Electrochemically reduced tungsten-based active species as catalysts for cross-metathesis reactions:: cross-metathesis of non-functionalized olefins

The electrochemical reduction Of WCl6 results in the formation of an active olefin (alkene) metathesis catalyst. The application of the WCl6-e(-)-Al-CH2Cl2 catalyst system to cross-metathesis reactions of non-functionalized acyclic olefins is reported. Undesirable reactions, such as double-bond shift isomerization and subsequent metathesis, were not observed in these reactions. Cross-metathesis of 7-tetradecene with an equimolar amount of 4-octene generated the desired cross-product, 4-undecene, in good yield. The reaction of 7-tetradecene with 2-octene, catalyzed by electrochemically reduced tungsten hexachloride, resulted in both self- and cross-metathesis products. The cross-metathesis products, 2-nonene and 6-tridecene, were formed in larger amounts than the self-metathesis products of 2-octene. The optimum catalyst/olefin ratio and reaction time were found to be 1: 60 and 24 It, respectively. The cross-metathesis of symmetrical olefins with alpha-olefins was also studied under the predetermined conditions. Copyright (C) 2003 John Wiley Sons, Ltd.