Reactions of silyl cations with ketones in the gas phase

In the gas phase, (CH(3))(3)SiOSi(+)(CH(3))(2) and (CH(3))CH(2)SiOSi(+)(CH(3))(2) ions 1 and 2 were formed in the external source of a Fourier transform ion cyclofrom resonance (FT-ICR) spectrometer by electron impact ionization of (CH(3))(3)SiOSi(CH(3))(3). In the FT-ICR cell, the electrophilic center of these ions reacts with acetone to give product ions whose structures are probed by comparison with those of the products formed by reaction with water. The mechanisms of formation of these products, studied by labeling, involve facile 1,3-methyl transfer from silicon to silicon and cyclic intermediates. Copyright 1999 John Wiley & Sons, Ltd.