Enantioselective Synthesis of 2‐Substituted Indoles Bearing Trifluoromethyl Moiety by the Friedel‐Crafts Alkylation Reaction of 4,7‐Dihydroindole with <i>N</i>−H Trifluoromethyl Ketimines
Tatsuhiro Uchikura, Riku Suzuki, Yusuke Suda, Takahiko Akiyama
Abstract
Abstract The Friedel‐Crafts alkylation reaction of 4,7‐dihydroindole with N ‐unprotected trifluoromethyl ketimines by means of chiral phosphoric acid and the subsequent oxidation with DDQ afforded chiral 2‐indolylmethylamines bearing a trifluoromethyl moiety in good to high yields with excellent enantioselectivities under one‐pot conditions. The adduct was transformed without loss of enantioselectivity and the absolute stereochemistry was determined by X‐ray crystallographic analysis.
Topics & Concepts
TrifluoromethylFriedel–Crafts reactionMoietyChemistryEnantioselective synthesisAlkylationAdductMedicinal chemistryOrganic chemistryPhosphoric acidStereochemistryCatalysisAlkylFluorine in Organic ChemistryAsymmetric Synthesis and CatalysisAnalytical Chemistry and Chromatography