Asymmetric epoxidation of α,β-unsaturated ketones under phase-transfer catalyzed conditions

1998 ◽  
Vol 39 (41) ◽  
pp. 7563-7566 ◽  
Author(s):  
Shigeru Arai ◽  
Hiroki Tsuge ◽  
Takayuki Shioiri
Keyword(s):  
Phase Transfer ◽  
Asymmetric Epoxidation ◽  
Unsaturated Ketones

scholarly journals A Remarkably Efficient Phase-Transfer Catalyzed Amination of α-Bromo-α, β-Unsaturated Ketones in Water

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Alemayehu Mekonnen ◽  
Alemu Tesfaye
Keyword(s):  
Quaternary Ammonium ◽  
Phase Transfer ◽  
Conjugate Addition ◽  
Quaternary Ammonium Salts ◽  
Cinchona Alkaloids ◽  
Ammonium Salts ◽  
Alkylation Reaction ◽  
Pt Catalysts ◽  
Unsaturated Ketones ◽  
Catalytic Performances

Tandem conjugate addition–alkylation reaction of various amines with α-bromo-α, β-unsaturated ketones resulted in near-quantitative conversions into the corresponding aziridines when the reaction was carried out in the presence of 10 mol% of phase-transfer, PT catalysts in water. Some chiral quaternary ammonium salts derived from Cinchona alkaloids were investigated as water-stable PT catalysts. The scope and limitations of the reaction have also been investigated. The catalytic performances were significantly improved in comparison with the corresponding ordinary quaternary ammonium salt catalysts, and excellent yields (81%–96%) were obtained. Although an increase in the rate of aziridination has been accomplished, no stereoselectivity was observed. The positive values of the protocol have been confirmed.

Phase-transfer catalyzed asymmetric epoxidation of chalcones using chiral crown ethers derived from d-glucose, d-galactose, and d-mannitol

2004 ◽  
Vol 15 (10) ◽  
pp. 1589-1595 ◽  
Author(s):  
Tibor Bakó ◽  
Péter Bakó ◽  
György Keglevich ◽  
Petra Bombicz ◽  
Miklós Kubinyi ◽  
...  
Keyword(s):  
Crown Ethers ◽  
Phase Transfer ◽  
Asymmetric Epoxidation ◽  
Chiral Crown Ethers

scholarly journals Asymmetric epoxidation of α,β-unsaturated ketones catalyzed by chiral ytterbium complexes

2001 ◽  
Vol 42 (39) ◽  
pp. 6919-6921 ◽  
Author(s):  
Ruifang Chen ◽  
Changtao Qian ◽  
Johannes G. de Vries
Keyword(s):  
Asymmetric Epoxidation ◽  
Unsaturated Ketones ◽  
Ytterbium Complexes
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