Mechanistic study of arylsilane oxidation through (19)F NMR spectroscopy

摘要

The mechanism of the oxidation of arylsilanes to phenols has been investigated using (19)F NMR spectroscopy. The formation of silanols in these reactions results from a rapid background equilibrium between silanol and alkoxysilane; the relative rates of reaction of these species was evaluated by modeling of concentration profiles obtained through (19)F NMR spectroscopic reaction monitoring. Combining these results with a study of initial rates of phenol formation, and of substituent electronic effects, a mechanistic picture involving rapid and reversible formation of a pentavalent peroxide ate complex, prior to rate-limiting aryl migration, has evolved.