The hydroamination of terminal alkyl- and arylacetylenes with aniline is catalyzed by platinum(II) bromide, yielding the corresponding imines. Contrary to what has been previously demonstrated for the platinum(II)-catalyzed hydroamination of alpha-olefins, the presence of n-BU4PBr has a detrimental effect on the course of the reaction. The hydroamination of 1-hexyne is highly regioselective (Markovnikov) at 60 degrees C, but the regioselectivity decreases upon increasing the temperature. The hydroamination of phenylacetylene is fully regioselective (Markovnikov) at 100 degrees C. TON up to 146 were obtained in the presence of a catalytic source of protons. (c) 2005 Elsevier B.V. All rights reserved.