Catalytic removal of N-allyloxycarbonyl groups using the [CpRu(IV)(pi-C3H5)(2-quinolinecarboxylato)]PF6 complex. A new efficient deprotecting method in peptide synthesis

A variety of amines including even sterically less demanding and highly nucleophilic secondary amines have been efficiently deprotected without decarboxylative N-allylation from the corresponding N-allyloxycarbonyl (N-AOC) compounds by using a catalytic amount of CpRu(IV)(pi-C3H5)(2-quinolinecarboxylato)]PF6 in the presence of 1 molar amount of trifluoromethanesulfonic acid, the general utility of which has been demonstrated by the efficient synthesis of a collagen protein unit tripeptide, Pro-Pro-Gly.