研究者詳細 - 大井　貴史

論文 - 大井　貴史

分割表示 203 件中 101 - 120 件目／全件表示 >>

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

Uraguchi, Daisuke; Ooi, Takashi

有機合成化学協会誌 68 巻頁： 1185-1194 2010年11月

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

Uraguchi, Daisuke; Koshimoto, Kyohei; Ooi, Takashi

Chem. Commun. 46 巻頁： 300-302 2010年

Development of D2-Symmetric Chiral Tetraaminophosphonium Salts as a Catalyst for Asymmetric Phase-Transfer Reactions 招待有り査読有り

Uraguchi, Daisuke; Ooi, Takashi

39 巻頁： 42-48 2010年

Development of Ion-Pair Cooperative Asymmetric Catalyses of Chiral Phosphonium Salts Possessing an Organic Anion 招待有り査読有り

Ueki, Yusuke; Uraguchi, Daisuke; Ooi, Takashi

52 巻頁： 509-514 2010年

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

Uraguchi, Daisuke; Kinoshita, Natsuko; Ooi, Takashi

J. Am. Chem. Soc. 132 巻頁： 12240-12242 2010年

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

Uraguchi, Daisuke; Nakamura, Shinji; Ooi, Takashi

Angew. Chem. Int. Ed. 49 巻頁： 7562–7565 2010年

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

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 査読有り

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

Angew. Chem. Int. Ed. 49 巻頁： 5567-5569 2010年

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

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 招待有り

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

Chemical Science 1 巻頁： 488-490 2010年

Performance of C1-symmetric chiral ammonium betaines as a catalyst for the enantioselective Mannich-type reaction of α-nitrocarboxylates 招待有り査読有り

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

Tetrahedron: Asymmetry 21 巻頁： 1189-1190 2010年

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

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 査読有り

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

Chem. Asian J. 5 巻頁： 562-570 2010年

記述言語：英語掲載種別：研究論文（学術雑誌）

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 査読有り

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

Tetrahedron: Asymmetry 21 巻頁： 1189-1190 2010年

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

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

Chem. Lett. 38 巻頁： 1052-1053 2009年11月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

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 査読有り

Uraguchi, Daisuke; Ueki, Yusuke; Ooi, Takashi

Science 326 巻頁： 120-123 2009年10月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

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 査読有り

Daisuke Uraguchi, Daisuke Nakashima and Takashi Ooi

J. Am. Chem. Soc. 131 巻 ( 21 ) 頁： 7242-7243 2009年5月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

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 招待有り査読有り

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

Synlett ( 4 ) 頁： 658-660 2009年2月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

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.

Phase-Transfer-Catalyzed Enantioselective Alkylation of α-Benzoyloxy-β-Keto Ester 招待有り査読有り

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

Synlett ( 4 ) 頁： 661-663 2009年2月

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

Uraguchi, Daisuke; Ito, Takaki; Ooi, Takashi

J. Am. Chem. Soc. 131 巻 ( 11 ) 頁： 3836–3837 2009年2月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

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.

*Site-directed Asymmetric Quaternization of a Peptide Backbone at C-Terminal Azlactone 査読有り

Uraguchi, Daisuke; Asai, Yoshihiro; Ooi, Takashi

Angew. Chem. Int. Ed. 48 巻 ( 3 ) 頁： 733-737 2009年1月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

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 査読有り

Kohsuke Ohmatsu, Takayuki Tanaka, Takashi Ooi, Keiji Maruoka

Tetrahedron 65 巻頁： 7516-7522 2009年

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

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 査読有り

Uraguchi, Daisuke; Koshimoto, Kyohei; Ooi, Takashi

J. Am. Chem. Soc. 130 巻 ( 33 ) 頁： 10878-10879 2008年7月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

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.

　前のページ - 次のページ　

<大井 貴史>

論文 - 大井 貴史

<大井　貴史>

論文 - 大井　貴史