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.