Silica supported perchloric acid (HClO4–SiO2): an efficient reagent for the preparation of primary carbamates under solvent-free conditions

The synthesis of primary carbamates from structurally diverse compounds containing a hydroxyl group has been performed in high yields and purity, and without any epimerization under solvent-free conditions using HClO4–SiO2 as a mild, convenient, and effective reagent. The procedure is operationally simple, efficient, and environmentally benign.