The reaction of buta-1,3-diene with morpholine and di-n-propylamine in the presence of NiCl₂–Ph₃P–NaBH₄, CoCI₂–Ph₃P–NaBH₄–AI(OPrⁱ)₃, and IrCI₃ has been shown to yield two isomeric 2 : 1 and 1 : 1 adducts with the former predominating. In the presence of RhCI₃ and CoCI₂–Ph₃P–NaBH₄ mainly 1 : 1 adducts were obtained. Lower conversions were found with morpholine and the nickel-containing system when the ligands di-isopropoxyphenylphosphine, tri-(o-tolyl) phosphite, and tri-(o-biphenylyl) phosphite were employed although exclusive 2 : 1 adduct formation was found with the last ligand. The addition of triphenyl-phosphine and -arsine to the RhCI₃ catalyst also favoured formation of the 2 : 1 adduct and the catalytic activity of IrCI₃ was markedly enhanced by small amounts of hydrochloric acid. Some reactions of diethylamine, pyrrolidine, and aniline have been studied. Reaction of benzyl methyl ketone and diethyl malonate with buta-1,3-diene catalysed by NiCl₂–Ph₃P–NaBH₄ yields mainly the 2 : 1 adducts. With the system CoCI₂-Ph₃P-NaBH₄, prior formation of the sodium salt of diethyl malonate was required for reaction with buta-1,3-diene.