Mild and Efficient Tunable Brønsted Acidic Ionic Liquid Catalyzed O-Acetylation and O-Trimethylsilylation with Trimethylsilyl Acetate (TMSOAc) and Hexamethyldisilazane (HMDS)

This report discloses a mild and efficient O-acetylation using easily accessible TMSOAc as novel acetyl reagent O-trimethylsilylation HMDS for various alcohols catalyzed by tunable Brønsted acidic ionic liquids (TBAILs). Imidazolium-based TBAILs were prepared two-step atom-economic reaction acidities measured UV-visible spectroscopy. Both protections accomplished at room temperature with good to excellent yields, while the products separated simple work-up O-silylation column chromatography O-acetylation. Notably, post-process, catalyst in this solvent free method recovered recycled several times without significant degradation.