Allenylidene-ruthenium-arene precatalyst for ring opening metathesis polymerisation (ROMP)

The ruthenium allenylidene complex [RuCl(CCCPh2)(PCy3)(p-cymene)][OTf] constitutes an excellent precatalyst for the ROMP at room temperature of norbornene (Mn=198×103, PDI=1.8) and cyclooctene (Mn=143×103, PDI=1.9). The activation of the precatalyst by initial heating (25 min, 60 °C) generates a catalytic species that operates at room temperature to produce in 10 min 90% of polyoctenamer (Mn=151×103, PDI=1.7).