigo Sasaki, Kazuhiro Fukumoto, Yuichi Murase, Takashi Ooi, Keiji Maruoka

Synlett ( 4 ) page： 661-663 2009.2

*Site-directed Asymmetric Quaternization of a Peptide Backbone at C-Terminal Azlactone Reviewed

Uraguchi, Daisuke; Asai, Yoshihiro; Ooi, Takashi

Angew. Chem. Int. Ed. Vol. 48 ( 3 ) page： 733-737 2009.1

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

Dual-purpose activation: Peptide C-terminal azlactones I undergo stereoselective alkylation with high efficiency by the use of a newly devised chiral tetraaminophosphonium salt as a phase-transfer catalyst (PTC), and the alkylated azlactone products II can be employed directly for peptide ligation (see scheme, LG=leaving group). In this way, a wide range of chiral quaternary -amino acid residues can be incorporated at specific sites of a peptide strand.

Al Lewis acid-catalyzed regiodivergent 1,2-rearrangement of a-siloxy aldehydes: scope and mechanism Reviewed

Kohsuke Ohmatsu, Takayuki Tanaka, Takashi Ooi, Keiji Maruoka

Tetrahedron Vol. 65 page： 7516-7522 2009

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

Regiodivergent 1,2-rearrangement of a-siloxy aldehydes bearing a-aryl and a-alkyl substituents into a-siloxy ketones has been realized by using different Al Lewis acid catalyst/solvent systems. The scope of this unprecedented protocol has been investigated with various substrates, clearly demonstrating its utility for the selective synthesis of two structural isomers from one substrate. Controlled experiments proved that the regiodivergency resulted from the switch of the migrating group.

*Chiral Ammonium Betaines: A Bifunctional Organic Base Catalyst for Asymmetric Mannich-type Reaction of α-Nitrocarboxylates Reviewed

Uraguchi, Daisuke; Koshimoto, Kyohei; Ooi, Takashi

J. Am. Chem. Soc. Vol. 130 ( 33 ) page： 10878-10879 2008.7

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

A chiral ammonium betaine, an intramolecular ion-pairing quaternary ammonium aryloxide, has been designed and its vast potential as an enantioselective organic base catalyst has been successfully demonstrated in the highly enantioselective direct Mannich-type reaction of α-substituted α-nitrocarboxylates with various N-Boc imines. The present study provides a conceptually new approach toward the design of bifunctional, chiral quaternary ammonium salts and their utilizations as a homogeneous organic molecular catalyst.

Complete Switch of Migratory Aptitude in Aluminum-Catalyzed 1,2-Rearrangement of Differently α,α-Disubstituted α-Siloxy Aldehydes Reviewed

Ohmatsu, Kohsuke; Tanaka, Takayuki; Ooi, Takashi; Maruoka, Keiji

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION Vol. 47 ( 28 ) page： 5203-5206 2008.6

Language：English Publishing type：Research paper (scientific journal)

Regiodivergent 1,2-rearrangement of alpha-siloxy aldehydes bearing alpha-aryl and alpha-alkyl substituents into alpha-siloxy ketones has been realized by using different Al Lewis acid catalyst/solvent systems. The scope of this unprecedented protocol has been investigated with various substrates, clearly demonstrating its utility for the selective synthesis of two structural isomers from one substrate.

Synthesis of Chiral Tetraaminophosphonium Chlorides from N-BOC α-Amino Acid Esters Invited Reviewed

Uraguchi, Daisuke; Sakaki, Sawako; Ueki, Yusuke; Ito, Takaki; Ooi, Takashi

Heterocycles Vol. 76 page： 1081-1085 2008

*Chiral Tetraaminophosphonium Carboxylate-Catalyzed Direct Mannich-Type Reaction Reviewed

Uraguchi, Daisuke; Ueki, Yusuke; Ooi, Takashi

J. Am. Chem. Soc. Vol. 130 page： 14088–14089 2008

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

The cooperative asymmetric catalysis of chiral tetraaminophosphonium carboxylate (P,S)-1·OCOR has been established, and its synthetic utility has been successfully demonstrated by application to the highly enantioselective direct Mannich-type reaction of azlactones with N-sulfonyl imines. The present study stimulates the cultivation of the potential of the chiral quaternary onium salt catalysis by the structural modification of organic anion.

光学活性な炭素の三角形を作る―Corey-Chaykovsky反応と親電子剤活性化法の組み合わせ Invited

浦口大輔、大井貴史

化学 Vol. 63 page： 66-67 2008

Recent advances in asymmetric phase-transfer catalysis Reviewed

Ooi, Takashi; Maruoka, Keiji

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION Vol. 46 ( 23 ) page： 4222-4266 2007

Development and Applications of C2-Symmetric, Chiral, Phase-Transfer Catalysts Invited Reviewed

Ooi, Takashi; Maruoka, Keiji

Aldrichimia Acta Vol. 40 page： 77-86 2007

*Chiral Tetraaminophosphonium Salt-Mediated Asymmetric Direct Henry Reaction Reviewed

Uraguchi, Daisuke; Sakaki, Sawako; Ooi, Takashi

J. Am. Chem. Soc. Vol. 129 page： 12392-12393 2007

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

A chiral tetraaminophosphonium salts possessing the phosphorus-centered [5.5]-spirocyclic core have been designed and synthesized in a single step from L-valine-derived diamine. The three-dimensional molecular structure was successfully verified by the single-crystal X-ray diffraction analysis, which also identified a secondary interaction between the phosphonium cation and chloride ion via double hydrogen-bonding. The potential of this novel onium salt as a chiral organic molecular catalyst has been demonstrated in an application to asymmetric direct Henry reaction.

Design of chiral organocatalysts for practical asymmetric synthesis of amino acid derivatives Invited Reviewed

Maruoka, Keiji; Ooi, Takashi; Kano, Taichi

CHEMICAL COMMUNICATIONS ( 15 ) page： 1487-1495 2007

Catalytic Asymmetric Rearrangement of α,α-Disubstituted α-Siloxy Aldehydes to Optically Active Acyloins Using Axially Chiral Organoaluminum Lewis Acids Reviewed

Ooi, Takashi; Ohmatsu, Kohsuke; Maruoka, Keiji

J. Am. Chem. Soc. Vol. 129 page： 2410-2411 2007

Language：English Publishing type：Research paper (scientific journal)

A catalytic asymmetric rearrangement of alpha,alpha-dialkyl-alpha-siloxy aldehydes has been developed based on the design of a stereochemically defined, axially chiral organoaluminum Lewis acid. The scope of this unprecedented stereoselective rearrangement has been investigated with representative substrates, in which impressive kinetic resolution of racemic, alpha,alpha-disubstituted alpha-siloxy aldehydes has also been achieved. These results clearly demonstrate the utility of the present approach for the catalytic enantioselective synthesis of various acyloins and tertiary alpha-hydroxy aldehydes not readily accessible by the previously known asymmetric methodologies.

