Organophosphorus chemistry. Part XVII. Reaction of hexafluoropropene and some fluorochloro-olefins with phosphines: competition between radical and ionic reactions

Abstract

Dimethylphosphine reacts nucleophilically with hexafluoropropene to give trans- and cis-dimethylpentafluoropropenylphosphines in proportions which depend on the reaction conditions. These products do not arise by dehydrofluorination of a 1 : 1 adduct. The same dimethylpentafluoropropenylphosphines are also produced in good yield by the reaction of tetramethyldiphosphine with hexafluoropropene. Bistrifluoromethylphosphine failed to react with hexafluoropropropene. Dimethylphosphine gives the 1 : 1 adduct 2,2-dichloro-1,1-difluoro-ethyldimethylphosphine and 2,2-dichloro-1-fluorovinyldimethylphosphine vianucleophilic attack on 1,1-dichloro-difluoroethylene to give Me₂[graphic omitted]l₂ followed by proton transfer and loss of fluoride ion respectively. Phosphine and bistrifluoromethylphosphine give 1 : 1 adducts with 1,1-dichlorodifluoroethylene by radical reactions in which the phosphinyl radicals attack predominantly or exclusively the CF₂ group. 1-Chloro-2-fluoroethylene reacts rather inefficiently with dimethylphosphine, both nucleophilic and radical attack giving 2-chloro-1-fluoro-ethyldimethylphosphine. Radical attack by bistrifluoromethlphosphine gives 2-chloro-1-fluoroethylbistrifluoro-methylphosphine, together with several other products.