EnantioselectiveFriedel–Craftsalkylations of a variety of indoles with ethyl 3,3,3-trifluoropyruvate catalyzed by novel chiral m-phenylenebis(imidazoline)-copper(II) complexes or the bis(imidazoline)-achiral acid combination afforded products with high enantioselectivity. Both enantiomers of indole derivatives can be prepared with high enantioselectivities by tuning the N-substituents of the imidazoline
A highly enantioselective Friedel–Crafts alkylation of indoles with ethyltrifluoropyruvate has been developed using N,N′-dioxide-zinc(II) complexes. Both enantiomers of the desired adducts were obtained by the use of enantiomeric ligands in excellent results (up to 99% yield and 98% ee) within 0.5 h under mild conditions. On the basis of the experimental results, a proposed working model was proposed
Brønsted Acid-Catalyzed Asymmetric Friedel–Crafts Alkylation of Indoles with Benzothiazole-Bearing Trifluoromethyl Ketone Hydrates
作者:Wei Wang、Wenhui Xiong、Jinping Wang、Qiu-An Wang、Wen Yang
DOI:10.1021/acs.joc.0c00116
日期:2020.3.20
An efficient Brønsted acid-catalyzed asymmetricFriedel-Crafts alkylation of indoles with benzothiazole-bearing trifluoromethyl ketone hydrates as electrophiles has been developed. The mild organocatalytic reactions proceeded well with lowcatalystloading to afford a range of enantioenriched α-trifluoromethyl tertiary alcohols containing both benzothiazole and indole rings with excellent yields and
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
Solkane® 365mfc is a proven environmentally benign alternative solvent for catalyst-free Friedel–Crafts (F–C) alkylations of indoles with trifluoropyruvate and glyoxylate. Their enantioselective variants are also achieved by virtue of the high-affinity of fluorous cinchona alkaloids catalysts to Solkane® 365mfc to provide F–C adducts in excellent yields with good to excellent ees (up to 96% ee).