Oxidative Coupling of Guanidines and Isocyanides Catalyzed by Nickel(II): Access to Imidazoline Derivatives with Antibacterial Activity.

A novel and concise approach to rare 2,3,5-triamino-imidazole scaffolds via Ni-catalyzed coupling of alkylisocyanides and N,N'-diarylguanidines has been developed. This reaction features include mild conditions (thermal or visible light activation), a wide substrate scope, and high efficiency. The coupling proceeds through a Ni/Ni catalytic cycle, involving two-electron aerobic oxidation and the sequential insertion of two isocyanide units into Ni-N bonds.