Transfer hydrogenation; a convenient method for removal of some commonly used protecting groups in peptide synthesis

N-Benzyloxycarbonyl and benzyl ester groups in peptides can be conveniently removed by transfer hydrogenation with cyclohexene and 10% palladium–carbon catalyst. If freshly prepared palladium black catalyst is used, other commonly used protecting groups like Nτ-benzyl (histidine), benzyl ether (tyrosine, serine), and nitro (arginine) can also be removed much more rapidly than in the case of the usually employed catalytic hydrogenation.