Enantioselective N-Alkylation of Nitroindoles under Phase-Transfer Catalysis

Synthesis ◽  
2019 ◽  
Vol 52 (07) ◽  
pp. 1047-1059 ◽  
Author(s):  
Dmitri Trubitsõn ◽  
Jevgenija Martõnova ◽  
Kristin Erkman ◽  
Andrus Metsala ◽  
Jaan Saame ◽  
...  
Keyword(s):  
Phase Transfer Catalysis ◽  
Michael Reaction ◽  
Phase Transfer ◽  
Spectrophotometric Titration ◽  
Cinchona Alkaloid ◽  
Indole Ring ◽  
Phase Transfer Catalysts ◽  
Michael Adducts ◽  
Michael Acceptors ◽  
High Yields

An asymmetric phase-transfer-catalyzed N-alkylation of substituted indoles with various Michael acceptors was studied. Acidities of nitroindoles were determined in acetonitrile by UV-Vis spectrophotometric titration. There was essentially no correlation between acidity and reactivity in the aza-Michael reaction. The position of the nitro group on the indole ring was essential to control the stereoselectivity of the reaction. Michael adducts were obtained in high yields and moderate enantioselectivities in the reaction between 4-nitroindole and various Michael acceptors in the presence of cinchona alkaloid based phase-transfer catalysts. In addition to outlining the scope and limitations of the method, the geometries of the transition states of the reaction were calculated.

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.

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.

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).

Green Application of Phase-Transfer Catalysis in Oxidation: A Comprehensive Review

2020 ◽  
Vol 17 (4) ◽  
pp. 405-411
Author(s):  
Chuan-Hui Wang ◽  
Chen-Fu Liu ◽  
Guo-Wu Rao
Keyword(s):  
Organic Chemistry ◽  
Green Chemistry ◽  
Oxidation Reaction ◽  
Phase Transfer Catalysis ◽  
Phase Transfer ◽  
Important Application ◽  
Oxidation Reactions ◽  
Comprehensive Review ◽  
Phase Transfer Catalysts ◽  
Onium Salts

Oxidation reactions have emerged as one of the most versatile tools in organic chemistry. Various onium salts such as ammonium, phosphonium, arsonium, bismuthonium, tellurium have been used as phase transfer catalysts in many oxidation reactions. Certainly, considerable catalysts have been widely used in Phase-Transfer Catalysis (PTC). This review focuses on the application of PTC in various oxidation reaction. Furthermore, PTC also conforms to the concept of “Green Chemistry”. <p></p> • Oxidation has become one of the most widely used tools in organic chemistry and phase transfer catalysts has been widely used in oxidation. <p></p> • The application of phase transfer catalysts in oxidation reaction will be summarized. <p></p> • Phase transfer catalysts have important application in various oxidation reaction.

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.

Sign in / Sign up

Export Citation Format

Share Document