Reactions of a Highly Crowded Triorganotin Iodide with Silver Salts. Migration of a Methyl Group from Silicon to Tin within a Cation

Reaction of the highly crowded organotin iodide with AgBF4 gives the fluoride
Reaction with AgOSO2C6H4Me followed by workup in moist air gives the hydroxide 2f. With AgOSO2CF3 the product is the
organosilicon trifluoromethanesulfonate 5, formed apparently by an unprecedented 1,3-migration of a methyl group from
silicon to tin within a cation. Compound 5 and Ph3SiOSO2CF3 are the first silicon
trifluoromethanesulfonates to be characterized by X-ray structure determinations. In both
the Si−O bonds are long, ca. 1.75 Å, consistent with the ready nucleophilic displacement of
[OSO2CF3]- from silicon centers. The crystal structures of the fluoride and the hydroxide 2f have also been determined.