The addition of free radicals to unsaturated systems. Part XV. Further investigation of the direction of radical addition to chloro-1,1-difluoroethylene

Abstract

Photochemical reaction of chloro-1,1-difluoroethylene with trifluoroiodomethane gives a 92% yield of the 1 : 1 adducts 3-chloro-1,1,1,2,2-pentafluoro-3-iodopropane and 2-chloro-1,1,1,3,3-pentafluoro-3-iodopropane in the ratio 92 : 8. The major by-product is 1,1-difluoroiodoethylene. Reaction at 225° gives a low yield of the same 1 : 1 adducts (ratio 98 : 2). Irradiation of 3-chloro-1,1,1,2,2-pentafluoro-3-iodopropane gives as major products trifluoroiodomethane, chlorotrifluoromethane, and 1,1-difluoroiodoethylene. The photochemical reaction of hydrogen bromide with chloro-1,1-difluoroethylene results in the exclusive formation of 1-bromo-2-chloro-1,1-difluoroethane.