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Dive into the research topics where Katsuyuki Ogura is active.

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Featured researches published by Katsuyuki Ogura.


Tetrahedron Letters | 1995

Palladium(0)/LiCl promoted cross-coupling reaction of (4-pyridyl)stannanes and aromatic bromides: Easy access to poly(4-pyridyl)-substituted aromatics

Makoto Fujita; Hiroko Oka; Katsuyuki Ogura

Abstract A PdCl 2 (PPh 3 ) 2 /LiCl catalyst effectively promoted the cross-coupling reaction of trimethyl(4-pyridyl)stannane and aromatic polybromides to offer easy access to poly(4-pyridyl)-substituted aromatic compounds.


Tetrahedron | 1997

Enantiomeric recognition of alkyl phenyl sulfoxides by crystalline (R)-phenylglycyl-(R)-phenylglycine

Motohiro Akazome; Makoto Noguchi; Osamu Tanaka; Atsuko Sumikawa; Tohru Uchida; Katsuyuki Ogura

Abstract The inclusion compounds of several alkyl phenyl sulfoxides by (R)-phenylglycyl-(R)-phenylglycine [ (R,R)- 1 ] were prepared by two different methods (sorption and crystallization). Alkyl phenyl sulfoxides entered crystalline (R,R)- 1 with high S-enantioselectivity except for methyl phenyl sulfoxide which was recognized with high and reverse enantioselectivity (R-from in 92% ee). From the X-ray crystallographic study of an inclusion compound of bis[(o-methylsulfinyl)benzyl]ether (3) and (R,R)- 1 , it is deduced that the reversal of enantioselectivity was achieved by the conformational change of phenyl groups on the dipeptide layer.


Tetrahedron Letters | 1998

Novel reaction of allylic alcohols with a hexafluoropropene-diethylamine adduct (PPDA) to form α-fluoro-α-(trifluoromethyl)-γ,δ-unsaturated amides

Ken-ichi Ogu; Motohiro Akazome; Katsuyuki Ogura

Abstract Treatment of allylic alcohols ( 1 ) with a hexafluoropropene-diethylamine adduct (PPDA) gave α-fluoro-α-(trifluoromethyl)-γ,δ-unsaturated amides ( 2 ), which were shown to be important precursors for synthesizing a variety of fluoro(trifluoromethyl)methylene-containing compounds.


Tetrahedron Letters | 1997

Stereoselective formation of α-fluoro-α-trifluoromethyl-γ-lactones starting from γ-hydroxy-α,β-unsaturated sulfones and a hexafluoropropene-diethylamine adduct (PPDA)

Katsuyuki Ogura; Ken-ichi Ogu; Takashi Ayabe; Jun-ichi Sonehara; Motohiro Akazome

Abstract ( E )-3-Hydroxy-1-alkenyl p -tolyl sulfones ( 1 ) reacted with a hexafluoropropene-diethylamine adduct (PPDA) to afford α-fluoro-α-(trifluoromethyl)-β-[( p -tolylsulfonyl)methyl]-γ-lactones ( 2 ). This reaction is so stereoselective that only one diastereomer of 2 is detected in the reaction mixture. A plausible mechanism for this intriguing reaction is discussed.


Tetrahedron | 1997

Highly stereoselective radical addition to 3-hydroxy-1-(methylthio)-1-(p-tolylsulfonyl)-1-alkenes and its application to the preparation of optically active compounds

Akio Kayano; Motohiro Akazome; Makoto Fujita; Katsuyuki Ogura

Abstract Efficient 1,2-asymmetric induction was realized in the addition of a 1-hydroxyalkyl radical (R2C-OH) to 3-hydroxy-1-(methylthio)-1-(p-tolylsulfonyl)-1-alkenes and their acetates (1): Irradiation of 1 and benzophenone in an alcohol (R2CHOH) gave an adduct (2) with a high syn selectivity. Optically active 1 is easily obtainable by means of Lipase PS-catalyzed transesterification and, therefore, the present radical asymmetric induction provides a synthetic route leading to various chiral compounds.


Tetrahedron-asymmetry | 1997

Asymmetric recognition of 1-arylethylamines by (R)-phenylglycyl-(R)-phenylglycine and its mechanism

Motohiro Akazome; Hirozumi Matsuno; Katsuyuki Ogura

Abstract An unprotected dipeptide, ( R )-phenylglycyl-( R )-phenylglycine, which is insoluble in water, was shown to be an excellent resolving reagent for racemic 1-arylethylamines. By simply stirring the mixture of the dipeptide and racemic 1-phenylethylamine in presence of water, asymmetric recognition occurred to give a salt of ( S )-1-phenylethylamine (95% ee) and the dipeptide. X-Ray crystallographic study of the salt elucidated the crystal structure of the diastereomeric salt, where hydrogen bonding and hydrophobic interaction between the dipeptide and amines play important roles in the construction of layers.


Journal of the American Chemical Society | 1995

Interpenetrating Molecular Ladders and Bricks

Makoto Fujita; Yoon Jung Kwon; Osamu Sasaki; Kentaro Yamaguchi; Katsuyuki Ogura


Journal of the American Chemical Society | 1996

CATENANE FORMATION FROM TWO MOLECULAR RINGS THROUGH VERY RAPID SLIPPAGE : A MOBIUS STRIP MECHANISM

Makoto Fujita; Fumiaki Ibukuro; Hiroko Seki; Osamu Kamo; and Mamoru Imanari; Katsuyuki Ogura


Bulletin of the Chemical Society of Japan | 1996

Facile Optical Resolution of a Dibenzopyrazinoazepine Derivative and the Nature of Molecular Recognition of Amines by Chiral 2,3-Di-O-(arylcarbonyl)tartaric Acids

Hiroshi Tomori; Hisayoshi Yoshihara; Katsuyuki Ogura


Bulletin of the Chemical Society of Japan | 1996

Lipase-Catalyzed Practical Synthesis of (R)-1-Benzyl-3-hydroxy-2,5-pyrrolidinedione and Its Related Compounds

Hiroshi Tomori; Kuniko Shibutani; Katsuyuki Ogura

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