Iron-Catalyzed Asymmetric Nitro-Mannich Reaction.

The first enantioselective addition of nitroalkanes to imines (nitro-Mannich reaction), mediated by an iron(II) catalyst assembled by a hindered hydroxyethyl-pybox ligand, is described. This valuable carbon-carbon bond-forming reaction proceeds smoothly at room temperature to afford enantioenriched β-nitro amines in good yields and high enantioselectivity, up to 98% with unprecedentedly low iron catalyst loading (5 mol %).