A catalytic system consisting of RUCl3 hydrate, a phosphine and an alkyne were investigated for the metathesis of 1-octene. Hydrogen was used during the reaction to obtain the highest yield of primary metathesis products. The influence of additives (oxygenates) was investigated and the reaction conditions optimized. Metathesis of 1-octene shows the best results at temperatures between 80 and 90degreesC if acetic acid or ethanol was used as solvent and a PCy3/Ru molar ratio of 1. It was also found that both internal and terminal alkynes could be used for the in situ activation of the metathesis precursor during metathesis reactions. (C) 2002 Elsevier Science B.V. All rights reserved.