Enhanced efficiency of recyclable C3-symmetric cinchonine-squaramides in the asymmetric Friedel–Crafts reaction of indoles with alkyl trifluoropyruvate
摘要:
The highly enantioselective Friedel-Crafts reaction of indoles with trifluoropyruvate catalyzed by a C-3-symmetric cinchonine-squaramide is reported. A wide variety of trifluoromethylated indole derivatives were obtained in high yields and with excellent enantioselectivities (99% and up to > 99% ee). Moreover the C-3 catalyst can be easily recovered and was used five times. (C) 2012 Elsevier Ltd. All rights reserved.
Asymmetric Friedel–Crafts Alkylation of Indoles with Trifluoromethyl Pyruvate Catalyzed by a Dinuclear Zinc Catalyst
作者:Yuan-Zhao Hua、Jun-Wei Chen、Hua Yang、Min-Can Wang
DOI:10.1021/acs.joc.7b02599
日期:2018.2.2
cooperative catalysis model has been reported for the asymmetric Friedel–Crafts (F–C) alkylation of indoles with trifluoromethyl pyruvates using Trost’s intramolecular dinuclear zinc complex as the catalyst. This dinuclear zinc catalyst was prepared in situ by reacting the chiral ligand (S,S)-L2b with 2 equiv of ZnEt2. A series of trifluoromethyl alcohol and indole-containing biological compounds were formed
Enantioselective Friedel−Crafts Alkylation Reactions Catalyzed by a Chiral Nonracemic <i>C</i><sub>2</sub>-Symmetric 2,2‘-Bipyridyl Copper(II) Complex
作者:Michael P. A. Lyle、Neil D. Draper、Peter D. Wilson
DOI:10.1021/ol050075d
日期:2005.3.1
EnantioselectiveFriedel-Craftsalkylation reactions of a series of substituted indoles with methyl trifluoropyruvate, catalyzed by a chiral nonracemic C(2)-symmetric 2,2'-bipyridyl copper(II) triflate complex, are described. The corresponding 3,3,3-trifluoro-2-hydroxy-2-indole-3-yl-propionic acid methyl esters were formed in good yield and in high enantiomeric excess (up to 90%). This is the first
Indoles, and pyrroles, and furans, oh my! Chiral phosphoric acidcatalyzed Friedel–Crafts alkylation of indoles with 3,3,3‐trifluoropyruvate gave the corresponding adducts in excellent yields with high enantioselectivities. Electron‐deficient indoles, in particular, exhibited excellent enantioselectivities.
Asymmetric Friedel-Crafts Reaction of Indoles with Ethyl Trifluoropyruvate Using a Copper(I)-Bisoxazolidine Catalyst
作者:Christian Wolf、Peng Zhang
DOI:10.1002/adsc.201000918
日期:2011.3.28
Bisoxazolidine 1 is an effective ligand in the copper(I)‐catalyzed Friedel–Craftsreaction of alkyl trifluoropyruvates and indoles. A range of ethyl 2‐(3′‐indolyl)‐3,3,3‐trifluoro‐2‐hydroxypropanoates was produced in up to 99% yield and 94% ee within 30 min to 4 h. The effect of temperature on conversion and enantioselectivity proved to be substrate specific and was optimized individually. Of particular
Heterogeneously Organocatalytic, Enantioselective Friedel-Crafts Alkylation of Indole with 3,3,3-Trifluoropyruvate
作者:Pei Wang、Jinhui Ni、Yong An、Xiaojiang Chen、Weiwei Zhang、Yang Zhang、Guorong Ma
DOI:10.3987/com-21-14566
日期:——
amine-squaramide catalyst was synthesized with diphenylethylenediamine as the chiral framework and successfully catalyzed the asymmetric Friedel-Craftsalkylation reaction between indole and trifluoropyruvate. A series of trifluoromethylated indole derivatives were obtained with high yield (up to 95%) and moderate to good enantioselectivity (up to 76% ee). The reaction proceeds in heterogeneoussystem, the catalyst