The application of solid phase extraction in organic synthesis using fluorous derivatised metal catalysts

This thesis describes the synthesis, characterisation and coordination chemistry of a variety of fluorinated ß-diketonate ligands (I) and carboxylate ligands (II), the catalytic activity of the resultant metal complexes for oxidation and C-C bond forming reactions, and an evaluation of fluorous methodologies for catalyst/product separation. (Fig. 3706) Chapter 1 introduces the concept and application of fluorous methodologies, including fluorous biphase catalysis and fluorous reverse phase silica gel (FRPSG), as alternative approaches to product/catalyst separation in homogeneous catalysis. Chapter 2 describes the synthesis and characterisation, in some cases by X-ray diffraction, of the fluorinated ß-diketonate ligands and an evaluation of the influence of the perfluoroalkyl groups on the coordination of these ligands to a variety of transition metals including copper, nickel, palladium and zinc. Chapter 3 outlines attempts to sue fluorous nickel ß-diketonate complexes for the oxidation of sulfides. The results indicate that a metal catalyst is not necessary for oxidation in this system although the veracity of catalyst separation using FRPSG was established. This chapter also describes the investigation of a fluorous molybdenum ß-diketonate complex for the oxidation of alkenes, although the extreme moisture senstiviity of the complex negated any attempts at recovery and recycling. The scope of Lewis acid catalysed coupling of ß-diketones with cyanoformates and the ability to reuse and recycle the fluorinated ß-diketonate catalysts is described in chapter 4. Chapter 5 describes attempts to extend this efficient separation procedure to the C-C bond forming reactions of rhodium carboxylate dimers. Although catalysis was observed, catalyst/product separation using FRPSG was unsuccessful. Chapter 6 summarises all the experimental details and spectroscopic data, whilst a CD-rom includes all of the crystallographic data.