Reductive Elimination, and Other Reactions

The disproportionation equilibrium (107) is common among silicon compounds, especially hydrides and fluorides (22, 24) the right-hand 

Disproportionation about the transition metal is much less common one example involves a silyl iron hydride 259). 

It is useful to gather together under this heading a number of reactions of compounds in which an RgSi group and a hydrogen atom are attached to the same transition-metal center  

These may be described either as a type of Si-M cleavage reaction or as a migration of hydrogen from metal to silicon. Clearly they represent the reverse process to the well-known oxidative addition reaction discussed in Section II,F. 

Compounds of the class R3SiMnH(CO)2(Cp) have been mentioned already in this connection 117-119, 225, 259) (Ihble X, entries 12, 13, 63, and 87). Reactions with tertiary phosphines, chlorine, methyl-lithium, or an excess of HCl all lead to elimination of RgSiH ( deinsertion ), as in 

---