New Insights into the Catalytic Activity of Second Generation Hoveyda–Grubbs Complexes Having Phenyl Substituents on the Backbone

One of the most effective synthetic pathways to produce unsaturated compounds and polymers, meant for both industrial pharmaceutical applications, is olefin metathesis. These useful reactions are commonly promoted by ruthenium-based precatalysts, namely second-generation Grubbs’ catalyst (GII) complexes bearing a styrenyl ether ligand, referred as Hoveyda–Grubbs’ (HGII). By altering steric electronic characteristics substituents on backbone and/or nitrogen atoms NHC it possible increase reactivity stability ruthenium catalysts. The synthesis an HG type II complex two anti-phenyl (anti-HGIIPh-Mes) with mesityl N-substituents reported. catalytic performances new were investigated in standard ring-closing metathesis (RCM) ring-opening polymerization (ROMP) compared those analogue syn-HGIIPh-Mes classic HGII complex. A thorough analysis temperature dependence performances, along detailed comparison commercially available HGII, conducted. HGIIPh-Mes more thermally stable than their parent shown fact that activity ROMP 5-ethylidene-2-norbornene does not alter when carried out at room after have been held 180 °C hours, making them particularly interesting materials applications.