scholarly journals Enantioselective Benzylation and Allylation of α-Trifluoromethoxy Indanones under Phase-Transfer Catalysis

Molecules ◽  
2019 ◽  
Vol 24 (15) ◽  
pp. 2774 ◽  
Author(s):  
Yumeng Liang ◽  
Mayaka Maeno ◽  
Zhengyu Zhao ◽  
Norio Shibata
Keyword(s):  
Phase Transfer Catalysis ◽  
Phase Transfer ◽  
Cinchona Alkaloid ◽  
Chiral Phase ◽  
Phase Transfer Catalysts ◽  
Excellent Yield ◽  
Chiral Phase Transfer Catalysts ◽  
Moderate Yield

The organo-catalyzed enantioselective benzylation reaction of α-trifluoromethoxy indanones afforded α-benzyl-α-trifluoromethoxy indanones with a tetrasubstituted stereogenic carbon center in excellent yield with moderate enantioselectivity (up to 57% ee). Cinchona alkaloid-based chiral phase transfer catalysts were found to be effective for this transformation, and both enantiomers of α-benzyl-α-trifluoromethoxy indanones were accessed, depended on the use of cinchonidine and cinchonine-derived catalyst. The method was extended to the enantioselective allylation reaction of α-trifluoromethoxy indanones to give the allylation products in moderate yield with good enantioselectivity (up to 76% ee).

scholarly journals Enantioselective Benzylation and Allylation of α-Trifluoromethoxy Indanones under Phase-Transfer Catalysis

2019 ◽  
Author(s):  
Yumeng Liang ◽  
Mayaka Maeno ◽  
Zhengyu Zhao ◽  
Norio Shibata
Keyword(s):  
Phase Transfer Catalysis ◽  
Phase Transfer ◽  
Cinchona Alkaloid ◽  
Chiral Phase ◽  
Phase Transfer Catalysts ◽  
Excellent Yield ◽  
Chiral Phase Transfer Catalysts ◽  
Moderate Yield

The organo-catalyzed enantioselective benzylation reaction of α-trifluoromethoxy indanones afforded α-benzyl-α-trifluoromethoxy indanones with a tetrasubstituted stereogenic carbon center in excellent yield with moderate enantioselectivity (up to 57% ee). Cinchona alkaloid-based chiral phase transfer catalysts were found to be effective for this transformation, and both enantiomers of α-benzyl-α-trifluoromethoxy indanones were accessed, depended on the use of cinchonidine and cinchonine-derived catalyst. The method was extended to the enantioselective allylation reaction of α-trifluoromethoxy indanones to give the allylation products in moderate yield with good enantioselectivity (up to 76% ee).

scholarly journals Chiral Phase-Transfer Catalysts with Hydrogen Bond: A Powerful Tool in the Asymmetric Synthesis

Catalysts ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 244 ◽  
Author(s):  
Hongyu Wang
Keyword(s):  
Organic Synthesis ◽  
Phase Transfer Catalysis ◽  
Phase Transfer ◽  
Chiral Phase ◽  
Design Synthesis ◽  
Phase Transfer Catalysts ◽  
The Past ◽  
Hydrogen Bonding Interactions ◽  
Chiral Phase Transfer Catalysts ◽  
Made In

Asymmetric phase-transfer catalysis has been widely applied into organic synthesis for efficiently creating chiral functional molecules. In the past decades, chiral phase-transfer catalysts with proton donating groups are emerging as an extremely significant strategy in the design of novel catalysts, and a large number of enantioselective reactions have been developed. In particular, the proton donating groups including phenol, amide, and (thio)-urea exhibited unique properties for cooperating with the phase-transfer catalysts, and great advances on this field have been made in the past few years. This review summarizes the seminal works on the design, synthesis, and applications of chiral phase-transfer catalysts with strong hydrogen bonding interactions.

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.

Diastereo- and enantioselective nitro-Mannich reaction of isatin-derived N-Boc ketimines catalyzed by chiral phase-transfer catalysts

2018 ◽  
Vol 42 (3) ◽  
pp. 1608-1611 ◽  
Author(s):  
Yuxin Liu ◽  
Jingdong Wang ◽  
Zhonglin Wei ◽  
Jungang Cao ◽  
Dapeng Liang ◽  
...  
Keyword(s):  
Mannich Reaction ◽  
Phase Transfer ◽  
Cinchona Alkaloid ◽  
Chiral Phase ◽  
Phase Transfer Catalysts ◽  
Chiral Phase Transfer Catalysts

A series of 3-substituted 3-amino-oxindoles were constructed in excellent yields (96–99%) with high enantioselectivities (up to 95% ee) and diastereoselectivities (up to 95 : 5 dr) catalyzed by Cinchona alkaloid-derived phase-transfer catalysts.

Asymmetric synthesis of β-amino ketones by using cinchona alkaloid-based chiral phase transfer catalysts

2018 ◽  
Vol 16 (45) ◽  
pp. 8704-8709 ◽  
Author(s):  
Weihua Li ◽  
Yifeng Wang ◽  
Danqian Xu
Keyword(s):  
Asymmetric Synthesis ◽  
Nucleophilic Addition ◽  
Phase Transfer ◽  
Cinchona Alkaloid ◽  
Reaction Products ◽  
Chiral Phase ◽  
Phase Transfer Catalysts ◽  
Chiral Phase Transfer Catalysts ◽  
The Mannich Reaction ◽  
High Yields

A highly enantioselective nucleophilic addition of ketones to versatile imines catalyzed by chiral PTC has been developed, and the process affords the Mannich reaction products with tertiary stereocenters in good to high yields and excellent enantioselectivities. This protocol is effective for gram scale reaction.

Asymmetric synthesis of 3-phenyl-2,3-dihydro-1H-pyrrolo[3,2-b]pyridine-3-carbonitriles catalysed by phase transfer catalyst derived from tert-leucine.

Synlett ◽  
2021 ◽  
Author(s):  
Zhiqi Zhao ◽  
Jingdong Wang ◽  
lin zhong wei ◽  
gang jun cao ◽  
peng da liang ◽  
...  
Keyword(s):  
Asymmetric Synthesis ◽  
Phase Transfer ◽  
Phase Transfer Catalyst ◽  
Chiral Phase ◽  
Phase Transfer Catalysts ◽  
Excellent Yield ◽  
Chiral Phase Transfer Catalysts

Chiral phase transfer catalysts derived from tert-leucine were synthesized and used in the aymmetric synthesis of 4-azaindoline derivatives. By this method, both enantiomers of corresponding products were obtained in excellent yield (up to 99%) with high enantioselectivity (up to 91% ee) and diastereoselectivity (up to >99: 1 dr).

9-Amino-(9-deoxy)cinchona alkaloid-derived new chiral phase-transfer catalysts

2014 ◽  
Vol 12 (41) ◽  
pp. 8336-8345 ◽  
Author(s):  
Wenwen Peng ◽  
Jingwei Wan ◽  
Bing Xie ◽  
Xuebing Ma
Keyword(s):  
Schiff Base ◽  
Phase Transfer ◽  
Cinchona Alkaloid ◽  
Chiral Phase ◽  
Phase Transfer Catalysts ◽  
Chiral Phase Transfer Catalysts ◽  
High Yields

9-Amino-(9-deoxy)cinchona alkaloid-derived chiral phase-transfer catalysts achieved high yields (92–99%) and excellent enantioselectivities (87–96% ee) in the enantioselective α-alkylation of glycine Schiff base.

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