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The majority of this project is to discover novel mechanistic pathways for a wide range of organic reactions involving different carbonyl compounds with trivalent phosphorus compounds. The first part of our research involved the one-pot intra-molecular cyclisation reaction of the different 2-substituted benzoylphosphonates in the presence of triniethyl phosphite. The mechanistic pathway of these reactions was found to intra-molecular insert to the electrophilic carbonyl centre in the substituent via the initially formed carbanionic intermediate. The subsequently formed tricyclic phospholane intermediate [δp ~ -48 (d) & +18 (d), Jpp 33 Hz] were observed from the NMR spectra of the crude reaction prior the "formation of the final cyclic benzofuranyl-phosphonate products. Experiments were carried out ,to study the decomposition product of the observed phospholane intermediate in the absence of phosphite, which led to. the formation of the novel ~- ketophosphonates. We have also generated a senes of anionic intermediates in situ usmg different phosphate- phosphonates, and studied their anionic manors inter- and intra- molecularly toward the electrophilic carbonyl reacting sites. The second part of our project involved the reactions of various halogeno-substituted 2,5-cyclic- diones with different trivalent phosphorus compounds. Under the treatment of trialkyl phosphites, many of the, related non-halogenated substituted cyclic diones were report to process deoxygenations reaction followed .by dimerisations and .rearrangements reactions. , However, in Our practical, a range of unusual stabilised phosphonium ylides were isolated and their structures were studied analytically in. detail by the NMR data. In particular, .ylidic phosphinie oxide and ylidic bisphosphine oxide were successfully crystallised, which allowed us to study the physical properties of these ylides by the X-ray crystallography. The mechanistic pathways of these reactions proceeded differently, depending on the number of substituents on the cyclic diones.

The preparation of the following new cyclic, bicyclic and cage phosphinites are reported and characterised by a combination of NMR spectroscopy, mass spectrometry and elemental analysis. l-methoxyphosphinane (2.8), l-methoxyphospholane (2.10), 5-methoxy- dibenzo[b,d]phosphole (2.12), I-methoxy-2,2,3,4,4-pentamethylphosphetane (2.14) (which has been previously reported), a-PhobPOMe (2.17), 1-(-)-menthoxyphosphinane (2.21), a-PhobP(-)- menthol (2.22), s-PhobP( - )-menthol (2.23), (S)-2,2' -bis(phosphinan-l-yloxy)-I, 1 ' -binaphthyl (2.24), (S)-2,2'-bis(s-phob-l-yloxy)-I,1 '-binaphthyl (2.25), CgPOR, R= OMe (2.29), OEt (2.30), oiPr- (2.31), 4-C6~OMe (2.32), 4-C6~Me (2.33), 4-C6~CI (2.35), 4-C6~CF3 (2.36), and 4-C6~CF 3 (2.37), The methoxy based phosphinites were treated with solutions of H20 in MeOH, while the cage phosphinites and the previously prepared compounds CgPOR where R = C6H5 (2.30), 2-C6~Me (2.34), 2,4,6-C6H2Me3 (2.35), 2,4-C6H3tBu2 (2.36), CH2CF3 (3.1), and CH2CH(CF3)2 (3.2) were treated with H20 in aq HCI and MeCN. The resulting hydrolysis reactions were followed by 31p NMR spectroscopy and the times to 50% hydrolysis (t50) compared. In general, the stability to hydrolysis was found to increase with increasing steric bulk, electronegativity of the substituents and as the phosphacycle C-P-C angle approaches 90°. Hydrolysis of (2.8) was carried out with 170 labelled water, with the results supporting the mechanism proceeding via nucleophilic attack of H20 at phosphorus. This was used to explain the increased stability of phosphinites as C-P-C angle approaches 90° by consideration of the relative energies of the individual trigonal bipyramidal intermediates. The synthesis of the fluorophosphines, CgPF (4.1), a-PhobPF (4.2), s-PhobPF (4.3) and tBu2PF (4.5) was achieved. All are shown to be completely stable to disproportionation, while stability to hydrolysis increased in the order (4.1) » (4.3) > (4.2) » (4.5). DFT calculations of disproportionation reactions are presented. These suggested that destabilisation of TBP intermediates is caused by ring strain in the fluorophosphines (4.1)-(4.3). This increases the energy of TBP intermediates and thus increases the stability of the bicyclic and cage fluorophosphines towards disproportionation. The electronic and steric properties of all novel compounds has been assessed by formation of the corresponding selenides, platinum(II) and rhodium(I) coordination complexes and comparison of the chemical shifts, coupling constants and carbonyl stretching frequencies. X- ray crystal structures for [PtCI2L2] where L = (2.8), (2.10), (2.12), (2.17), (2.29), (4.2) and (4.3), the oxides of (2.29), (2.30) and (2.31) and the free phosphinites (2.34), (2.39) and (2.40) are also reported. Rhodium complexes of the methoxyphosphinites and cage phosphinites and all fluorophosphines were tested as catalysts in the hydroformylation of l-hexene and/or l-heptene. The fluorophosphines were the most successful catalysts with (4.1) significantly outperforming PPh3. Variation of the amount of (2.35) used allowed the selective formation of either n- or iso- aldehyde. One equivalent of (2.35) led to a n:iso ratio of 1.3 while ten equivalents of (2.35) gave a n:iso ratio of 0.3. Due to the success of the fluorophosphines, their nickel complexes were also tested as catalysts in the hydrocyanation of 3-pentenenitrile. This was the first time that a fluorophosphine has been applied in catalysis and again (4.1) outperformed the other ligands, achieving comparable selectivities and activities to the commercially used P(O- Tolj; Finally the rhodium complexes of chiral phosphinites (2.21)-(2.25) were applied in asymmetric hydrogenation, although high conversions were obtained selectivities were low.

