Ball-Milling-Enabled Zn(OTf)₂‑Catalyzed Friedel–Crafts Hydroxyalkylation of Imidazo[1,2‑<i>a</i>]pyridines and Indoles

A facile and efficient synthetic method for the construction of C3-hydroxyalkylated imidazo[1,2-<i>a</i>]pyridines and indoles by a Zn(OTf)₂-catalyzed Friedel–Crafts hydroxyalkylation of imidazo[1,2-<i>a</i>]pyridines and indoles with carbonyl compounds under mechanochemical conditions is reported. Good product selectivity, shorter reaction time, ambient reaction temperature, tolerance of a wide range of functional groups, broad substrate scope, moderate to good yield of products, and scalability are the salient features of the developed methodology.