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.