Synthesis of functionalized indoles with a trifluoromethyl-substituted stereogenic tertiary carbon atom through an enantioselective Friedel-Crafts alkylation with β-trifluoromethyl-α,β-enones

摘要

Chiral complexes of BINOL-based ligands with zirconium tert-butoxide catalyze the Friedel-Crafts alkylation reaction of indoles with β-trifluoromethyl-α,β-unsaturated ketones to give functionalized indoles with an asymmetric tertiary carbon center attached to a trifluoromethyl group. The reaction can be applied to a large number of substituted α-trifluoromethyl enones and substituted indoles. The expected products were obtained with good yields and ees of up to 99%.