Hiyama coupling alkenylsilanes

Alkenylsilanes. Addition of (MesS sSiH to 1-alkynes in the presence of a Rh(I) complex furnishes the ( )-l-silylalkenes, whereas the (Z)-isomers are obtained from formal group exchange reaction starting from (Z)-l-alkenyl sulfones. These alkenylsilanes can be used in Hiyama coupling after treatment with alkaline H2O2. 

Transmetallation of alkenylsilanes takes place with retention of the double bond configuration, as in other cross-coupling reactions [295]. Owing to the lower transmetallation rate, competing 1,2-insertion of the alkene in the intermediate organopalladium complex (as a Heck type reaction) may take place, which affects the regioselectivity of the Hiyama reaction in some cases (Scheme 1.38) [296]. This... 

---