Advantage of in situ generation of N-arylsulfonyl imines from α-amide sulfones in the phase-transfer-catalyzed asymmetric Strecker reaction Reviewed

Ooi, Takashi; Uematsu, Yukitaka; Fujimoto, Jun; Fukumoto, Kazuhiro; Maruoka, Keiji

Tetrahedron Lett. Vol. 48 page： 1337-1340 2007

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

Highly efficient, catalytic enantioselective synthesis of N-arylsulfonyl α-amino nitriles from the corresponding α-amido sulfones has been achieved under toluene–aqueous potassium cyanide biphasic conditions using chiral quaternary ammonium iodide (R,R,R)-1 as an effective phase-transfer catalyst. This Strecker synthesis involving the in situ generation of the reactive N-sulfonyl imines is advantageous for the cyanation of the substrates having primary and secondary alkyl substituents.

Practical Stereoselective Synthesis of -Branched -Amino Acids through Efficient Kinetic Resolution in the Phase-Transfer-Catalyzed Asymmetric Alkylations Reviewed

Ooi, Takashi; Kato, Daisuke; Inamura, Koji; Ohmatsu, Kohsuke; Maruoka, Keiji

Org. Lett. Vol. 9 ( 20 ) page： 3945-3948 2007

Language：English Publishing type：Research paper (scientific journal)

Phase-transfer-catalyzed alkylation of glycinate Schiff base with racemic secondary alkyl halides proceeded with excellent levels of syn- and enantioselectivities under the influence of chiral quaternary ammonium bromide 1d and 18-crown-6. The alkylation product can be selectively converted to the corresponding anti isomer, allowing the preparation of all the stereoisomers of -alkyl--amino acid derivatives, an extremely valuable chiral building block.

Highly diastereo- and enantioselective formal conjugate addition of nitroalkanes to nitroalkenes by chiral ammonium bifluoride catalysis. Reviewed

Ooi, Takashi; Takada, Saki; Doda, Kanae; Maruoka, Keiji

Angew. Chem., Int. Ed. Vol. 45 page： 7606-7608 2006

Language：English Publishing type：Research paper (scientific journal)

An efficient catalysis of new chiral quaternary ammonium bifluoride in combination with silyl nitronates has been successfully utilized for achieving the highly diastereo- and enantioselective formal conjugate addition of nitroalkanes to nitroalkenes. This unique catalytic asymmetric protocol provides a reliable access to various 1,3-dinitro compounds bearing stereochemically defined two consecutive stereocenters, which serve as a versatile chiral building block in organic synthesis.

Asymmetric phase-transfer catalysis of homo- and heterochiral quaternary ammonium salts: development and application of conformationally flexible chiral phase-transfer catalysts. Reviewed

Ooi, Takashi; Uematsu, Yukitaka; Kameda, Minoru; Maruoka, Keiji

Tetrahedron Vol. 62 page： 11425-11436 2006

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

Inspired by the considerable difference of catalytic activity and stereocontrolling ability between the conformationally rigid, homo- and heterochiral quaternary ammonium bromides 1, conformationally flexible, N-spiro chiral quaternary ammonium bromides of type 4 have been designed and synthesized. Reliable procedures for the preparation of the appropriately substituted biphenyl subunits have been established by the repeated use of ortho magnesiation–halogenation as a key synthetic tool. The relationship between the structure of achiral biphenyl moiety and the reactivity and selectivity of 4 has been evaluated in the asymmetric alkylation of glycinate Schiff base 2 under typical phase-transfer conditions, leading to the identification of 4l as an optimal catalyst structure to exhibit an excellent enantiocontrol in the reactions with various alkyl halides. The molecular structure of 4l was determined by X-ray crystallographic analysis and its unique behavior in solution was examined by a variable-temperature 1H NMR study. These investigations uncovered that the observed high chiral efficiency originated from the efficient asymmetric phase-transfer catalysis of homochiral-4l, which rapidly equilibrated with heterochiral-4l of low catalytic activity and stereoselectivity.

Asymmetric synthesis of α-acyl-γ-butyrolactones possessing all-carbon quaternary stereocenters by phase-transfer-catalyzed alkylation. Reviewed

Ooi, Takashi; Miki, Takashi; Fukumoto, Kazuhiro; Maruoka, Keiji

Adv. Synth. Catal. Vol. 348 page： 1539-1542 2006

Language：English Publishing type：Research paper (scientific journal)

The enantioselective construction of all-carbon quaternary stereocenters on -acyl--butyrolactones has been achieved by the N-spiro chiral quaternary ammonium bromide 1-catalyzed alkylation under mild phase-transfer conditions. The resulting -alkylated keto lactones serve as valuable chiral building blocks in organic synthesis as clearly demonstrated by the facile conversion to optically active ,-dialkyl--amino acid derivatives via Schmidt rearrangement.

Construction of Enantiomerically Enriched Tertiary α-Hydroxycarboxylic Acid Derivatives by Phase-Transfer-Catalyzed Asymmetric Alkylation of Diaryloxazolidin-2,4-diones Reviewed

Takashi, Ooi; Kazuhiro, Fukumoto; Keiji, Maruoka

Angew. Chem., Int. Ed. Vol. 45 page： 3839-3842 2006

Language：English Publishing type：Research paper (scientific journal)

Catalytic, highly enantioselective alkylation of 3,5-diaryloxazoline-2,4-diones has been accomplished under mild phase-transfer conditions using designer chiral quaternary ammonium bromide as catalyst. This catalytic asymmetric glycolate alkylation procedure establishes chiral quaternary carbon centers, and provides a practical access to various optically active tertiary alpha-hydroxy-alpha-arylcarboxylic acid derivatives.

Highly enantioselective monoalkylation of p-chlorobenzaldehyde imine of glycine tert-butyl ester under mild phase-transfer conditions.

Ooi, Takashi; Arimura, Yuichiro; Hiraiwa, Yukihiro; Yuan, Lin Ming; Kano, Taichi; Inoue, Toru; Matsumoto, Jun; Maruoka, Keiji

Tetrahedron: Asym. Vol. 17 page： 603-606 2006

Language：English Publishing type：Research paper (scientific journal)

The selective monoalkylation of glycine tert-butyl ester aldimine Schiff base 3 has been realized in high chemical yield with excellent enantioselectivity under mild liquid–liquid phase-transfer conditions by the use of binaphthyl-derived chiral quaternary ammonium bromides 7 and 8 as catalysts. This achievement demonstrates that 3 can be used as a cost-effective substrate for the preparation of optically active α-alkyl-α-amino acid derivatives by chiral phase-transfer catalysis.

