The reaction of alpha-tetralone with various internal acetylenes can be catalyzed by Ru(H)(2)(CO)(PPh(3))(3) and gives 1:1 addition products. Symmetrically substituted dialkyl- and diaryiacetylenes gave an E/Z mixture of 1:1 coupling products in good yields. 1-Phenyl-1-butyne afforded all four possible regio- and stereoisomers. 1-Trimethylsilyl-1-propyne gave only E-isomer with C-C bond formation exclusively at the carbon atom substituted with the silyl group. Other internal acetylenes having a trimethylsilyl group also proceeded regioselectively although mixtures of stereoisomers were obtained.