Reaction of hexafluorobut-2-yne with carbonyl complexes of iron, ruthenium, and osmium

Abstract

U.v. irradiation of a hexane solution of trans-(CO)₃L₂Fe [L =(EtO)₃P or PhMe₂P] and excess of hexafluorobut-2-yne gave (CO)₂(L)Fe[(CF₃)₄C₄CO], a cyclopentadienone compound. A similar reaction with trans-(CO)₃-[(MeO)₃P]₂Ru gave a metalocyclopentadiene (CO)₂[(MeO)₃P]₂[graphic omitted], whereas, trans-(CO)₃(PhPMe₂)₂Ru afforded (CO)₂[PhPMe₂]₂[graphic omitted] and (CO)₃[PhPMe₂][graphic omitted] the latter being a mixture of stereoisomers. Reactions of trans-(CO)₃[(MeO)₃P]₂Ru with one mole equivalent of hexafluorobut-2-yne gave a compound which is formulated as a metalocyclobutenone, (CO)₂[MeO)₃P]₂[graphic omitted]. The metalocyclopentadiene (CO)₂[(MeO)₃P]_2–[graphic omitted] reacts with more hexafluorobut-2-yne to afford dicarbonyl(trimethyl phosphite)-1,2,3,4-tetrahapto-hexakistrifluoromethylbenzeneruthenium. The osmium compound trans-(CO)₃[(MeO)₃P]₂Os reacts with an excess of hexafluorobut-2-yne to give only (CO)₂[(MeO)₃P]₂Os[CF₃C₂CF₃]. The mechanism of these reactions is briefly discussed.