C(sp(3))-H Bond Activation Induced by Monohydroborane Coordination at an Iridium(III)-Phosphoramidate Complex

The reaction of Cp{*}Ir-III phosphoramidate (Cp{*} = pentamethylcyclopentadienyl) complexes with a monohydroborane (HBR2; R = cyclohexyl or mesityl) generates cyclometalated Cp{*}Ir-III complexes following two sequential intramolecular B-H and C(sp(3))-H bond-activation events. Preliminary mechanistic inquiry suggests that boron stabilization provided by the hemilabile phosphoramidate ligand provides a delta-B-H center dot center dot center dot{[}Ir] coordinated intermediate, which succumbs to borane-induced C(sp(3))-H bond activation.