Iodine‐Promoted Synthesis of Dipyrazolo/Diuracil‐Fused Pyridines and o‐Amino Diheteroaryl ketones via Oxidative Domino Annulation of 2/4‐Methylazaarenes

The iodine‐promoted oxidative domino annulation and carbonylation process has been developed for the synthesis of biologically important azaarene‐substituted bis‐pyrazolo[3,4‐b:4′,3′‐e]pyridines (BPPs), diuracilpyridines and o‐amino diheteroaryl ketones. The domino procedure proceeded with easily available methyl azaarenes, 5‐aminouracils and substituted 5‐aminopyrazoles. This protocol is a simple and metal‐free approach which exhibits high functional group compatibility and broad substrates scope. Moreover, this transformation can be applied for the preparation of dipyrazolo/diuracil‐fused pyridines on a gram scale.