Hydrogen-transfer catalysis with Cp*Ir^III complexes:The influence of the ancillary ligands

Fourteen Cp*IrIII complexes, bearing various combinations of N- and C-spectator ligands, are assayed in hydrogen-transfer catalysis from isopropyl alcohol to acetophenone under various conditions to investigate ligand effects in this widely used reaction. The new cationic complexes bearing monodentate pyridine and N-heterocyclic carbene (NHC) ligands were characterized crystallographically and by variable-temperature nuclear magnetic resonance (VT-NMR). Control experiments and mercury poisoning tests showed that iridium(0) nanoparticles, although active in the reaction, are not responsible for the high activity observed for the most active precatalyst [Cp*Ir(IMe) 2Cl]BF4 (6). For efficient catalysis, it was found necessary to have both NHCs in monodentate form; tying them together in a bis-NHC chelate ligand gave greatly reduced activity. The kinetics of the base-assisted reaction showed induction periods as well as deactivation processes, and H/D scrambling experiments cast some doubt on the classical monohydride mechanism. © 2013 American Chemical Society

Potassium formate as a small molecule switch: controlling oxidation-reduction behaviour in a two-step sequence

Contains fulltext : 111394.pdf (preprint version ) (Open Access

La quimioembolización en el tratamiento del hepatocarcinoma

Presentamos una serie de 46 pacientes, a los cuales se les aplicó quimioterapia intraarterial con lipiodol y adriamicina, 27 de ellos con embolización arterial mediante partículas de fibrina, dentro de un tratamiento pluridisciplinario del hepatocarcinoma (HCC). Cinco pacientes posteriormente fueron resecados y a 13 se les practicó un trasplante de hígado ortotópico (THO). El objetivo de este trabajo es analizar la supervivencia y el grado de necrosis tumoral