Friedel–Crafts alkylation of natural amino acid-derived pyrroles with CF3-substituted cyclic imines

Natural amino acid-derived ethyl 2-(1-pyrrolyl)alkanoates react with 2-trifluoromethyl-1-azacycloalkenes selectivity at the b-position of the pyrrole moiety to afford ethyl 2-[3-(1-trifluoromethyl-2-azacycloalkyl)pyrrol-1-yl]alkanoates.