Coordinatively unsaturated ruthenium allenylidene complexes: highly effective, well defined catalysts for the ring-closure metathesis of α,ω-dienes and dienynes

Abstract

The well defined, conveniently accessible and coordinatively unsaturated allenylidene complexes [RuCl₂(CC CPh₂)(PCy₃)₂] and [Ru₂Cl₄(CCCPh₂)(PCy₃)(η-MeC₆-H₄Prⁱ-4)] are highly effective catalysts for the ambient temperature ring-closure metathesis of α,ω-dienes and dienynes, illustrated by the facile and high yielding formation of variously functionalised 5, 6, 7, 8, 15, 16 and 18 membered mono- and bi-cyclic ring systems.