N‑Hydroxyimide Ugi Reaction toward α‑Hydrazino Amides

The Ugi four-component reaction (U-4CR) with N-hydroxyimides as a novel carboxylic acid isostere has been reported. This reaction provides straightforward access to α-hydrazino amides. A broad range of aldehydes, amines, isocyanides and N-hydroxyimides were employed to give products in moderate to high yields. This reaction displays N–N bond formation by cyclic imide migration in the Ugi reaction. Thus, N-hydroxyimide is added as a new acid component in the Ugi reaction and broadens the scaffold diversity.