Fe-catalyzed regioselective Friedel–Crafts hydroxyalkylation of N-substituted glyoxylamide with indoles

An efficient regioselective Friedel–Crafts hydroxyalkylation of N-substituted glyoxylamide with various indoles catalyzed by Lewis acids was developed. The reactions proceeded smoothly at room temperature and the 2-hydroxy-2-(1H-indol-3-yl)-N-substituted acetamide resulted from the reactions catalyzed by FeSO4 were synthesized in excellent yields (up to 93%). While the bisindole compounds were obtained when FeCl3 was used as a catalyst in excellent yields (up to 92%). A possible mechanism was proposed.

Graphical abstractAn efficient regioselective Friedel–Crafts hydroxyalkylation of N-substituted glyoxylamide with various indoles catalyzed by Lewis acids was developed.Figure optionsDownload full-size imageDownload as PowerPoint slide