Polyfluoroalkyl compounds of silicon. Part XI. Reactions of trichloro- and of trimethyl-silane with tetrafluoro- and with 3,3,3-trifluoropropyne

Abstract

Photochemical reaction of trichlorosilane with tetrafluoropropyne gives a relatively low yield (65%) of a mixture of the 1 : 1 adducts, 1,3,3,3-tetrafluoroprop-1-enyltrichlorosilane and 2-fluoro-1-trifluoromethylvinyltrichlorosilane in the ratio 31 : 69; trimethylsilane affords a high yield of the trimethylsilyl analogues in the ratio 86 : 14. Similar reactions of trichlorosilane and trimethylsilane with 3,3,3-trifluoropropyne give, in both cases, high yields of the corresponding 3,3,3-trifluoroprop-1-enyl- and 1-trifluoromethylvinyl-silanes in the ratio 72 : 28. Fluorination of the mixture of tetrafluoropropyne–trichlorosilane adducts affords a mixture of the trifluorosilyl analogues which is stable at 300°in vacuo.