Imino- and Amido-Pyridinate d-Block Metal Complexes in Polymerization/Oligomerization Catalysis. In: Campora J, Giambastiani G, editors. Olefin Upgrading Catalysis by Nitrogen-based Metal Complexes I. Dordrecht: Springer Netherlands; 2011. pp. 197-281. [DOI: 10.1007/978-90-481-3815-9_5]

Novel half-sandwich iridium(iii) imino-pyridyl complexes showing remarkable in vitro anticancer activity

Seven novel half-sandwich Ir^III cyclopentadienyl complexes, [(η⁵-Cp^x)Ir(N^N)Cl]PF₆, have been prepared and characterized, where Cp^x is Cp* or the biphenyl derivative Cp^xbiph (C₅Me₄C₆H₄C₆H₅), and the N^N-chelating ligands are imino-pyridyl Schiff-bases. The X-ray crystal structures of complexes 2A, 2B, and 3A have been determined. Excitingly, most of the complexes show potent antiproliferative activity towards A549 and HeLa cancer cells, except for Cp* complex 1A towards HeLa cells. Cp^xbiph complex 2B displayed the highest potency, about 19 and 6 times more active than the clinically used drug cisplatin toward A549 and HeLa cells, respectively. These complexes undergo hydrolysis, and the kinetics data have been calculated. DNA binding has been studied by interaction with nucleobases 9-ethylguanine and 9-methyladenine, cleavage of plasmid DNA, and interaction with ctDNA. Interaction with DNA does not appear to be the major mechanism of action. Protein binding (bovine serum albumin, BSA) has been established by UV-Vis, fluorescence and synchronous spectroscopic studies. The stability of complex 2B in the presence of GSH was evaluated. The complexes catalytically convert coenzyme NADH to NAD⁺via hydride transfer. Cp^xbiph complexes 2B and 4B induce cell apoptosis and arrest cell cycles at the S and G₂/M phases towards A549 cancer cells and increase the reactive oxygen species dramatically, which appear to contribute to the remarkable anticancer activity.

Group IV organometallic compounds based on dianionic "pincer" ligands: synthesis, characterization, and catalytic activity in intramolecular hydroamination reactions

Neutral Zr(IV) and Hf(IV) diamido complexes stabilized by unsymmetrical dianionic N,C,N' pincer ligands have been prepared through the simplest and convenient direct metal-induced Caryl-H bond activation. Simple ligand modification has contributed to highlight the non-innocent role played by the donor atom set in the control of the cyclometallation kinetics. The as-prepared bis-amido catalysts were found to be good candidates for the intramolecular hydroamination/cyclization of primary aminoalkenes. The ability of these compounds to promote such a catalytic transformation efficiently (by providing, in some cases, fast and complete substrate conversion at room temperature) constitutes a remarkable step forward toward catalytic systems that can operate at relatively low catalyst loading and under milder reaction conditions. Kinetic studies and substrate-scope investigations, in conjunction with preliminary DFT calculations on the real systems, were used to elucidate the effects of the substrate substitution on the catalyst performance and to support the most reliable mechanistic path operative in the hydroamination reaction.