Piano Stool Aminoalkylidene‐Ferracyclopentenone Complexes from Bimetallic Precursors: Synthesis and Cytotoxicity Data

Abstract

Abstract The reaction of pyrrolidine with a series of cationic diiron cyclopentadienyl complexes containing a bridging vinyliminium ligand gives access to piano stool monoiron complexes based on a five‐membered metallacycle that includes a vinyl‐aminoalkylidene moiety, in moderate to high yields. The resulting metallacyclic motif (aminoalkylidene‐ferracyclopentenone) is unique in organometallic chemistry and is partially pre‐constructed on the dinuclear frame. The monoiron products were fully characterized by elemental analysis, IR and multinuclear NMR spectroscopy, and in a number of cases by X‐ray diffraction and cyclic voltammetry. They are robust in aqueous solutions and generally unreactive towards alkylating agents in organic solvents. However, a cationic derivative was prepared in high yield by methylation of a 2‐pyridyl group. The cytotoxicity of both neutral and ionic complexes was assessed on cancerous (A2780 and A280cisR) and non‐cancerous (HEK293) cell lines, revealing the influence of local structural modifications on the antiproliferative activity and the selectivity of the compounds.