N-Boc Protection of Amines Using Silica Propyl(N-methyl) Imidazolium Chloride as an Efficient and Reusable Catalyst

A simple and efficient method for the N-Boc protection of amines using (Boc)2O in the presence of a catalytic amount of silica propyl(N-methyl) imidazolium chloride ([Sipmim]Cl) is introduced. The catalyst was efficient and reusable for this process under solvent-free conditions at ambient temperature. This methodology has several advantages in comparison with currently used methods including high yields, simple workup procedure, short reaction time, and clean and mild reaction conditions.