Asymmetric Strecker Reaction of Aldimines Using Aqueous Potassium Cyanide by Phase-Transfer Catalysis of Chiral Quaternary Ammonium Salts with a Tetranaphthyl Backbone. Reviewed

Ooi, Takashi; Uematsu, Yukitaka; Maruoka, Keiji

J. Am. Chem. Soc. Vol. 128 page： 2548-2549 2006

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

The phase-transfer-catalyzed, highly enantioselective cyanation of aldimines using aqueous KCN has been realized based on the molecular design of chiral quaternary ammonium iodide bearing a stereochemically defined tetranaphthyl backbone. A wide range of aliphatic aldimines, including those having -tert-alkyl substituents, is tolerated by the present system. This study represents a novel approach for the asymmetric Strecker-type reactions, which utilizes chiral phase-transfer catalysts for practical access to various unusual, optically pure -amino acids.

Highly Enantioselective Phase-Transfer-Catalyzed Alkylation of Protected α-Amino Acid Amides toward Practical Asymmetric Synthesis of Vicinal Diamines, α-Amino Ketones, and α-Amino Alcohols. Reviewed

Ooi, Takashi; Takeuchi, Mifune; Kato, Daisuke; Uematsu, Yukitaka; Tayama, Eiji; Sakai, Daiki; Maruoka, Keiji

J. Am. Chem. Soc. Vol. 127 page： 5073-5083 2005

Language：English Publishing type：Research paper (scientific journal)

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 -branched primary alkyl halides, which provides impressive levels of kinetic resolution and double stereodifferentiation during the alkylation, allowing for two - and -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 -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 -amino ketone into both syn and anti -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 enantiomers of -amino amides including Weinreb amides readily available with enormous structural variation and also establishes a general and practical route to vicinal diamines, -amino ketones, and -amino alcohols with the desired stereochemistry.

Asymmetric Michael Addition of Silyl Nitronates to Cyclic α,β-Unsaturated Ketones Catalyzed by Chiral Quaternary Ammonium Bifluorides: Isolation and Selective Functionalization of Enol Silyl Ethers of Optically Active γ-Nitro Ketones. Reviewed

Ooi, Takashi; Doda, Kanae; Takada, Saki; Maruoka, Keiji

Tetrahedron Lett. Vol. 47 page： 145-148 2005

Language：English Publishing type：Research paper (scientific journal)

Highly enantioselective Michael addition of silyl nitronates to cyclic α,β-unsaturated ketones has been accomplished by the utilization of N-spiro C2-symmetric chiral quaternary ammonium bifluoride 1 as an efficient catalyst, offering a new route to the enol silyl ethers of optically active γ-nitro ketones. The synthetic utility of this transformation has been demonstrated by the diastereoselective derivatizations of the optically active enol silyl ethers to the corresponding α-substituted cyclic ketones having three consecutive stereochemically defined stereocenters.

N-Spiro Chiral Quaternary Ammonium Bromide Catalyzed Diastereo- and Enantioselective Conjugate Addition of Nitroalkanes to Cyclic α,β-Unsaturated Ketones under Phase-Transfer Conditions. Reviewed

Ooi, Takashi; Takada, Saki; Fujioka, Shingo; Maruoka, Keiji

Org. Lett. Vol. 7 page： 5143-5146 2005

Language：English Publishing type：Research paper (scientific journal)

Conjugate addition of various prochiral nitroalkanes to cyclic ,-unsaturated ketones was found to be efficiently catalyzed by N-spiro C2-symmetric chiral quaternary ammonium bromide 1b possessing a 3,5-bis(3,4,5-trifluorophenyl)phenyl substituent under solid-liquid phase-transfer conditions to afford the corresponding -nitro ketones in excellent chemical yields with unprecedented levels of diastereo- and enantiocontrol.

Importance of Chiral Phase-Transfer Catalysts with Dual Functions in Obtaining High Enantioselectivity in the Michael Reaction of Malonates and Chalcone Derivatives. Reviewed

Ooi, Takashi; Ohara, Daisuke; Fukumoto, Kazuhiro; Maruoka, Keiji

Org. Lett. Vol. 7 page： 3195-3197 2005

Language：English Publishing type：Research paper (scientific journal)

Highly enantioselective Michael addition of diethyl malonate to chalcone derivatives has been achieved under mild phase-transfer conditions by the successful utilization of N-spiro C2-symmetric chiral quaternary ammonium bromide 1 as a catalyst, which possesses diarylhydroxymethyl functionalities as a recognition site for the prochiral electrophile. This simple asymmetric Michael addition process was found to be quite effective for various chalcone derivatives, including those with heteroaromatic substituents.

Dramatic Rate Enhancement of Asymmetric Phase-Transfer-Catalyzed Alkylations. Reviewed

Shirakawa, Seiji; Yamamoto, Kenichiro; Kitamura, Masanori; Ooi, Takashi; Maruoka, Keiji

Angew. Chem., Int. Ed. Vol. 44 page： 625-628 2005

Asymmetric Synthesis of Functionalized Aza-Cyclic Amino Acids with Quaternary Stereocenters by a Phase-Transfer-Catalyzed Alkylation Strategy. Reviewed

Ooi, Takashi; Miki, Takashi; Maruoka, Keiji

Org. Lett. Vol. 7 page： 191-193 2005

Language：English Publishing type：Research paper (scientific journal)

Practical asymmetric synthesis of functionalized aza-cyclic -amino acid derivatives possessing quaternary stereocenters has been achieved by the phase-transfer-catalyzed alkylation of 2 or 3 using chiral quaternary ammonium bromide 1 as catalyst. Subsequent reduction and alkylation of the 3-keto carbonyl moiety of 4 proceeded with complete diastereochemical control to afford the corresponding -hydroxy aza-cyclic -amino acid derivatives having stereochemically defined consecutive quaternary carbon centers.

Stereoselective Terminal Functionalization of Small Peptides for Catalytic Asymmetric Synthesis of Unnatural Peptides Reviewed

Maruoka, Keiji; Tayama, Eiji; Ooi, Takashi

Proc. Natl. Acad. Sci. USA Vol. 101 page： 5824-5829 2004

Language：English Publishing type：Research paper (scientific journal)

The asymmetric phase-transfer catalytic alkylation of peptides has been achieved by the use of designed C2-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 ,-dialkyl--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.

Elucidation and Synthetic Utility of the Double Electrophilic Activation Phenomenon. Reviewed

Ooi, Takashi; Takahashi, Makoto; Yamada, Masao; Tayama, Eiji; Omoto, Kiyoyuki; Maruoka, Keiji

J. Am. Chem. Soc. Vol. 126 page： 1150-1160 2004

Language：English Publishing type：Research paper (scientific journal)

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 13C 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.

