Olefin Metathesis

The homogeneous olefin metathesis of 2-heptene with a catalyst system of WCl6-Bu4Sn was investigated. The optimum ratios of Bu4Sn to WCl6 were in the wide range of 1.02.0, and the Friedel-Crafts products were less than 3% when the ratios were more than 1.0. The addition of ether to the reaction medium has a relatively little influence on the catalyst activity. Bu3SnCl and Bu2SnCl2 were not effective as the cocatalyst and the decrease of the conversion with the excess amount of Bu4Sn was not significant. It therefore seems likely that Bu4Sn can provide only one alkyl group for the substitution of WCl6 and the substitution attains equilibrium in the first step of the catalyst formation.