Reactions of co-ordinated ligands. Part VI. The addition of hexafluoropropene, trifluoroethylene, and chlorotrifluoroethylene to tricarbonyl(diene)iron or ruthenium complexes and to tricarbonyl(o-styryldiphenylphosphine)iron

Abstract

U.v. irradiation of a solution of hexafluoropropene and tricarbonyl(buta-1,3-diene)iron, tricarbonyl(isoprene)iron, tricarbonyl(2,3-dimethylbuta-1,3-diene)iron, and tricarbonyl(cyclohexa-1,3-diene)ruthenium affords 1 : 1 π-allylic adducts, in which the fluoro-olefin links the iron atoms and the hydrocarbon chain. An X-ray crystal-structure determination of the isoprene adduct established the direction of addition as FeCF(CF₃)CF₂, and comparison of n.m.r. data suggests the same direction of addition for the other systems studied. Reaction of tricarbonyl(cyclohexa-1,3-diene)iron affords a 1 : 1 adduct formulated as an endo-CF₂·CHF(CF₃) substituted tricarbonyl(cyclohexa-1,3-diene)iron complex, a π-allylic complex in which an additional hexafluoropropene links the C₆ ring and iron atom, and a third product a tetracarbonylferracyclopentane. Related reactions of tricarbonyl(tricyclo[4.2.0]octa-1,3-diene)iron and tricarbonyl(cyclo-octa-1,3-diene)iron are reported. Similar oxidative-linking reactions occur between chlorotrifluoroethylene and tricarbonyl(2,3-dimethylbuta-1,3-diene)iron, and trifluoroethylene with tricarbonyl(cyclohexa-1,3-diene or bicyclo[4.2.0]octa-1,3-diene)iron. The reaction of tricarbonyl(o-styryldiphenylphosphine)iron with hexafluoropropene, chlorotrifluoroethylene, and trifluoroethyleno also leads to 1 : 1 adducts, formulated as ferracyclopentanes. The mechanism of formation of these compounds is discussed.