Access to Thioglycoconjugate Bioorganometallic Ferrocenes via a Copper-Catalyzed Coupling

The synthesis of thiosugar-ferrocene conjugates through Ullmann-type coupling is reported. The method provides access to compounds showing direct attachment of the thiol to the ferrocene, a type of molecule of which only one example had previously been reported. This methodology, which has been extended to other thiols (alkyl, (hetero)aryl), enables products to be obtained in excellent yields under relatively mild operating conditions. Several of these compounds have been tested against HTC116 cells without yielding convincing results, the best IC₅₀ remaining at the micromolecular level.