General Last-Step Labeling of Biomolecule-Based Substrates by [12C], [13C], and [11C] Carbon Monoxide

Alkaloid-, steroid-, biotin-, carbohydrate-, nucleoside-, and peptide-based bioconjugates are easily labeled with CO by a last-step palladium-catalyzed carbonylation. The choice of the [C-12], [C-13], or [C-11] isotope opens the way to a new class of potential tracers or ligands easily available for various applications.