The synthesis of trifluoromethylated 1,2-diphenylvinyl sulfone and its synthetic utilities

The treatment of 1,1-bis(phenylthio)-2,2,3,3,3-pentafluoropropylbenzene (1) with 2 equiv. of phenyllithium in THF at - 78 degrees C resulted in the fo rmation of isomeric mixture (70:30) of trifluoromethylated 1,2-diphenylviny l sulfide 2 in 87% yield. The further oxidation of 2 with m-chloroperbenzoi c acid in methylene chloride afforded isomeric mixture (70:30) of trifluoro methylated 1,2-diphenylvinyl sulfone 3 in 87% yield. When 3 was reacted wit h carbon nucleophiles such as methyllithium, n-butyllithium, phenyllithium and lithium octylide, the corresponding addition-elimination adducts 4, 5, 6 and 7 were obtained in moderate to good yields. The reaction of 3 with 4 equiv. of tributyltin hydride in benzene at reflux temperature provided iso meric mixture (90:10) of trifluoromethylated 1,2-diphenylvinyl stannane 8 i n 41% yield. The reaction of 8 with methyllithium in the presence of trimet hylsilyl chloride gave isomeric mixtures (90:10) of trifluoromethylated 1,2 -diphenylvinyl silane 9 in 88% yield. Finally, the treatment of 8 with Br-2 and I-2 resulted in the formation of isomeric mixtures (90:10) of trifluor omethylated 1,2-diphenylvinyl bromide 10 and iodide 11 in 72% and 90% yield s, respectively.