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Decarboxylierende Kreuzkupplungen sind eine neue Synthesestrategie zur Darstellung von unsymmetrischen Biarylen oder Ketonen aus Kaliumcarboxylatsalzen und Arylhalogeniden. Im Vergleich zu traditionellen Kreuzkupplungsreaktionen (z.B. Suzuki-Miyaura-Reaktion) kann mit dieser Methode auf den Einsatz von stöchiometrischen Metallverbindungen verzichtet werden, was zu einer nachhaltigeren Synthese führt. In der vorliegenden Arbeit sind neue bimetallische Katalysatorgenerationen entwickelt worden, die die decarboxylierende Kreuzkupplung mit Arylsulfonaten (Aryltriflate u. -tosylate) ermöglicht. Durch die Kombination von Sulfonatkupplungspartnern und Mikrowellenstrahlung konnte die Anwendungsbreite der Reaktion erheblich vergrößert werden und die Reaktionszeit von Stunden auf wenige Minuten reduziert werden. Die Entwicklung eines neuen silberbasierten Katalysators erlaubt die Absenkung der Reaktionstemperatur auf 130 °C und eröffnet durch seine Reaktivität die Umsetzung neuer Benzoesäuren in der Kupplung. Ein neues vollständig lösliches Katalysatorsystem wurde entwickelt mit dem ein Durchflussverfahren für decarboxylierende Kreuzkupplungen gelungen ist.
The present PhD thesis is mainly focused on synthesis, characterization and catalytic application of functionalized triphenylphosphine (TPP) ligands and their complexes. We developed a simple and effective strategy to immobilize TPP: A methylester group attached to one of the phenyl rings of TPP allowes the derivatization of the ligand with 3-trimethoxysilylpropylamine, a typical silane coupling agent used for the covalent immobilization of organic compounds on silica surfaces. The resulting functionalized TPP was further coordinated to Pd, Rh and Ru precursors to achieve homogeneous complexes which can be tethered on silica by the post synthetic grafting method and co-condensation method. The obtained heterogeneous catalysts exhibited excellent activity, selectivity and reusability in Suzuki, hydrogenation and transfer hydrogenation reactions. In order to investigate the stability of the catalysts, different types of characterizations such as TEM, solid state NMR of the used catalysts as well as AAS of filtrate and leaching tests were carried out. The results prove the practicability and efficiency of our method. This strategy was further modified to generate an anionic side chain linked to the TPP core by simply replacing the trimethoxysilylpropylamine group by sodium(3-amino- 1-propanesulfonate), which allowes the immobilization on imidazolium modified SBA-15 through electrostatic interaction. The obtained material was further reacted with PdCl2(CNPh)2 and the resulting hybrid material was used for the hydrogenation of olefins allowing mild reaction conditions. The catalyst shows excellent activity, selectivity and stability and it can furthermore be reused for at least ten times without any loss of activity. TEM images of the used catalyst clearly show the absence of palladium nanoparticles, proving the high stability of the palladium compound. By AAS no palladium could be detected in the products and further leaching tests very- fied the reaction to be truly heterogeneous. This concept of non-covalent immobili- zation guarantees a tight bonding of the catalytically active species to the surface in combination with a high mobility, which should be favorable for other catalyses.