Meerwein-Ponndorf-Verley Alkynylation of Aldehydes: Essential Modification of Aluminum Alkoxides for Rate Acceleration and Asymmetric Synthesis. Reviewed

Ooi, Takashi; Miura, Tomoya; Ohmatsu, Kohsuke; Saito, Akira; Maruoka, Keiji

Org. Biomol. Chem. Vol. 2 page： 3312-3319 2004

Language：English Publishing type：Research paper (scientific journal)

A novel carbonyl alkynylation has been accomplished based on utilization of the Meerwein–Ponndorf–Verley (MPV) reaction system. The success of the MPV alkynylation crucially depends on the discovery of the remarkable ligand acceleration effect of 2,2-biphenol. For example, the alkynylation of chloral (2c) with the aluminium alkoxide 6(R = Ph), prepared in situ from Me3Al, 2,2-biphenol and 2-methyl-4-phenyl-3-butyn-2-ol (1a) as an alkynyl source, proceeded smoothly in CH2Cl2 at room temperature to give the desired propargyl alcohol 3ca in almost quantitative yield after 5 h stirring. The characteristic feature of this new transformation involving no metal alkynides can be visualized by the fact that the alkynyl group bearing keto carbonyl was transferred successfully to aldehyde carbonyl without any side reactions on keto carbonyl. Although the use of (S)-1,1-bi-2-naphthol and its simple analogues was found to be unsuitable for inducing asymmetry in this reaction, design of new chiral biphenols bearing a certain flexibility of the biphenyl axis led to satisfactory results in terms of enantioselectivity as well as reactivity.

「不斉有機触媒としてのキラル相間移動触媒-アミノ酸合成を中心として」 Invited

大井　貴史, 丸岡　啓二

化学と工業 Vol. 57 page： 711-715 2004

「光学活性ジエン配位子が与える新しい不斉環境」

大井　貴史

page： 134 2004

Asymmetric Organocatalysis of Structurally Well-Defined Chiral Quaternary Ammonium Fluorides. Reviewed

Ooi, Takashi; Maruoka, Keiji

Acc. Chem. Res. Vol. 37 page： 526-533 2004

Organoaluminum-Mediated Selective 1,2-Rearrangement of γ,γ-Disubstituted γ-Amino α,β-Unsaturated Carbonyl Compounds Leading to Unsymmetrically Substituted Pyrroles. Reviewed

Ooi, Takashi; Ohmatsu, Kohsuke; Ishii, Hiroki; Saito, Akira; Maruoka, Keiji

Tetrahedron Lett. Vol. 45 page： 9315-9317 2004

Language：English Publishing type：Research paper (scientific journal)

γ,γ-Dialkyl-γ-amino-α,β-unsaturated carbonyl compounds were found to undergo selective skeletal rearrangement under the influence of modified organoaluminum Lewis acid to give unsymmetrically substituted pyrroles through the rapid Paal–Knorr type cyclization upon acidic hydrolysis. This new structural reorganization of amino carbonyl compounds triggered by the 1,2-alkyl shift provides a unique entry to the synthesis of pyrroles, an important class of heterocycles with diverse biological activities.

Anti-selective Asymmetric Synthesis of β-Hydroxy-α-Amino Acid Esters by the in Situ Generated Chiral Quaternary Ammonium Fluoride-Catalyzed Mukaiyama-Type Aldol Reaction. Reviewed

Ooi, Takashi; Taniguchi, Mika; Doda, Kanae; Maruoka, Keiji

Adv. Synth. Catal. Vol. 326 page： 1073-1076 2004

Language：English Publishing type：Research paper (scientific journal)

The aldol coupling of ketene silyl acetal 2 derived from the glycinate Schiff base with aldehydes can be efficiently catalyzed by an in situ generated, chiral quaternary ammonium fluoride of type 1 under mild, neutral conditions, affording the corresponding anti--hydroxy--amino esters predominantly with excellent enantioselectivities.

Evaluation of the Relationship Between the Catalyst Structure and Regio- as well as Stereoselectivity in the Chiral Ammonium Bifluoride-Catalyzed Asymmetric Addition of Silyl Nitronates to α,β-Unsaturated Aldehydes. Reviewed

Ooi, Takashi; Morimoto, Kumiko; Doda, Kanae; Maruoka, Keiji

Chem. Lett. Vol. 33 page： 824-825 2004

Catalytic Asymmetric Synthesis of a Nitrogen Analogue of Dialkyl Tartrate by Direct Mannich Reaction under Phase-Transfer Conditions. Reviewed

Ooi, Takashi; Kameda, Minoru; Fujii, Junichi; Maruoka, Keiji

Org. Lett. Vol. 6 page： 2397-2399 2004

Language：English Publishing type：Research paper (scientific journal)

Phase-transfer-catalyzed direct Mannich reaction of glycinate Schiff base 3 with -imino ester 4 has been accomplished with high enantioselectivity by the utilization of N-spiro C2-symmetric chiral quaternary ammonium bromide 2 as a catalyst. This methodology enables the catalytic asymmetric synthesis of differentially protected 3-aminoaspartate, a nitrogen analogue of dialkyl tartrate. The product (syn-5) was converted into a precursor (6) of streptolidine lactam.

Highly Enantioselective Alkylation of Glycine Methyl and Ethyl Ester Derivatives under Phase-Transfer Conditions: its Synthetic Advantage. Reviewed

Ooi, Takashi; Uematsu, Yukitaka; Maruoka, Keiji

Tetrahedron Lett. Vol. 45 page： 1675-1678 2004

Language：English Publishing type：Research paper (scientific journal)

Phase-transfer alkylation of the benzophenone Schiff base of glycine methyl or ethyl ester (2) was found to be catalyzed by 3,4,5-F3-C6H2-NAS-Br [(S,S)-1] with high efficiency and excellent enantioselectivity. This procedure allows facile derivatization of the resulting alkylation products to other synthetically useful chiral building blocks.

Design of New Chiral Phase-Transfer Catalysts with Dual Functions for Highly Enantioselective Epoxidation of α,β-Unsaturated Ketones. Reviewed

Ooi, Takashi; Ohara, Daisuke; Tamura, Masazumi; Maruoka, Keiji

J. Am. Chem. Soc. Vol. 126 page： 6844-6845 2004

Language：English Publishing type：Research paper (scientific journal)

A new chiral ammonium bromide possessing diarylmethanol functionality as a substrate recognition site has been designed as a promising, dual-functioning catalyst for the highly enantioselective epoxidation of alpha,beta-unsaturated ketones under mild phase-transfer conditions. A variety of alpha,beta-unsaturated ketones can be epoxidized with rigorous stereochemical control, clearly demonstrating the effectiveness and utility of the present system. Further, a successful single-crystal X-ray diffraction analysis of the catalyst uncovered its distinctive three-dimensional molecular architecture and provided useful information for postulating the transition state.

