Carbon-silicon bond heterolysis

Carbon-silicon bond heterolysis of the radical-cation from trimethylsilyl-substituted ethers, thioethers, and amines, generated by PET to DCA, produces the corresponding methylene radical, which ultimately combines with reduced DCA to yield coupling products (Scheme 12) [22]. 

This leads to a significant weakening of the electron donor properties of oxygen and to a significant weakening of the electron accepting properties of the silicon. This means that the heterolysis of a siloxane bond proceeds under much more severe conditions than their carbon analogues. 

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