Copper(II) tetrafluoroborate-catalyzed acetylation of phenols, thiols, alcohols, and amines

Abstract

Copper(II) tetrafluoroborate efficiently catalyzes acetyl­ation of structurally diverse phenols, alcohols, thiols, and amines with stoichiometric amounts of Ac₂O under solvent-free conditions at room temperature. Acid-sensitive alcohols are smoothly acetylated without competitive side reactions. The reaction is influenced by the steric and electronic factors associated with the substrate as well as the anhydride. Acetylation of a sterically hindered substrate requires excess of anhydride and longer time. Acylation with less electrophilic anhydrides affords poor to moderate yields.