Search Results - "Ohkata, Katsuo"

Asymmetric synthesis of activated cyclopropanes catalyzed by cinchonidine as a chiral Brønsted base by Kojima, Satoshi, Suzuki, Maki, Watanabe, Akito, Ohkata, Katsuo

“…Cinchonidine catalyzed the cyclopropanation reaction between chloromethyl ketones and β-substituted methylidenemalononitriles to give trans-cyclopropanes with…”
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Construction of the Adamantane Core of Plukenetione-Type Polycyclic Polyprenylated Acylphloroglucinols by Takagi, Ryukichi, Inoue, Yuta, Ohkata, Katsuo

“…The construction of a highly functionalized adamantane core of plukenetione-type polycyclic polyprenylated acylphloroglucinols (PPAPs) is described. The method…”
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Rate acceleration of phosphoric acid-catalyzed Diels-Alder reaction by internal hydrogen-bonding of adjacent hydroxy group by Takagi, Ryukichi, Kondo, Asako, Ohkata, Katsuo

“…The Brønsted acid-catalyzed Diels-Alder reaction was examined. Phosphoric acids were effective Brønsted acids for the Diels-Alder reaction of cyclohexadienones…”
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Studies on Ring-Closing Metathesis for the Formation of the 11-Membered Ring System of Daphnezomine C by Tanabe, Kazuhisa, Fujie, Ayako, Ohmori, Naoki, Hiraga, Yoshikazu, Kojima, Satoshi, Ohkata, Katsuo

“…For the purpose of synthesizing daphnezomine C, model systems were examined to see if the ring-closing metathesis (RCM) reaction could be applied to prepare an…”
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Stereoselectivity Control by Oxaspiro Rings during Diels−Alder Cycloadditions to Cross-Conjugated Cyclohexadienones:  The Syn Oxygen Phenomenon by Ohkata, Katsuo, Tamura, Yukiko, Shetuni, Brandon B, Takagi, Ryukichi, Miyanaga, Wataru, Kojima, Satoshi, Paquette, Leo A

“…The diastereofacial selectivity operating in Diels−Alder additions involving spirocyclic cross-conjugated cyclohexadienones with dienes of varying reactivity…”
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Stereochemical investigation on the construction of poly-functionalized bicyclo[3.3.1]nonenones by successive Michael reactions of 2-cyclohexenones by Takagi, Ryukichi, Miwa, Yukiko, Nerio, Takashi, Inoue, Yuta, Matsumura, Shuji, Ohkata, Katsuo

“…A method for the practical construction of poly-functionalized bicyclo[3.3.1]nonenones by successive Michael reactions of cyclohexenones with acrylates using…”
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One-Pot Synthesis of Adamantane Derivatives by Domino Michael Reactions from Ethyl 2,4-Dioxocyclohexanecarboxylate by Takagi, Ryukichi, Miwa, Yukiko, Matsumura, Shuji, Ohkata, Katsuo

“…Adamantane derivatives were constructed by the one-pot reaction of ethyl 2,4-dioxocyclohexanecarboxylate with 2-phenylethyl 2-(acetoxymethyl)acrylate or…”
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Construction of the bicyclo[3.3.1]nonenone core by successive Michael reactions of 2-cyclohexenone derivatives by Takagi, Ryukichi, Nerio, Takashi, Miwa, Yukiko, Matsumura, Shuji, Ohkata, Katsuo

“…[Display omitted] Construction of the bicyclo[3.3.1]nonenone core was achieved by stepwise annulation of 2-cyclohexenone derivatives and acrylates via…”
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Two-parameter Analysis of Solvent Effects on Selectivity in Chemical Reactions: Information of Polarity and Activation Volume at the Transition State in Organic and Enzymatic Reactions by Lin, Chunlei, Hiraga, Yoshikazu, Ohkata, Katsuo

“…The solvent effects on stereoselectivity in the Diels–Alder reaction of cyclopentadiene, the [2 + 2]photodimerization of 2-cyclopentenone, and the enzymatic…”
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Highly Stereoselective 7-Membered Ring Synthesis Based upon the Oxidopyrylium–Alkene [5+2]Cycloaddition Reaction by Ohmori, Naoki, Miyazaki, Toru, Kojima, Satoshi, Ohkata, Katsuo

“…The [5+2]cycloaddition reaction of 2-substituted-3-oxidopyrylium betaine with dialkyl fumarates was found to proceed with stereoselectivity up to 15.5 : 1. The…”
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Influence of solvent viscosity on the rate of hydrolysis of dipeptides by carboxypeptidase Y by Kanosue, Yoshifumi, Kojima, Satoshi, Ohkata, Katsuo

