A convenient approach for the preparation of imidazo[1,2-a]-fused bicyclic frameworks via IBX/NIS promoted oxidative annulation†
An IBX/NIS-induced intramolecular oxidative annulation of Mannich-type substrates is reported. This metal-free approach involving iodination, NH-oxidation, intramolecular C–N bond formation, and retro-Claisen–Schmidt sequence provides the construction of imidazo[1,2-a]pyridine, imidazo[1,2-a]pyrimidine as well as imidazo[1,2-a]pyrazine frameworks with yields up to 93%. In addition, a sequential one-pot process is also presented.
- This article is part of the themed collection: Synthetic methodology in OBC