scholarly journals Studies on the Stereochemistry in the Alkylation of Enolate Ion of Cyclic β-Keto Ester with Sulfonium Salts Containing Optically Active Alkyl Groups

1987 ◽  
Vol 16 (2) ◽  
pp. 327-328 ◽  
Author(s):  
Michio Kobayashi ◽  
Kazuyuki Umemura ◽  
Haruo Matsuyama
Keyword(s):  
Optically Active ◽  
Sulfonium Salts ◽  
Keto Ester ◽  
Alkyl Groups

Asymmetric alkylation of .beta.-keto esters with optically active sulfonium salts

1989 ◽  
Vol 54 (10) ◽  
pp. 2374-2383 ◽  
Author(s):  
Kazuyuki Umemura ◽  
Haruo Matsuyama ◽  
Nobuko Watanabe ◽  
Michio Kobayashi ◽  
Nobumasa Kamigata
Keyword(s):  
Optically Active ◽  
Sulfonium Salts ◽  
Asymmetric Alkylation ◽  
Keto Esters

Organocatalyzed Friedel–Craft-type reaction of 2-naphthol with β,γ-unsaturated α-keto ester to form novel optically active naphthopyran derivatives

2008 ◽  
Vol 19 (23) ◽  
pp. 2699-2704 ◽  
Author(s):  
Xiao-Sheng Wang ◽  
Chang-Wu Zheng ◽  
Sheng-Li Zhao ◽  
Zhuo Chai ◽  
Gang Zhao ◽  
...  
Keyword(s):  
Optically Active ◽  
Keto Ester ◽  
Type Reaction

ChemInform Abstract: Organocatalyzed Friedel-Crafts-Type Reaction of 2-Naphthol with β,γ-Unsaturated α-Keto Ester to Form Novel Optically Active Naphthopyran Derivatives (III).

ChemInform ◽  
2009 ◽  
Vol 40 (24) ◽  
Author(s):  
Xiao-Sheng Wang ◽  
Chang-Wu Zheng ◽  
Sheng-Li Zhao ◽  
Zhuo Chai ◽  
Gang Zhao ◽  
...  
Keyword(s):  
Optically Active ◽  
Keto Ester ◽  
Type Reaction

ChemInform Abstract: Asymmetric Alkylation of β-Keto Esters with Optically Active Sulfonium Salts.

ChemInform ◽  
1989 ◽  
Vol 20 (44) ◽  
Author(s):  
K. UMEMURA ◽  
H. MATSUYAMA ◽  
N. WATANABE ◽  
M. KOBAYASHI ◽  
N. KAMIGATA
Keyword(s):  
Optically Active ◽  
Sulfonium Salts ◽  
Asymmetric Alkylation ◽  
Keto Esters

Dynamisches Verhalten, Konformation und Bindungsverhältnisse von Enaminosulfoniumsalzen / Dynamic Behaviour, Conformation and Bonding of Enaminosulfonium Salts

1980 ◽  
Vol 35 (11) ◽  
pp. 1406-1414
Author(s):  
Joachim Firl ◽  
Heinz Braun ◽  
Anton Amann ◽  
Robert Barnert
Keyword(s):  
Dihedral Angle ◽  
Dynamic Behaviour ◽  
Chemical Shifts ◽  
Single Bond ◽  
Sulfonium Salts ◽  
Rotational Barriers ◽  
Alkyl Groups ◽  
Vinyl Group ◽  
High Degree

AbstractThe rotational barriers about the C-N single bond of the enaminosulfonium salts 1-6 are measured. Their magnitudes are related to the π-donor strength of the NR2 group. For the unsymmetrically substituted compounds 7-12 the rotational equilibria are determined. In the case of the monoalkyl compounds 7-10 the more crowded s-cis-rotamers turn out to be the more stable conformations. Furthermore, the 13C chemical shifts of the sulfonium salts 1-16 are reported. The shift differences δ(s-cis-s-trans) for the α-carbons of the N-alkyl groups seem to depend on the dihedral angle between the vinyl group and the C-H(α-c) bonds. Moreover, the spectra reveal that enaminosulfonium salts posses a high degree of ylide character.

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