Zn(OTf)(2)-catalyzed addition of amines to carbodiimides: efficient synthesis of guanidines and unpredicted formation of Zn-N amido species.

Zn(OTf)(2) acts as an excellent catalyst precursor for addition of various amine N-H bonds to carbodiimides under an atmosphere of air, offering a convenient synthesis of substituted guanidines with high functional-group tolerance. A Zn-N amido species is shown to act as the active species.