Résumé : The synthesis of 4′, a titanocene derivative of the anticancer drug tamoxifen is presented together with its biochemical properties. Compound 4′ is prepared by a McMurry coupling followed by a ligand exchange. Compound 4′ reveals an unexpected proliferative effect on the hormone-dependent cell line MCF7. Surprisingly this effect is also observed with Cp2TiCl2 alone. © 2002 Elsevier Science B.V. All rights reserved.