Preparation of halogeno(pentafluorophenyl)silanes (C6F5)nSiX4−n (X=F, Cl and Br; n=2, 3) from pentafluorophenyl(phenyl)silanes (C6F5)nSiPh4−n

Halogeno(pentafluorophenyl)silanes (C6F5)nSiX4−n (X=F, Cl and Br; n=2, 3) were prepared in good yields from the corresponding phenylsilanes (C6F5)nSiPh4−n by reactions with the electrophiles aHF, FSO3H, HCl–AlCl3 or with AlX3 (X=Cl, Br)–halogenated hydrocarbons. The relative leaving ability of the organyl groups (C6F5, C6H5, Me) bonded to the silicon atom and the strength of the electrophilic reagent are discussed.