ELECTRON-IMPACT STUDIES .126. ION-CYCLOTRON RESONANCE STUDIES OF ALKYLSILYL IONS .1. REACTIONS BETWEEN ALCOHOLS AND THE TRIMETHYLSILYL CATION

Nucleophilic attack of an alcohol (ROH) at the electrophilic silicon centre of the trimethylsilyl cation (Me3Si+) produces the 1:1 adduct Me3Si-O+(H)R (1). The adduct may fragment by loss of methane to yield Me3Si+-O-R; and this elimination is most pronounced when R = Me. When R ⩾ C2H5, the major decomposition pathway of (1) involves elimination of the alkene [R-H] to produce Me3Si-O+H2, which may undergo further reaction with the neutral alcohol to reform (1). The proton transfer which accompanies the elimination of [R-H] from (1) originates predominantly from C2 of the alcohol; this suggests the intermediacy of a four-membered transition state in this reaction. © 1979 Australian Journal of Chemistry, All rights reserved.