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 inhibition of reverse transcriptase (RT) of HIV-1 by non-racemic indole-based trifluoropropanoates developed by asymmetric catalysis using recyclable organocatalysts
Herein, we report the development of efficient inhibitors of reverse transcriptase (RT) of HIV-1 based on indole-alkyl trifluoropyruvate derivatives by a TZM-bl cell assay. The inhibitory activities of the two enantiomers and the corresponding racemic mixture have been compared. TZM-bl cells exhibited strong enantioselective discrimination for the (R)-configuration, among these indole derivatives, the most active compound R-12, with a 5-NO2 substituent, gave the best result when tested in the TZM-bl cells on HIV virus type HIV-1IIIB, with an EC50 value of 0.019 μM, CC50 value of 210.697 μM and SI (selectivity index, CC50/EC50) value of 11 089, respectively. The cell test showed that, in most cases, the R-enantiomer was superior to the Rac-mixture, which was better than the corresponding S-enantiomer. The results indicated that the R-enantiomer is the most favorable configuration as an efficient HIV-1 inhibitor. Molecular modeling studies suggested a structural basis for the enantioselectivity of RT towards this class of molecules.
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.
Enantioselective Friedel-Crafts alkylation of indoles with trifluoropyruvates catalyzed by chiral Cu(II) complex bearing binaphthyl-proline hybrid ligands
作者:Chao Yao、Jiaqi Hou、Qihang Cai、Yaoqi Chen、Chao Wang、Jiemian Liang、Zilin Jiao、Lin Li、Yue-Ming Li
DOI:10.1016/j.tet.2024.133874
日期:2024.3
A mild and efficient catalyst system for asymmetric Friedel-Crafts alkylation of indoles with trifluoropyruvates was reported. The chiral ligands took the advantages of both the proline and the binaphthyl moieties, and the in situ prepared Cu(II) catalyst showed good substrate tolerance in the reactions. Indoles bearing different substituents could be tolerated, and the desired products could be obtained
Chiral Brønsted Acid Catalysts. Activation of Methyl 3,3,3-Trifluoropyruvate by Hydroxymethylpyridine-Containing Half-Sandwich Complexes
作者:Daniel Carmona、Pilar Lamata、Antonio Sánchez、Pilar Pardo、Ricardo Rodríguez、Paola Ramírez、Fernando J. Lahoz、Pilar García-Orduña、Luis A. Oro
DOI:10.1021/om5005463
日期:2014.8.11
The coordinated OH group in cationic complexes [eta(n)-ring)M(NOH)(Solv)][SbF6] and [(eta(n)-ring)M(NOH)(R)-P1}][SbF6](2) ((eta(n)-ring)M = (eta(5)-C5Me5)Rh, (eta(5)-C5Me5)Ir, (eta(6)-p-MeC(6)H(4)iPr)Ru; NOH = hydroxypyridine ligand; (R)-P1 = (R)-monophos) is deprotonated by Na2CO3, rendering bi- or mononuclear compounds of formulas [(eta(n)-ring)M(kappa N-2,O-mu-O-NO}(2)][SbF6](2) and [(eta(n)-ring)M(NO)(R)-P1}][SbF6], respectively. The complexes have been characterized by analytical and spectroscopic means, including the determination of the crystal structures of [((eta(n)-ring)M(kappa N-2,O-mu-O-NO}(2)[SbF6](2) (NOH = NOH-1, (eta(n)-ring)M = (eta(5)-C5Me5)Rh, 8a; (eta(6)-p-MeC(6)H(4)iPr)Ru, 8c) and [(eta(5)-C5Me5)Ir(NO)-((R)-P1}][SbF6] (NOH = (R)-NOH-2; (R)-11b) by X-ray diffractometric methods. In complexes [(eta(n)-ring)M(NOH)(P*)1[SbF6](2) (P* = chiral phosphoramidite ligand) the proton of the coordinated hydroxypyridine ligand is able to activate the carbonyl group of methyl 3,3,3-trifluoropyruvate toward the Friedel-Crafts addition of indoles. In most cases, quantitative conversion is achieved in a few minutes, at -70 degrees C, with an ee of up to 8296. NMR data support the activation of the pyruvate by interaction between its carbonyl oxygen and the OH group of the coordinated hydroxymethylpyridine. Therefore, the metallic complexes act as Lewis acid assisted Bronsted acid catalysts.