The multi-component Friedel–Crafts alkylation reaction between indole (1), ethylglyoxylate (2) and anilines (3a–f) gives, in analogy to the protocol of the old Passerini reaction, the expected ethyl 2-(arylamino)-2-(1H-indol-3-yl)acetates 4a–f. When the reactions are catalysed by 5 mol-% scandiumtriflate (ScIIITf), however, or when the isolated products 4 are treated under the same conditions, rearrangements