Efficient Metathesis of Terminal Alkynes

Now even terminal: The 2,4,6-trimethylbenzylidyne complexes [MesC≡M{OC(CF(3))(2)Me}(3)] (M=Mo, W) were synthesized from [Mo(CO)(6)] and [W(CO)(6)], respectively. The molybdenum complex is an efficient catalyst for the metathesis of internal and terminal alkynes and also for the ring-closing metathesis of internal and terminal α,ω-diynes at room temperature and low catalyst concentrations.