“…The influence of solvent viscosity on the rate of enzymatic hydrolysis of a series of dipeptides (Z‐Phe‐Gly, Z‐Phe‐Sar, Z‐Phe‐Ala, Z‐Phe‐NMeAla, Z‐Phe‐Aib and…”
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Stereoselective cyclopropanation of 3-aryl-2-phosphonoacrylates induced by the (−)-8-phenylmenthyl group as a chiral auxiliary by Takagi, Ryukichi, Nakamura, Minoru, Hashizume, Miki, Kojima, Satoshi, Ohkata, Katsuo

“…The cyclopropanation of (−)-8-phenylmenthyl ( E)-3-aryl-2-phosphonoacrylates with dimethyloxosulfonium methylide and diazomethane afforded the corresponding…”
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The Juliá-Colonna Type Asymmetric Epoxidation Reaction Catalyzed by Soluble Oligo-L-leucines Containing an α-Aminoisobutyric Acid Residue: Importance of Helical Structure of the Catalyst on Asymmetric Induction by Takagi, Ryukichi, Shiraki, Akiko, Manabe, Toshiki, Kojima, Satoshi, Ohkata, Katsuo

“…Length-defined organic solvent soluble oligo-L-leucines containing an Aib residue were prepared by stepwise elongation and fragment condensation methods, and…”
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The Effect of Substituents on the Pyridine Ring in the Diastereoselective Cyclopropa- nation Reaction of Pyridinium Ylides Bear- ing an 8-Phenylmenthyl Ester Group by Kojima, Satoshi, Fujitomo, Kouji, Itoh, Yoshiaki, Hiroike, Kyoko, Murakami, Masaaki, Ohkata, Katsuo

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The Juliá-Colonna Asymmetric Epoxidation Reaction of Chalcone Catalyzed by Length Defined Oligo-L-leucine: Importance of the N-Terminal Functional Group and Helical Structure of the Catalyst in the Asymmetric Induction by Takagi, Ryukichi, Manabe, Toshiki, Shiraki, Akiko, Yoneshige, Arata, Hiraga, Yoshikazu, Kojima, Satoshi, Ohkata, Katsuo

“…Catalysts, oligo-L-leucine, for the Juliá-Colonna asymmetric epoxidation of chalcone with defined degrees of polymerization were prepared by a stepwise…”
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Computational Study on Conformational Features of Protonated 5H,7H-Dibenzo- [b,g][1,5]dithiocin Oxides by ab initio MO Calculations by Ohkata, Katsuo, Okada, Keiji, Tanaka, Masato

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Kinetic Evidence for the Hydrophobic Atmosphere of the Catalytic Cavity in Carboxypeptidase Y Based on a Linear Relationship between Michaelis–Menten Constant Km and Hydrophobicity of the Substrates by Kanosue, Yoshifumi, Hiraga, Yoshikazu, Kojima, Satoshi, Ohkata, Katsuo

“…In the hydrolysis of several dipeptides by carboxypeptidase-Y (CPD-Y), there was found a good linear relationship (r = 0.999) between Michaelis–Menten constant…”
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Hydrophobicity and Structure of 1,2,4-Triazole Derivatives Bearing 1-Carbamoyl and 3-Sulfonyl Groups by Ohkata, Katsuo, Yano, Tomoyuki, Kojima, Satoshi, Hiraga, Yoshikazu, Yoshii, Tomoko, Hori, Masahiro

“…Various 3-sulfonyl-1,2,4-triazole-1-carboxamides (5a–h) were synthesized and their hydrophobicities were evaluated from their retention time in reversed-phase…”
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Stereoselective Formation of trans-2,5-Disubstituted Tetrahydropyrans by Intramolecular Nucleophilic Substitution and a Computational Study at the AM1 Level by Takagi, Ryukichi, Nishitani, Hiroko, Takenami, Sigeharu, Okada, Kazumasa, Kojima, Satoshi, Ohkata, Katsuo

“…The synthesis of 2,5-disubstituted tetrahydropyrans bearing a hydrophobic moiety at the C5 position from (E)- and (Z)-7-hydroxy-6-substituted 2,3-unsaturated…”
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Tandem reactions in 4-siloxy-1-benzopyrylium salts: introduction of substituents and cyclohexene and cyclopentane annulation in chromones by Lee, Yong Gyun, Ishimaru, Kenji, Iwasaki, Hideharu, Ohkata, Katsuo, Akiba, Kinya

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