Chloroplatinic acid catalyzed additions of silanes to isoprene

The chloroplatinic acid catalyzed hydrosilylation of isoprene with trichlorodichloromethyl-, and trimethylsilane has been reinvestigated with the purpose of establishing the mode of addition to the substrate. This was accomplished by identifying the structures of the $\text{1}\text{1}$ adducts, their methylated derivatives and the saturated analogs of the latter. Trichlorosilane added 1,4 to the less hindered side of isoprene; dichloromethylsilane added both 1,2 and 1,4 to the less hindered side and trimethylsilane added 1,2 and 1,4 to both sides of isoprene. These results are contrary to those previously reported in the literature.