Ultrasonic assisted dimeric cinchona based chiral phase transfer catalysts for highly enanatioselective synthesis of epoxidation of α,β-unsaturated ketones

RSC Advances ◽  
2014 ◽  
Vol 4 (104) ◽  
pp. 60293-60299 ◽  
Author(s):  
Jayaraman Sivamani ◽  
Veeramanoharan Ashokkumar ◽  
Velu Sadhasivam ◽  
Kumaraguru Duraimurugan ◽  
Ayyanar Siva
Keyword(s):  
Ultrasonic Irradiation ◽  
Phase Transfer ◽  
Cinchona Alkaloids ◽  
Ammonium Bromide ◽  
Chiral Phase ◽  
Unsaturated Ketones ◽  
Phase Transfer Catalysts ◽  
Ultrasonic Assisted ◽  
Chiral Phase Transfer Catalysts ◽  
Enantioselective Epoxidation

New types of bis-quaternary ammonium bromide as chiral multisite phase transfer catalysts derived from cinchona alkaloids have been developed and evaluated for the enantioselective epoxidation of chalcones in the presence of lower concentrations of various oxidants, bases and ultrasonic irradiation conditions.

scholarly journals Review on Asymmetric Transformations with Chiral Phase-Transfer Catalysts

2019 ◽  
pp. 6-12
Author(s):  
Tesfaye Tebeka ◽  
Atitegebe Abera
Keyword(s):  
Unnatural Amino Acids ◽  
Phase Transfer Catalysis ◽  
Phase Transfer ◽  
Biological Activities ◽  
Industrial Applications ◽  
Cinchona Alkaloids ◽  
Chiral Phase ◽  
Asymmetric Transformations ◽  
Phase Transfer Catalysts ◽  
Chiral Phase Transfer Catalysts

This review focuses onasymmetric transformations with Chiral Phase-Transfer Catalysts and its application. Phase-transfer catalysis is practical methodology for organic synthesis. It is possible to achieve highly enantio selective transformations under phase-transfer conditions for a variety of ─C─C─ ─C─O─ and ─C─N─ bond-forming reactions. The asymmetric transformations using modified cinchona alkaloids, chiral spiro ammonium salts and crown ether are among the primary source of effective chiral phase-transfer catalyst, which allows access to enantiomerically pure unnatural amino acids and synthetically useful adducts containing quaternary stereogenic centers. The advantage of this method is its simple experimental procedure, large chiral pool, mild reaction condition, inexpensive, environmentally benign reagent and use of simple and inexpensive reactants. Nowadays, it appears to be the most important synthetic method used in various fields of organic chemistry, and also found widespread industrial applications. This review summarizes the synthesis application, enantio selective transformation of some selected reaction, biological activities and catalytic activities of Phase-transfer catalysis and especial emphasis is given for organo catalysis. In asymmetric organo catalyst, it is possible to obtain chiral organic products in high enantio enriched form by steric hindrance approach method. The advantage of organic molecules as chiral catalysts complements the traditional organo-metallic and biological approaches to asymmetric catalysis.

Highly enantioselective asymmetric Henry reaction catalyzed by novel chiral phase transfer catalysts derived from cinchona alkaloids

2016 ◽  
Vol 14 (42) ◽  
pp. 10101-10109 ◽  
Author(s):  
Ponmuthu Kottala Vijaya ◽  
Sepperumal Murugesan ◽  
Ayyanar Siva
Keyword(s):  
Phase Transfer ◽  
Enantiomeric Excess ◽  
Cinchona Alkaloids ◽  
Henry Reaction ◽  
Reaction Conditions ◽  
Chiral Phase ◽  
Phase Transfer Catalysts ◽  
Wide Range ◽  
Chiral Phase Transfer Catalysts

Newly synthesized CPTCs are applied in the asymmetric Henry reaction to a wide range of aldehydes under mild reaction conditions, and we obtained higher chemical yields and an excellent enantiomeric excess.

Polymeric chiral phase-transfer catalysts derived from cinchona alkaloids for enantioselective synthesis of α-amino acids

Tetrahedron ◽  
2007 ◽  
Vol 63 (33) ◽  
pp. 7906-7915 ◽  
Author(s):  
Jeong-Hee Lee ◽  
Mi-Sook Yoo ◽  
Ji-Hee Jung ◽  
Sang-sup Jew ◽  
Hyeung-geun Park ◽  
...  
Keyword(s):  
Amino Acids ◽  
Phase Transfer ◽  
Cinchona Alkaloids ◽  
Enantioselective Synthesis ◽  
Chiral Phase ◽  
Phase Transfer Catalysts ◽  
Chiral Phase Transfer Catalysts
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