Ruthenium Catalyzed Hydrohydroxyalkylation of Isoprene with Heteroaromatic Secondary Alcohols: Isolation and Reversible Formation of the Putative Metallacycle Intermediate

Heteroaromatic secondary alcohols
react with isoprene to form products
of hydrohydroxyalkylation in the presence of ruthenium(0) catalysts
generated from Ru3(CO)12 and tricyclohexylphosphine,
enabling direct conversion of secondary to tertiary alcohols in the
absence of premetalated reagents or stoichiometric byproducts. The
putative oxaruthenacycle intermediate has been isolated and characterized,
and reversible metallacycle formation has been demonstrated.