Efficient Asymmetric Catalysis of Chiral Organoaluminum Complex for Enantioselective Ene Reactions of Aldehydes. Reviewed

Ooi, Takashi; Ohmatsu, Kohsuke; Uraguchi, Daisuke; Maruoka, Keiji

Tetrahedron Lett. Vol. 45 page： 4481-4484 2004

Language：English Publishing type：Research paper (scientific journal)

Chiral organoaluminum complex 1 efficiently catalyzed the asymmetric hetero-ene reaction of commercially available 2-methoxypropene (2) with aldehydes under mild conditions to give the corresponding β-hydroxymethyl ketones 3 in good to excellent chemical yields with high enantiomeric excesses. The asymmetric catalysis of 1 was further applied to the carbonyl addition of methallylsilanes, where exclusive formation of the optically active allylic silanes 5 was achieved.

Development of Highly Diastereo- and Enantioselective Direct Asymmetric Aldol Reaction of a Glycinate Schiff Base with Aldehydes Catalyzed by Chiral Quaternary Ammonium Salts. Reviewed

Ooi, Takashi; Kameda, Minoru; Taniguchi, Mika; Maruoka, Keiji

J. Am. Chem. Soc. Vol. 126 page： 9685-9694 2004

Language：English Publishing type：Research paper (scientific journal)

A highly efficient direct asymmetric aldol reaction of a glycinate Schiff base with aldehydes has been achieved under mild organic/aqueous biphasic conditions with excellent stereochemical control, using chiral quaternary ammonium salt 1b as a phase-transfer catalyst. The initially developed reaction conditions, using 2 equiv of aqueous base (1% NaOH (aq)), exhibited inexplicably limited general applicability in terms of aldehyde acceptors. The mechanistic investigation revealed the intervention of an unfavorable yet inevitable retro aldol process involving the chiral catalyst. On the basis of this information, a reliable procedure has been established by use of a catalytic amount of 1% NaOH (aq) and ammonium chloride, which tolerates a wide range of aldehydes to afford the corresponding anti--hydroxy--amino esters almost exclusively in an essentially optically pure form.

Highly Enantioselective Conjugate Addition of Nitroalkanes to Alkylidenemalonates Using Efficient Phase-Transfer Catalysis of N-Spiro Chiral Ammonium Bromides. Reviewed

Ooi, Takashi; Fujioka, Shingo; Maruoka, Keiji

J. Am. Chem. Soc. Vol. 126 page： 11790-11791 2004

Language：English Publishing type：Research paper (scientific journal)

Highly enantioselective conjugate addition of nitroalkanes to alkylidenemalonates has been accomplished for the first time by the utilization of efficient phase-transfer catalysis of N-spiro C2-symmetric chiral quaternary ammonium bromide 1. For instance, simple mixing of nitropropane (2, R1 = Et), diisopropyl benzylidienemalonate (3, R2 = Ph), Cs2CO3 (1 equiv), and (S,S)-1 (1 mol %) in toluene at 0 C for 2.5 h gave rise to the desired conjugate addition product 4 (R1 = Et, R2 = Ph) quantitatively (anti/syn = 86:14) with 97% ee (anti isomer). The applicability of this procedure has been demonstrated with other representative alkylidenemalonates and nitroalkanes. Since 4 can be readily transformed into the corresponding -amino acid hydrochloride 5 without loss of diastereo- and enantioselectivity, the present method provides a new and practical access to various optically active -amino acid derivatives.

Fluorotetraphenylbismuth: A New Reagent for Efficient Regioselective α-Phenylation of Carbonyl Compounds. Reviewed

Ooi, Takashi; Goto, Ryoji; Maruoka, Keiji

J. Am. Chem. Soc. Vol. 125 page： 10494-10495 2003

Language：English Publishing type：Research paper (scientific journal)

Synthesis and X-ray crystallographic characterization of fluorotetraphenylbismuth (1) has been achieved for the first time, revealing that the bismuth center of 1 adopts a distorted trigonal bipyramidal geometry with three ipso carbons at the equatorial sites and one ipso carbon and fluorine atom at the apical sites. Contrary to the previous common understanding of this type of organobismuth(V) compound, 1 was found to be thermally stable, maintaining its amphiphilic property. Hence, 1 can be used as an off-the-shelf reagent in organic synthesis, and its utility has been clearly demonstrated in applications to the efficient -phenylation of ketones and esters. For instance, simple mixing of 1 and 1-trimethylsiloxy-3,4-dihydronaphthalene in THF at -40 C and stirring at room temperature for 10 min gave rise to 2-phenyl-1-tetralone almost quantitatively without formation of the polyphenylated products. In addition to the generality of this method, applicability of our approach to the selective -alkenylation of carbonyl compounds was also demonstrated by the use of fluoro(2-phenylethenyl)tris(p-tolyl)bismuth (2) as a representative reagent. These results imply the vast potential of organobismuth(V) compounds of type 1 and 2 as useful precursors of a wide variety of pentavalent organobismuth compounds based on the utilization of the eminent fluorine-silicon interaction or the inherent basicity of the fluorine atom.

Designer Chiral Quaternary Ammonium Bifluorides as an Efficient Catalyst for Asymmetric Nitroaldol Reaction of Silyl Nitronates with Aromatic Aldehydes. Reviewed

Ooi, Takashi; Doda, Kanae; Maruoka, Keiji

J. Am. Chem. Soc. Vol. 125 page： 2054-2055 2003

Language：English Publishing type：Research paper (scientific journal)

Designer chiral quaternary ammonium bifluoride 1 has been prepared, and both its catalytic and its chiral efficiency have been clearly demonstrated by achieving the first catalytic asymmetric nitroaldol reaction of silyl nitronate with aldehydes. For instance, the reaction of trimethylsilyl nitronate 2 (R1 = Me) with benzaldehyde (R2 = Ph) in THF in the presence of (S,S)-1 (2 mol %) proceeded smoothly at -78 C, giving the corresponding nitroaldol adduct 3 (R1 = Me, R2 = Ph) in 92% isolated yield (anti/syn = 92:8) with 95% ee (anti isomer). The method was found to be successfully applicable to other aromatic aldehydes and silyl nitronates, and a high level of anti selectivity and enantiomeric excess was constantly observed. This finding should lead to the further development of fluoride ion-catalyzed asymmetric carbon-carbon bond-forming reactions.

