| Popis: |
In this thesis three examples of transition metal catalyzed syntheses in non conventional reaction media are discussed. In particular, the research carried out has focused on: 1) The Pd-catalyzed oxidative carbonylation of primary amines in supercritical carbon dioxide to yield symmetrically N,N’-disubstituted ureas; 2) The Cr(salen)X catalyzed copolymerization of epoxides and carbon dioxide to yield polycarbonates. In this process carbon dioxide acts as both solvent and comonomer. 3) The synthesis and reactions of heptadienoic acids and derivatives in aqueous or biphasic systems. Two different approaches to this reaction are presented and discussed with regard to regio- and chemoselectivity of the process. A further investigation is devoted to the subsequent reactivity of the products obtained. An introduction is provided with the aim of underlining the importance of the combination of catalysis and non conventional media on the way to a more environmentally sustainable chemistry. Some recent examples of research carried out in this field are reviewed. |
