Application of Methyl Bisphosphine-Ligated Palladium Complexes for Low Pressure N-11 C-Acetylation of Peptides

Abstract

A mild and effective method is described for ¹¹ C-labeling of peptides selectively at the N-terminal nitrogen or at internal lysine positions. The presented method relies on the use of specific biphosphine palladium-methyl complexes and their high reactivity towards amino-carbonylation of amine groups in the presence [¹¹ C]carbon monoxide. The protocol facilitates the production of native N-¹¹ C-acetylated peptides, without any structural modifications and has been applied to a selection of bioactive peptides.

Keywords: 11C-labeling; carbonylation; palladium; peptides.