Tungsten carbonyl precursors in catalyzed olefin metathesis II. Homegeneous olefin Metathesis by the RnX3‐n SnW(CO)3π‐C5H5/iBuAlCl2/O2 System

Abstract

AbstractRnX3‐nSnW(CO)3Cp (R = Me, Ph; X = Cl) precursors activated by iBuAlCl2 in the presence of oxygen in an optimal 1 October 5 ratio, show high conversion rates and a good selectivity for the 2‐pentene metathesis. The conversion rates follow the sequence Ph3Sn‐ « Me3Sn‐ < Me2ClSn‐ < Cl3Sn‐ but the tin moiety has no significant effect on the stereoselectivity for cis‐2‐pentene. There are several indications for the occurrence of competitive and successive α‐ and β‐H elimination reactions in the generation of the active tungsten carbene species.