Phosphomolybdic Acid Supported on Silica Gel as Mild, Efficient and Cost-Effective Catalyst for Chemoselective Protection of Amines with di-tert-Butyl Dicarbonate

A variety of amines were protected as their N-Boc derivatives using phosphomolybdic acid supported on silica gel as a heterogeneous catalyst. The catalyst is more effective and highly selective for the protection of amines under mild conditions and it can be recovered and reused in subsequent reactions without apparent loss of activity.