The reactivity of intermediate zinc hydride 2 towards a range of unsaturated C=C bonded substrates was investigated. Alkynes readily underwent hydrozincation using 2, as did terminal alkenes, while internal alkene substrates were generally more sluggish to react. Hence reaction of 2 with oct-4-yne cleanly forms 3b. Reaction of 2 with 1-phenyl-1-propyne at 80 °C resulted in formation of a mixture of two regioisomeric hydrozincation products, 3c and 3d in an approximately 1:1 ratio, 56% yield. The reaction of 2 with 1,4diphenybutadiyne led to the selective hydrozincation of one of the alkynyl groups to yield 3e, in this case only a single regioisomer was observed in quantitative yield at 80 °C. Reactions of 2 with terminal alkenes 1-allylbenzene and hex-1-ene at 80 °C also formed the corresponding zinc alkyl compounds 3f and 3g, respectively (Scheme 2).