Reaction of the N-heterocyclic carbene-stabilized phosphinoaminosilylene ArN(SiMe3)Si(I'Pr)PPh2 (Ar = 2,6-'Pr2C6H3, I'Pr = 1,3-diisopropyl-4,5-dimethyl-imidazol-2-ylidene) (2) with dioxygen resulted in the formation of the two products ArN = Si(I'Pr)(OSiMe3)(OPPh2) (3) and ArN = Si(I'Pr)(OSiMe3)PPh2 (4), and the ratios of the two products can be controlled by the reaction temperatures and dioxygen concentrations.