Co-catalyst dependent cycloisomerization or ring closing metathesis of α,ω-dienes catalyzed by arene ruthenium complex with side-arm alcohol

Cycloisomerization and ring closing metathesis of some α,ω-dienes were catalyzed by a cationic arene ruthenium chelate complex [Ru{η6:η1-Ph(CH2)3OH}(PCy3)Cl]BF4 (1a) in the presence of triethylamine and phenylacetylene, respectively, as co-catalysts. Analogous catalyst systems employing arene ruthenium cations without the side arm alcohol functional group showed lower efficiencies.