Ruthenium Catalyst with a Chelating Pyridinyl‐Alcoholato Ligand for Application in Linear Alkene Metathesis

The catalytic activity of ruthenium alkylidene complexes [RuCl(L)( $\widehat{ON}$ )(CHPh)] [L=H 2 IMes and PCy 3 , $\widehat{ON}$ =1‐(2′‐pyridinyl)cyclohexan‐1‐olate)], bearing a chelating pyridinyl‐alcoholate ligand, was investigated for the metathesis of 1‐octene in the absence of a solvent. Both systems were active for the metathesis of 1‐octene yielding trans ‐7‐tetradecene and ethene as the primary metathesis products. Although the activity of both systems increased with an increase in reaction temperature, the activity of [RuCl(H 2 IMes)( $\widehat{ON}$ )(CHPh)] started to decrease at temperatures above 70 °C, with a simultaneous exponential increase in the secondary metathesis products due to double‐bond isomerisation of the substrate. Although the initiation rates for these systems are slower compared to Grubbs 1 and Grubbs 2 for the metathesis of 1‐octene at 60 °C, they have a higher activity and longer lifetime.