Reactions of dimethyl-, diphenyl-, and (chloromethyl) methyldiallylsilanes with acetic, trifluoroacetic, triflic acids and complex BF3· 2AcОH are studied. Depending on the structure of the starting diallylsilane and the nature of the electrophilic reagent the following processes are realized: addition of an electrophile to one СС bond; expulsion of one or two molecules of propene with addition of the electrophile residue to the silicon atom; and ...