Asymmetric Skeletal Rearrangement of Symmetrically α,α-Disubstituted α-Amino Aldehydes: A New Entry to Optically Active α-Hydroxy Ketones. Reviewed

Ooi, Takashi; Saito, Akira; Maruoka, Keiji

J. Am. Chem. Soc. Vol. 125 page： 3220-3221 2003

Language：English Publishing type：Research paper (scientific journal)

A unique asymmetric skeletal rearrangement of symmetrically ,-disubstituted -amino aldehydes has been accomplished for the first time using a chiral organoaluminum Lewis acid 1. For instance, treatment of (S)-2,2'-bis(trifluoromethanesulfonylamino)-1,1'-binaphthyl with Me3Al (1.0 equiv) in toluene at room temperature for 15 min and at 110 C for an additional 15 min produced (S)-1, and a subsequent reaction with -amino aldehyde 2a (R = CH2Ph) at -78 C for 4 h and at -40 C for 12 h resulted in the smooth rearrangement to the zwitterionic iminium intermediate A, which furnished the -hydroxy ketone 3a (R = CH2Ph) in 93% isolated yield with 95% ee (S) after acidic hydrolysis. This result, together with other representative examples, clearly demonstrates the effectiveness of the present method for the hitherto difficult asymmetric synthesis of acyloins. Furthermore, we found that the treatment of the in situ generated A with DIBAH afforded the corresponding anti amino alcohol exclusively without loss of enantiomeric excess. Our approach casts light on the previously unexplored yet potential utility of -amino aldehydes as synthetic building blocks and also provides a new entry to optically active -hydroxy ketones and 1,2-amino alcohols.

Design of N-Spiro C2-Symmetric Chiral Quaternary Ammonium Bromides as Novel Chiral Phase-Transfer Catalysts: Synthesis and Application to Practical Asymmetric Synthesis of α-Amino Acids. Reviewed

Ooi, Takashi; Kameda, Minoru; Maruoka, Keiji

J. Am. Chem. Soc. Vol. 125 page： 5139-5151 2003

Language：English Publishing type：Research paper (scientific journal)

A series of C2-symmetric chiral quaternary ammonium bromides 10 and 11 have been designed as a new, purely synthetic chiral phase-transfer catalyst, and readily prepared from commercially available optically pure 1,1'-bi-2-naphthol as a basic chiral unit. The details of the synthetic procedures of each requisite chiral binaphthyl subunit have been disclosed, and the structures of the assembled N-spiro chiral quaternary ammonium bromides 11a and 11f were unequivocally determined by single-crystal X-ray diffraction analysis. The reactivity and selectivity of these chiral ammonium bromides as chiral phase-transfer catalysts have been evaluated in the asymmetric alkylation of the benzophenone Schiff base of glycine ester 7 under mild liquid-liquid phase-transfer conditions, and the optimization of the reaction variables (solvent, base, and temperature) has also been conducted. Further, the scope and limitations of this asymmetric alkylation have been thoroughly investigated with a variety of alkyl halides, in which the advantage of the unique N-spiro structure of 11 and dramatic effect of the steric as well as the electronic properties of the aromatic substituents on the 3,3'-position of one binaphthyl moiety have been particularly emphasized. Finally, the potential synthetic utility of the present method for the practical asymmetric synthesis of structurally diverse natural and unnatural -amino acids has been demonstrated by its successful application to the facile asymmetric syntheses of (S)-N-acetylindoline-2-carboxylate, a key intermediate in the synthesis of the ACE inhibitor, and L-Dopa (L-3,4-dihydroxyphenylalanine) ester and its analogue.

Highly Enantioselective Michael Addition of Silyl Nitronates to α,β-Unsaturated Aldehydes Catalyzed by Designer Chiral Ammonium Bifluorides: Efficient Access to Optically Active γ-Nitro Aldehydes and Their Enol Silyl Ethers. Reviewed

Ooi, Takashi; Doda, Kanae; Maruoka, Keiji

J. Am. Chem. Soc. Vol. 125 page： 9022-9023 2003

Language：English Publishing type：Research paper (scientific journal)

Highly enantioselective Michael addition of silyl nitronates to ,-unsaturated aldehydes has been accomplished by the utilization of designer N-spiro C2-symmetric chiral quaternary ammonium bifluoride 1 as an efficient catalyst, providing direct access to both optically active -nitro aldehydes, a very useful precursor to various complex organic molecules including aminocarbonyls, and their enol silyl ethers, a Mukaiyama donor of potential synthetic utility for further selective transformations. For instance, the reaction of trimethylsilyl nitronate 2 (R1 = Me) with trans-cinnamaldehyde (R2 = Ph, R3 = H) in toluene in the presence of (R,R)-1 (2 mol %) proceeded smoothly at -78 C to give the desired enol silyl ether 3 (R1 = Me, R2 = Ph, R3 = H) in 90% isolated yield (anti/syn = 83:17) with 97% ee (anti isomer), and simple treatment of 3 thus obtained with 1 N HCl in THF at 0 C afforded the corresponding -nitro aldehyde 4 quantitatively without loss of diastereo- and enantioselectivity.

Highly Stereoselective N-Terminal Functionalization of Small Peptides by Chiral Phase-Transfer Catalysis. Reviewed

Ooi, Takashi; Tayama, Eiji; Maruoka, Keiji

Angew. Chem., Int. Ed. Vol. 42 page： 579-582 2003

Enantioselective Amino Acid Synthesis by Chiral Phase-Transfer Catalysis. Reviewed

Maruoka, Keiji; Ooi, Takashi

Chem. Rev. Vol. 103 page： 3013-3028 2003

Enantioselective synthesis of α-amino acids by chiral phase-transfer catalysis. Reviewed

Ooi, Takashi; Maruoka, Keiji

Yuki Gosei Kagaku Kyokaishi Vol. 61 page： 1195 2003

Practical Asymmetric Synthesis of Vicinal Diamines Through the Catalytic Highly Enantioselective Alkylation of Glycine Amide Derivatives. Reviewed

Ooi, Takashi; Sakai, Daiki; Takeuchi, Mifune; Tayama, Eiji; Maruoka, Keiji

Angew. Chem., Int. Ed. Vol. 42 page： 5868-5870 2003

A New N-Spiro C2-Symmetric Chiral Quaternary Ammonium Bromide Consisting of 4,6-Disubstituted Biphenyl Subunit as an Efficient Chiral Phase-Transfer Catalyst. Reviewed

Ooi, Takashi; Kubota, Yasushi; Maruoka, Keiji

Synlett page： 1931-1933 2003

Language：English Publishing type：Research paper (scientific journal)

A new N-spiro chiral quaternary ammonium bromide has been designed and assembled from optically active 4,6-disubstituted biphenyl subunits. Its utility as an efficient chiral phase-transfer catalyst has been clearly demonstrated by application to the highly enantioselective alkylation of tert-butyl glycinate benzophenone Schiff base.

