Revisiting Iodine-mediated N-tert-Butoxycarbonylation of Amines

Revisiting the iodine mediated N-Boc (N-tert-butoxycarbonyl) protection of amines revealed that the reaction can be performed using a lower quantity of iodine as a catalyst within a shorter reaction time. In addition to various aliphatic and aromatic amines the reaction was found to be equally effective and selective for the N-Boc protection of amino acid, guanidine, thiourea and N-(diaminomethylene)-1,1,1-trifluoromethanesulfonamide. The operational simplicity, high yield, mild and solvent free nature are the other features of this process. In addition to reassessing the reported reaction conditions and duration our study also demonstrates the further generality and versatility of this process.