New manganese complexes with nitrogen donor ligands. Catalysts for oxidation reactions

摘要

The catalytic asymmetric oxidation of alkenes has special interest from both industrial and academic points of view. For this reason, catalysts able to perform these reactions in a faster and more effective manner have been developed along the latest years. This thesis describes the synthesis of new N-donor ligands (one bidentate, one bridging tetradentate and a family of spiro tetradentate), some of them chiral. The coordination of these ligands to different manganese salts is also described, giving mono-, bi- and pentanuclear complexes that have been fully characterized through structural, spectroscopic, electrochemical and magnetic techniques, using in some cases computational calculations. All complexes have been evaluated as catalysts for the epoxidation of aromatic and aliphatic alkenes. The effect of additives and ionic liquids in the catalytic media has also been studied, giving in general better results and allowing the catalyst reusability. Finally, the nature of some intermediate catalytic species was investigated.