Asymmetric Friedel-Crafts reactions of N-tert-butylsulfinyl-3,3,3-trifluoroacetaldimines: general access to enantiomerically pure indoles containing a 1-amino-2,2,2-trifluoroethyl group.

We have demonstrated that 3,3,3-trifluoroacetaldimine (S)-1 easily reacts with indole derivatives under Friedel-Crafts reactions to provide reliable and generalized access to biologically interesting compounds containing the CF3CH(NH2)- pharmacophoric group. The reactions proceed with high rates and generally excellent yields (>90%) and stereochemical outcomes (99:1 dr).