Synthetic approach to ruthenium vinylidene complexes and their applications in metathesis catalysis

Convenient routes for synthesis of ruthenium vinylidene complexes have been described, the majority of which use alkynes along with a ruthenium source as the main starting materials. Their successful application as efficient precatalysts in synthesis of heterocyclic and carbocyclic compounds by ring-closing metathesis of alpha,omega-dienes and in the synthesis of polymers by ring-opening metathesis polymerization of cyclooctene, norbornene, 5-substituted norbornene and dicyclopentadiene are fully illustrated. Relevant aspects concerning the activity and stereoselectivity in metathesis reactions of this type of Ru complexes are highlighted