Neutral and Ionic Cycloruthenated 2-Phenylindoles as Cytotoxic Agents

The synthesis and characterization of two families of cyclometalated Ru(II) complexes with the new (C-sp2,N-indole)(-) motif formed by activation of the C-H bonds of 2-phenylindole ligands of the general formula {(4'-R'-C6H4)-3-NOMe-5-R-2-6-R-3-(C6H2N)}are presented. The novel ruthenacycles show a remarkable cytotoxic activity in MCF7 and MDA-MB231 breast cancer cell lines, which clearly exceeds those of the trans and cis isomers of [PtCl2(L)(DMSO)] derived from the same ligands and even that of cisplatin.