The mechanism of solvolysis of 2-halogenoalkylsilanes. Part II. Deuterium isotope effects

Abstract

The compounds Me₃Si·CH₂·CD₂Br, Me₃Si·CHD·CH₂Br, and (CD₃)₂MeSi·CH₂·CH₂Br have been prepared and their solvolysis rates in aqueous ethanol have been determined and compared with those for the non-deuteriated compounds. The acid-catalysed solvolysis of the 2-hydroxyalkylsilanes is similar to the solvolysis of 2-halogenoalkylsilanes and it appears likely that it follows a similar mechanism. The compound Me₃Si·CH₂·CD₂·OH was prepared and its rate of solvolysis was determined and compared with that of the non-deuteriated material in the same medium. The mechanism of the solvolysis reaction is discussed in the light of the observed isotope effects and the stereochemical evidence reported previously.