Metal-Free Synthesis of 2,4,6-Trisubstituted Pyridines via Iodine-Initiated Reaction of Methyl Aryl Ketones with Amines under Neat Heating

A neat heating protocol has been developed for metal-free synthesis of various 2,4,6-trisubstituted pyridines via iodine-initiated (in situ generated HI-catalyzed) condensation of methyl aryl ketones with amines and the following cyclization-aerobic oxidation. Large-scale synthesis and mechanistic investigation were also performed.