Corrigendum:Highly Enantioselective Construction of Quaternary Stereocenters on β-Keto Esters by Phase-Transfer Catalytic Asymmetric Alkylation and Michael Reaction. Reviewed

Ooi, Takashi; Miki, Takashi; Taniguchi, Mika; Shiraishi, Misato; Takeuchi, Mifune; Maruoka, Keiji

Angew. Chem., Int.l Ed. Vol. 42 page： 3796-3798 2003

A Scalable Synthesis of (R)-3,5-Dihydro-4H-dinaphth[2,1-c:1'2'-e]azepine. Reviewed

Ikunaka, Masaya; Maruoka, Keiji; Okuda, Yoshiaki; Ooi, Takashi

Org. Proc. Res. Dev. Vol. 7 page： 644-648 2003

Language：English Publishing type：Research paper (scientific journal)

Environmentally benign scalable procedures are developed to supply enantiomerically pure (R)-3,5-dihydro-4H-dinaphth[2,1-c:1'2'-e]azepine 1 as its hydrogen oxalate salt in a five-step overall yield of 41%, which consist of the following: (1) bis O-triflation of (R)-1,1'-bi-2-naphthol 8 [(CF3SO2)2O, pyridine, PhMe; quantitative yield]; (2) Kumada's cross-coupling [MeMgI, NiCl2(dppp), tert-BuOMe; 96% yield]; (3) radical bromination [N-bromosuccinimide, 2,2'-azobisisobutyronitrile, cyclohexane; 54% yield]; (4) cyclization [allylamine, Et3N, THF, 86%]; (5) N-deallylation [1,3-dimethylbarbituric acid, Pd(OAc)2, Ph3P, PhMe] followed by crystalline salt formation with oxalic acid (overall 92% yield).

New, Improved Procedure for the Synthesis of Structurally Diverse N-Spiro C2-Symmetric Chiral Quaternary Ammonium Bromides. Reviewed

Ooi, Takashi; Uematsu, Yukitaka; Maruoka, Keiji

J. Org. Chem. Vol. 68 page： 4576-4578 2003

Language：English Publishing type：Research paper (scientific journal)

Selective, direct ortho magnesiation of (S)-2,2'-bis(isopropoxycarbonyl)-1,1'-binaphthyl (6) has been achieved under mild conditions, using magnesium bis(2,2,6,6-tetramethylpiperamide) [Mg(TMP)2]. In combination with the subsequent reaction with the appropriate electrophiles, bromine and iodine, this method constitutes a key step in establishing a new and concise synthetic route to a wide variety of N-spiro C2-symmetric chiral quaternary ammonium bromides of type 1.

Isopropoxyaluminum 1,1'-Biphenyl-2-oxy-2'-perfluorooctanesulfonamide as a Catalyst for Tishchenko Reaction. Reviewed

Ooi, Takashi; Ohmatsu, Kohsuke; Sasaki, Kouji; Miura, Tomoya; Maruoka, Keiji

Tetrahedron Lett. Vol. 44 page： 3191-3193 2003

Language：English Publishing type：Research paper (scientific journal)

Isopropoxyaluminum 1,1′-biphenyl-2-oxy-2′-perfluorooctanesulfonamide (3) has been evaluated as an aluminum-based catalyst for the Tishchenko reaction. Compound 3 was found to exert high catalytic activity in the reaction with aliphatic aldehydes and also enabled smooth dimerization of enolizable aldehydes. This advantage was highlighted by the quantitative formation of ethyl acetate from acetaldehyde by the present system.

Asymmetric Induction in the Neber Rearrangement of Simple Ketoxime Sulfonates under Phase-Transfer Conditions: Experimental Evidence for the Participation of an Anionic Pathway. Reviewed

Ooi, Takashi; Takahashi, Makoto; Doda, Kanae; Maruoka, Keiji

J. Am. Chem. Soc. Vol. 124 page： 7640-7641 2002

Language：English Publishing type：Research paper (scientific journal)

Phase-transfer catalysis has been successfully utilized for the Neber rearrangement of simple ketoxime sulfonates. For instance, treatment of (Z)-1a with p-toluenesulfonyl chloride (1.2 equiv), tetrabutylammonium bromide (5 mol %) and MeOH (10 equiv) in toluene-50% KOH aqueous solution (volume ratio = 3:1) at 0 C for 2 h, and subsequent benzoylation followed by acidic hydrolysis afforded the protected -amino ketone 2a in 80% isolated yield. On the basis of this finding, asymmetric Neber rearrangement with ketoxime (Z)-1a was examined under phase-transfer conditions using structurally rigid, C2-symmetric chiral quaternary ammonium bromide 3 as catalyst. The desired 2a was obtained in 80% yield and 51% ee. This represents the first experimental demonstration of the substantial involvement of anion pathway in the Neber rearrangement of simple ketoxime sulfonates. Importantly, the reaction with (E)-1a under otherwise similar conditions afforded racemic 2a in 61% yield. Moreover, enhanced enantioselectivity (63% ee) was observed in the rearrangement of the oxime sulfonate derived from (Z)-1b, and notably, use of mesitylene in place of toluene further increased the enantioselectivity to 70% ee. Our approach provides not only a new mechanistic insight but also an opportunity for extending the full synthetic utility of this classical yet useful rearrangement.

Conformationally Flexible, Chiral Quaternary Ammonium Bromides for Asymmetric Phase-Transfer Catalysis. Reviewed

Ooi, Takashi; Uematsu, Yukitaka; Kameda, Minoru; Maruoka, Keiji

Angew. Chem., Int. Ed. Vol. 41 page： 1551-1554 2002

Practical Approach to the Meerwein-Ponndorf-Verley Reduction of Carbonyl Substrates with New Aluminum Catalysts. Reviewed

Ooi, Takashi; Ichikawa, Hayato; Maruoka, Keiji

Angew. Chem., Int. Ed. Vol. 40 page： 3610-3612 2001

"Amphiphilic" Cleavage of γ-Stannyl Ketones with ATPH/RLi: Application to Enone Fragmentation by the Conjugate Addition-Cleavage Sequence. Reviewed

Kondo, Yuichiro; Kon-i, Kana; Iwasaki, Atsuko; Ooi, Takashi; Maruoka, Keiji

Angew. Chem., Int. Ed. Vol. 39 page： 414-416 2000

「光学活性相間移動触媒が拓く有機合成−二相系での実用的不斉合成プロセス」 Invited

亀田　稔, 大井　貴史, 丸岡　啓二

化学 Vol. 55 page： 70-71 2000

Chemistry of chelate-type hypervalent boron and aluminum. Utilization for selective organic synthesis. Reviewed

Uraguchi, Daisuke; Ooi, Takashi; Maruoka, Keiji

Yuki Gosei Kagaku Kyokaishi Vol. 58 page： 14-22 2000

Practical Catalytic Enantioselective Synthesis of α,α-Dialkyl-α-amino Acids by Chiral Phase-Transfer Catalysis. Reviewed

Ooi, Takashi; Takeuchi, Mifune; Kameda, Minoru; Maruoka, Keiji

J. Am. Chem. Soc. Vol. 122 page： 5228-5229 2000

The Synthetic Utility of the Hypercoordination of Boron and Aluminum. Invited Reviewed

Maruoka, Keiji; Ooi, Takashi.

