Gold-Catalyzed Redox Synthesis of Imidazo[1,2-a]pyridines using Pyridine N-Oxide and Alkynes

摘要

A mild, catalytic, atom economical synthesis of imidazo[1,2-a]pyridines has been developed: catalytic dichloro(2-pyridinecarboxylato)gold [PicAuCl2] in the presence of an acid produces a range of imidazo[1,2-a]pyridines in good yields starting from alkynes and 2-aminopyridine TV-oxides. This strategy is mild and foreseen to be of particular use for the installation of stereogenic centers adjacent to the imidazo[1,2-a]pyridine ring without loss of enantiomeric excess.