Vinyl sulfone-based ferrocenylation reagents: applications in conjugation and bioconjugation

The easy vinyl sulfone derivatization of ferrocene allows the preparation of some effective, versatile and valuable ferrocenylation reagents. The applicability of such compounds in conjugation and bioconjugation of amine and/or thiol containing molecules and biomolecules through Michael-type addition under mild conditions that preserve the biological function of the latter is described. The feasibility of the methodology is demonstrated by the preparation of a variety of conjugates and bioconjugates (ferrocenyl terminated dendrimers and ferrocene-sugar, ferrocene-cyclodextrin, ferrocene-peptide and ferrocene-protein conjugates).