Unexpected Results of a Turnover Number (TON) Study Utilising Ruthenium-Based Olefin Metathesis Catalysts



A turnover number (TON) study of ruthenium-based metathesis catalysts has been conducted for ring-closing metathesis (RCM) in dilute solution. Unexpectedly the results indicate that 1st generation metathesis catalysts can give higher TON in RCM of simple unsubstituted terminal olefins than their second generation counterparts. In particular, the 1st generation Hoveyda–Grubbs catalyst showed unexpectedly high activity, particularly when compared to the 2nd generation catalysts.