Carbosilanes rearrangement reactions

The formation of carbosilanes through rearrangement reactions using AICI3 is already known. This process is best illustrated by considering the transition of Si—Si—C to... 

Investigation into Ring Closure Reactions During Rearrangement Reactions of Carbosilanes... 

If the reaction temperature is low, it tends to give cyclic polysilanes (mainly the six membered ring shown in eq. (8.34), and the other products are four membered ring or eight membered ring compounds). The linear polysilanes (eq. (8.53)) are insoluble white solids. If these polysilanes are heated at 400 in the presence of B(OSiCl3)3 in a sealed system, the polymers are rearranged to form poly-carbosilanes ((-SiMe(H)—CH2-) ) as a soluble solid. 

The next stage could involve the formation of the phosphino-substituted phosphorus ylide C. Whether or not this reaction actually occurs depends on the difference in reactivity of the CCl group in the original carbosilane A, which in turn depends on the extent of Si-chlorination, compared to the PMe2Cl group in the phosphorus ylide B. As far as the phosphino-substituted ylide C is concerned, it can react with excess starting material A to yield the phosphorus ylide B, or rearrange via a competitive reaction to produce the phosphane D. The extent to which these competitive... 

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