Phenyliodine(III) Diacetate-Mediated 1,2-<i>ipso</i>-Migration in Mannich Bases of Imidazo[1,2‑<i>a</i>]pyridines: Preparation of <i>N</i>‑Acetoxymethyl/Alkoxymethyl‑<i>N</i>‑arylimidazo[1,2‑<i>a</i>]pyridine-3-amines

Phenyliodine­(III) diacetate -mediated 1,2-ipso-migration of an imidazo­[1,2-a]­pyridine ring via the formation of an aziridine intermediate in Mannich bases derived from imidazo­[1,2-a]­pyridines, 2-pyridylamines or arylamines, and formaldehyde is reported. The imidazo­[1,2-a]­pyridines bearing different substituents showed excellent migratory aptitude and resulted in corresponding N-acetoxymethyl-, N-alkoxymethyl-, and N-hydroxymethyl-N-arylimidazo­[1,2-a]­pyridine-3-amine derivatives in moderate to excellent (42 examples; 35–93%) yields. Radical trapping experiments confirmed the involvement of a non-radical intermediate. The developed protocol is amenable for a scale-up reaction, and synthetic utility of N-acetoxymethyl products was demonstrated by transforming them to corresponding N-(pyridin-2-yl)­imidazo­[1,2-a]­pyridin-3-amines.