First iron-catalyzed guanylation of amines: a simple and highly efficient protocol to guanidines

The first iron-catalyzed guanylation of amines is reported. Commercially available Fe(OAc)2 acts as an excellent catalyst for the addition of amines to carbodiimides. The reaction is broadly applicable to a variety of primary, secondary, and heterocyclic amines, and tolerates a wide range of functionalities allowing the easy preparation of a large family of guanidines. The low price and low toxicity of the commercially available iron catalyst make this methodology highly attractive.