Molecule and catalyst design for recognition and activation of small molecules
- Autores: Luis Javier Martínez Rodríguez
- Directores de la Tesis: Arjan W. Kleij (dir. tes.)
- Lectura: En la Universitat Rovira i Virgili ( España ) en 2016
- Idioma: inglés
- Tribunal Calificador de la Tesis: Elena Fernández Gutiérrez (presid.), Thomas Werner (secret.), Veronique Dufaud (voc.)
- Programa de doctorado: Programa de Doctorado en Ciencia y Tecnología Química por la Universidad Rovira i Virgili
- Materias:
- Enlaces
- Tesis en acceso abierto en: TDX
- Resumen
Small molecule activation opens up new opportunities for the valorisation of waste by-products generated on a large scale in industrial processes, which present an unsolved problem for the environment. Molecular design plays an important role to successfully trap, recognize and convert the substrates involved in these sustainable chemical transformations. Towards this end, different catalysts and receptors were synthetized, minimizing the cost-effectiveness and optimizing the efficiency under relatively mild conditions. The aim of the work described in this thesis is: (i) a full understanding of the self-assembly process behind supramolecular scaffolds, especially in calix[4]arenes. Study the influence of small changes in the cavitand core and in weak interactions which control the process of self-assembly. (ii) develop new methodologies for the synthesis of relevant organic syntons starting from abundant, cheap, industrial waste products. (iii) Extend the knowledge of classical chemical transformations with the aim to improve new catalyst and sensor design.
The first experimental chapter (Chapter 2) describes the synthesis of different families of cavitand complexes based on zinc-salphens for chiral recognition of small relevant molecules. The self-assembly process between the zinc-salphen units has been studied to encapsulate diamine substrates. Chapter 3 focusses on CO2 valorisation to obtain organic cyclic carbonates catalyzed by an organocatalyst based on the resorcin[4]arene motif. An important study of self-assembly was done, modifying the cavitand scaffold in order to minimize the competitive process which inhibits the catalytic activity. In Chapters 2 and 3, the cooperativity factors of the different cavitand families were considered to increase the efficiency of the processes. Chapter 4 presents a methodology to obtain 1,4 diols in a stereoselective fashion catalyzed by palladium. Starting from readily available vinyl cyclic carbonates and water as nucleophile, synthetically useful molecules can be produced from these CO2 derivatives without producing any by-products. The importance of ligand development and design in organometallic chemistry, especially in asymmetric catalysis, was studied in Chapters 2 and 4. Small molecule activation (CO2 and H2O) was performed in Chapters 3 and 4 to construct more valuable and complex syntons. Screening studies were performed to optimize both chemical protocols and the reaction scopes were investigated in order to find the limit of these methodologies.
