Cyclopentadienylsodium and Phenylethynylsodium as Cocatalysts in Olefin Metathesis

Abstract
Cyclopentadienylsodium and phenylethynylsodium are effective cocatalysts with WCl6 in the homogeneous olefin metathesis. The optimum mole ratios of C5H5Na and PhC≡CNa to WCl6 ranged more widely—from 1.5 to 3.0 and from 1.5 to 2.5 respectively—than that of BuLi to WCl6. The formation of the Friedel-Crafts products was extremely small—such as 1—%, if the cocatalyst/WCl6 ratio was about 2. The new catalyst systems were less poisoned by ether than the other catalyst systems and were hardly deactivated in the course of the reaction. The characteristics of these catalyst systems were discussed.