A series of stoichiometric insertion reactions involving zirconium phosphido complexes have been explored. Simple, polar unsaturated organic molecules, including benzophenone, acetone, and benzyl nitrile, readily underwent 1,2-insertions into the zirconium–phosphorus bond of (N₃N)ZrPPh₂ (1; N₃N = N(CH₂CH₂NSiMe₃)₃^3-. This type of reactivity is highly associated with catalytic P–C bond formation in hydrophosphination and prompted investigation of catalytic hydrophosphination by triamidoamine-supported zirconium complexes. Reaction of diphenylphosphine and terminal alkynes (H–C≡C–R, R= Ph, Bu), with 5 mol % of 1 in the dark gave vinyl phosphine products according to Scheme 1. Yields of vinyl phosphines ranged from 68 – 75% as determined by ¹H and ³¹P NMR spectroscopy. In the case of phenylacetylene, a 68% yield of vinyl phosphine was observed as a mixture of isomers in an unexpected 4:1 syn to anti ratio. Competition experiments suggest that insertion of alkyne into the zirconium–phosphorus bond is a key step in this hydrophosphination, despite the facile formation of terminal alkyne complexes by ligand exchange.