The inverse electron-demand Diels-Alder reaction as a new methodology for the synthesis of 225Ac-labelled radioimmunoconjugates.

The inverse electron-demand Diels-Alder reaction between tetrazine (Tz) and trans-cyclooctene (TCO) facilitates the efficient radiosynthesis of 225Ac-labelled radioimmunoconjugates in a two-step method, outperforming conventional approaches based on isothiocyanate couplings.