Facile organo-ruthenium(II) redox reactions with cyclic allyl halides. The characterization of a novel ruthenium(IV) intermediate in the dehydrohalogenation and dehydrogenation of 3-bromocyclohexene and the X-ray crystal structure of [(η-C5H5)Ru(η-C4H4OMe)Cl2]

Abstract

Reaction of [(η-C₅H₅)Ru(η-C₈H₁₂)X](X = Br or Cl; C₈H₁₂= cyclo-octa-1,5-diene) with the cyclic allyl halides 3-bromocyclohexene and cis-3,4-dichlorocyclobutene in alcohol solvents gives the ruthenium(IV) allyl complexes [(η-C₅H₅)Ru(η-C₆H₉)Br₂] and [(η-C₅H₅)Ru(η-C₄H₄OMe)Cl₂], the former being readily converted into the arene ruthenium(II) cation [(η-C₅H₅)Ru(η-C₆H₆)]⁺; the X-ray crystal structure of [(η-C₅H₅)Ru(η-C₄H₄OMe)Cl₂] has been determined.