A Comparison of the Activity of Homogeneous Tungsten and Ruthenium Catalysts for the Metathesis of 1-Octene

✍ Scribed by C. van Schalkwyk; H. C. M. Vosloo; J. A. K. du Plessis

• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 178 KB
• Volume: 344
• Category: Article
• ISSN: 1615-4150
• DOI: 10.1002/1615-4169(200208)344:6/7<781::aid-adsc781>3.0.co;2-8

✦ Synopsis

The W(O-2,6-C 6 H 3 X 2 ) 2 Cl 4 /Bu 4 Sn catalytic systems (X Ph, F, Cl, Br) have a high activity for the metathesis of terminal alkenes and a high selectivity towards primary metathesis products. Tungsten(VI) alkoxide complexes are not nearly as active as the tungsten(VI) aryloxide complexes. Br˘nsted acids such as HOAc, BuOH and H 2 O deactivate both the W(O-2,6-C 6 H 3 X 2 ) 2 Cl 4 /Bu 4 Sn (X Cl and Ph) catalytic systems. The Lewis base (BuOAc) showed no deactivation of the catalytic systems. The Grubbs catalyst, RuCl 2 (PCy 3 ) 2 ( CHPh), is very active for the metathesis of 1-alkenes, even at an alkene/Ru molar ratio 100,000. Selectivities > 93% were generally obtained. The ruthenium catalyst is active at low temperatures (25 8C) and high temperatures (130 8C). It shows a high tolerance towards oxygen-containing additives. The polarity of the solvent plays a major role in the activity and also the selectivity of especially the W(O-2,6-C 6 H 3 X 2 ) 2 Cl 4 /Bu 4 Sn catalytic systems.