Gold-Catalyzed C–H Bond Functionalization of Metallocenes: Synthesis of Densely Functionalized Ferrocene Derivatives

A convenient process for the direct functionalization of ferrocene that exploits the high electrophilic character of gold–vinyl carbenoids catalytically generated from vinyldiazo compounds and gold complexes is reported. This process takes place with complete regioselectivity (vinilogous reactivity). The synthesis of the corresponding ruthenocene analogues has also been achieved. Preliminary studies on the reactivity of these new organometallic compounds seem to suggest that the presence of the adjacent ferrocenyl group confers a specific reactivity on the functionalized carbon chain manifested in the easy dry state aerobic allylic oxidation.