The bis(phosphino)pyridine (PNP) cobalt(I) methyl complex, (iPrPNP)CoCH3 is a rich platform for the oxidative addition of non-polar reagents such as H2, the C–H bonds of arenes and terminal alkynes. Rare examples of hexacoordinate cobalt(III) compounds including a trihydride, a bis(acetylide) hydride and a trimethyl complex have been isolated and two examples structurally characterized. These findings demonstrate that when placed in an appropriately strong ligand field, two-electron oxidative addition chemistry is possible with first row transition metals.
