SILICON-CARBON UNSATURATED-COMPOUNDS .32. PHOTOLYSIS OF TOLYLPENTAMETHYLDISILANES AND XYLYLPENTAMETHYLDISILANES

The photolysis of ortho- and meta-tolylpentamethyldisilane (1 and 2) and 2,5- and 2,6-xylylpentamethyldisilane (3 and 4) in the presence of isobutene and acetone as trapping agents has been studied. All reactions investigated with the single exception of compound 4, afforded the 1:1 adducts derived from the silene as a result of a 1,3-silyl shift to the aryl ring with the trapping agents. The photolysis of 1 and 3 in the presence of isobutene or acetone afforded a single adduct, but 2 gave 5,6-bis(silyl)-substituted toluene and 3,4-bis(silyl)-substituted toluene, respectively. Irradiation of 4 in the presence of isobutene afforded no volatile products, while in the presence of methanol it gave methoxypentamethyldisilane and m-xylene.