1- Octene, reaction with ruthenium complexes

Other transition-metals have also been used. For example, Trost183 reported that heating a 1 1 mixture of 1-octene and 1-octyne in DMF-water (3 1) at 100°C with a ruthenium complex for 2 h generated a 1 1 mixture of two products corresponding to the addition of the alkene to the acetylene (Eq. 3.47). The presence of a normally reactive enolate does not interfere with the reaction. 

The preparation of the catalyst starts with the synthesis of 1-mes-ityl-3-(7-octene)-imidazole bromide. This compound is prepared by condensing mesityl imidazole with 8-bromooctene. The resulting salt is deprotonated with (TMS)2NK, where TMS is the tetrameth-ylsilyl radical. This step is performed in tetrahydrofuran at -30°C for 30 min. To this product a solution of the ruthenium complex (PCy3)2Cl2Ru=CHPh is added at 0°C. Bringing the solution slowly to room temperature, after 1 h the ligand displacement was determined to be complete. Afterwards, the reaction mixture is then diluted with n-pentane and heated to reflux for 2 h to induce intramolecular cyclization. 

With methyl oleate, 53% yield of the terminal alcohol was observed. With unmodified internal olefins (2-decene, 2-tridecene, 4-octene), even higher regioselectivities in favor of the terminal alcohol could be achieved l/b up to 12 1). Proof was given that both rhodium and ruthenium complexes catalyze the isomerization-hydroformylation-hydrogenation reaction in a cooperative manner. 

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