Iron-Catalyzed Acyl Migration of Tertiary α-Azidyl Ketones: Synthetic Approach toward Enamides and Isoquinolones.

This paper reports that tertiary α-azidyl phenyl ketones can be transformed into enamides by treatment with FeBr2 at elevated temperature in DMF. The reaction proceeds via 1,2-benzoyl migration from α-carbon to the nitrogen atom, accompanied by expulsion of a nitrogen molecule. This protocol is suitable for the synthesis of N-(cyclopent-1-en-1-yl)benzamides, N-(cyclohex-1-en-1-yl)benzamides, and N-benzoyl-α-methyl enamines and provides a convenient approach toward isoquinolones.