The development of alkali-metal amidinate reagents, in particular formamidinates, has proceeded hand-in-hand with fundamental advances in transition-metal bonding, e.g. metal–metal bonding, and the progressive departure from cyclopentadienyl support ligands in early transition-metal catalysis. This highly personalised account highlights the coordinative versatility of one alkali-metal amidinate subclass; the bis(aryl)formamidinates. These compounds have proven invaluable during transition-metal studies but were considered unworthy of investigation in their own right prior to our work. ; Peter C. Junk and Marcus L. Cole ; © Royal Society of Chemistry 2008