Chem. Eur. J. Vol. 5 page： 829-833 1999

「ルイス酸・塩基を分子内にもつアルミニウム触媒−高度に制御された反応場をもつ不斉触媒の開発」 Invited

市川　隼人, 大井　貴史

化学 Vol. 54 page： 65-66 1999

Pentacoordinate Organoaluminum Chemistry: Catalytic Efficiency of Me3Al in the Epoxide Cleavage with Alkynyllithiums. Reviewed

Ooi, Takashi; Kagoshima, Naoko; Ichikawa, Hayato; Maruoka, Keiji

J. Am. Chem. Soc. Vol. 121 page： 3328-3333 1999

Molecular Design of a C2-Symmetric Chiral Phase-Transfer Catalyst for Practical Asymmetric Synthesis of α-Amino Acids. Reviewed

Ooi, Takashi; Kameda, Minoru; Maruoka, Keiji

J. Am. Chem. Soc. Vol. 121 page： 6519-6520 1999

High activation of carbonyl groups with bidentate Lewis acid catalysts. Reviewed

Ooi, Takashi; Asao, Naoki; Maruoka, Keiji

Yuki Gosei Kagaku Kyokaishi Vol. 56 page： 377-385 1998

Exceptionally Bulky Lewis Acidic Reagent, MAD. Reviewed

Ooi, Takashi; Maruoka, Keiji

Rev. Heteroatom Chem. Vol. 18 page： 61-85 1998

Synthesis of anticancer taxol using Lewis acid-type artificial enzyme. Invited

Maruoka, Keiji; Asao, Naoki; Ooi, Takashi

Ikagaku Oyo Kenkyu Zaidan Kenkyu Hokoku Vol. 16 page： 228-230 1998

Unprecedented Encapsulation of Carbonyl Guest with Designer Lewis Acid Receptor. Reviewed

Ooi, Takashi; Kondo, Yuichiro; Maruoka, Keiji

Angew. Chem., Int. Ed. Vol. 37 page： 3039-3041 1998

First Meerwein-Ponndorf-Verley Alkynylation: Nonorganometallic Way for Carbonyl Alkylations. Reviewed

Ooi, Takashi; Miura, Tomoya; Maruoka, Keiji

J. Am. Chem. Soc. Vol. 120 page： 10790-10791 1998

Hypercoordination of Boron and Aluminum: Synthetic Utility as Chelating Lewis Acids. Reviewed

Ooi, Takashi; Uraguchi, Daisuke; Kagoshima, Naoko; Maruoka, Keiji

J. Am. Chem. Soc. Vol. 120 page： 5327-5328 1998

Rate acceleration in Nucleophilic Alkylation of Carbonyl Compounds with a New Template Containing Two Metallic Centers. Reviewed

Ooi, Takashi; Takahashi, Makoto; Maruoka, Keiji.

Angew. Chem., Int. Ed. Vol. 37 page： 835-837 1998

「ルイス酸のデザイン-二点配位型システムの構築-」 Invited

大井　貴史

化学と工業 Vol. 50 page： 1496-1499 1997

Highly Efficient, Catalytic Meerwein-Ponndorf-Verley Reduction with a Novel Bidentate Aluminum Catalyst. Reviewed

Ooi, Takashi; Miura, Tomoya; Maruoka, Keiji

Angew. Chem., Int. Ed. Vol. 37 page： 2347-2349 1997

Conjugate Allylation to α,β-Unsaturated Aldehydes with the New Chemzyme p-F-ATPH. Reviewed

Ooi, Takashi; Kondo, Yuichiro; Maruoka, Keiji.

Angew. Chem., Int. Ed. Engl. Vol. 36 page： 1183-1185 1997

Remarkable Template Effect of a Lewis Acidic Receptor in Intramolecular Radical Cyclizations. Reviewed

Ooi, Takashi; Hokke, Yasutoshi; Maruoka, Keiji

Angew. Chem., Int. Ed. Engl. Vol. 36 page： 1181-1183 1997

Fluorine-Assisted Selective Alkylation to Fluorinated Epoxides and Carbonyl Compounds: Implication of Pentacoordinate Trialkylaluminum Complexes. Reviewed

Ooi, Takashi; Kagoshima, Naoko; Maruoka, Keiji

J. Am. Chem. Soc. Vol. 119 page： 5754-5755 1997

Exceptionally bulky Lewis acidic reagent, MAD. Reviewed

Ooi, Takashi; Maruoka, Keiji

Yuki Gosei Kagaku Kyokaishi Vol. 54 page： 200-211 1996

(2,7-Dimethyl-1,8-biphenylenedioxy)bis(dimethylaluminum) as a Bidentate Lewis Acid: Its Reactivity and Selectivity in Organic Synthesis. Reviewed

Ooi, Takashi; Takahashi, Makoto; Maruoka, Keiji

J. Am. Chem. Soc. Vol. 118 page： 11307-11308 1996

Rearrangement of trans-stilbene oxide to diphenylacetaldehyde with catalytic methylaluminum bis(4-bromo-2,6-di-tert-butylphenoxide) (oxirane, 2,3-diphenyl-, trans- to benzeneacetaldehyde, α-phenyl-). Reviewed

Ooi, Takashi; Maruoka, Keiji; Yamamoto, Hisashi

Organic Syntheses Vol. 72 page： 95-103 1995

「自己複製する人工分子」 Invited

大井　貴史

ファルマシア Vol. 31 page： 1034-1035 1995

Asymmetric Diels-Alder Reaction of Unsymmetrical Maleates. A Chemical Access to Chiral, Unsymmetrical cis-Cyclohexene-1,2-dicarboxylates. Reviewed

Maruoka, Keiji; Akakura, Matsujiro; Saito, Susumu; Ooi, Takashi; Yamamoto, Hisashi

J. Am. Chem. Soc. Vol. 116 page： 6153-6158 1994

「エポキシドの選択的転位を機軸とする不斉アルドール合成」 Invited

大井　貴史, 丸岡　啓二, 山本　尚

化学 Vol. 48 page： 218-219 1993

Unprecedented Stereochemical Control in the Organoaluminum-Promoted Intramolecular Ene Reactions of δ,ε-Unsaturated Aldehydes. Reviewed

Maruoka, Keiji; Ooi, Takashi; Yamamoto, Hisashi

J. Am. Chem. Soc. Vol. 112 page： 9011-9012 1990

Organoaluminum-Promoted Rearrangement of Epoxy Silyl Ethers to β-Siloxy Aldehydes. Reviewed

Maruoka, Keiji; Ooi, Takashi; Yamamoto, Hisashi

J. Am. Chem. Soc. Vol. 111 page： 6431-6432 1989

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