Redox noninnocence of the formazanate ligand applied to catalytic formation of α-ketoamides.

The formazan ligands have been investigated as redox-noninnocent backbones for a long time. Despite their well-established behaviour as redox reservoirs, the demonstration of catalytic efficiency governed by redox noninnocence remains elusive. We report an iron-formazanate molecule for efficiently preparing α-keto amides, where a crucial reductive cleavage of the substrate molecule is tightly regulated by the electron donation from the formazanate, in a reversible manner.