Substitution reactions at silicon under strongly acidic conditions: Ligand metathesis between methyltrichlorosilane and octamethylcyclotetrasiloxane

Abstract A study of the reactions between methyltrichlorosilane (MeSiCl 3 ) and octamethylcyclotetrasiloxane (D 4 ) in the presence of trifluoromethanesulfonic acid (HOTf) showed that nucleophilic substitution in CHCl 3 solution at the trifunctional silicon was surprisingly slow in comparison with the rate of equilibration/polymerization of D 4 . The reaction rate at MeSiCl 3 was significantly faster with water present and faster still in THF. …