Synthesis and meta-Amination of Pyridines via Multicomponent Cascade Reaction

Abstract

We report a green, multicomponent cascade synthesis of 3-aminopyridines via [1,3′-bipyridin]-1-ium intermediates undergoing Zincke aminolysis with ammonia supported by experimental evidence and DFT calculations. The method offers broad scope (>20 examples), good functional group tolerance, and scalability in batch and flow procedures. Synthetic utility is demonstrated through conversion into 3-halo, 3-hydroxy, and 3-thiopyridines, expanding the access to meta-substituted pyridines through peripheral editing of the unprotected amino group.