Organophosphorous compounds and their use as reagents have witnessed significant interest from researchers in recent years. This can be attributed to their vast array of applications industrially and synthetically. Phosphorodiamidites and their derivatives are of particular interest especially in relation to oligonucleotide synthesis. Additionally, they have been utilised as precursors to phosphonamidates which can be used as intermediates towards pyrophosphate analogues such as bisphosphonates. Unfortunately, the synthesis of phosphorodiamidites and their analogues, particularly on a large scale is hampered by their high instability to air and moisture as well as the instability of their synthetic precursor, phosphorus trichloride (PCh). The continued use of large quantities of organic solvents as liquid media for chemical reactions, coupled with high temperatures and pressures is a major concern in today's chemical industry. Ionic liquids are low volatility solvents which are being increasingly used as popular alternatives to molecular solvents. Ionic liquids based on the bis[trifluoromethyl)sulfonyl] imide (NTf2r anion provided a suitable environment for the novel one-pot synthesis of a series phosphorodiamidite and phosphoramidite reagents. In addition to providing a stable environment for the synthesis, the ionic liquids could be utilised as storage media for these reactive materials.

Includes bibliographical references. / 2 v. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Studies the preparation and characterisation of oxygen, sulfur and selenium derivatives of diorganophosphinothioformamides and their coordination to metal centres. / Thesis (Ph.D.)--University of Adelaide, Dept. of Chemistry, 1995

This thesis details the syntheses of catalysts and their applications in asymmetric reactions. Initially, the project focused on phase transfer catalysts; quaternary phosphonium salts derived from diethyl tartrate or from commercially available phosphorus compounds and their use primarily in the alkylation of N,N-diphenyl methylene glycine tert-butyl ester. Although some of the salts showed the ability to catalyse the alkylation reaction, all products obtained were racemic. The project then focused on bifunctional organocatalysis; catalysts derived from isoquinoline and BINOL were studied in Michael addition reactions between ethyl nitropropionate and MVK. Possible evidence for a bifunctional effect was observed, however, all Michael addition products obtained were racemic. Finally, an examination of proline-derived diamines as catalysts for aldol reactions is reported. Reversing the positions of the acid and base moieties of the catalyst results in the formation of the opposite enantiomer of the aldol product. In addition, these proline-derived diamines, along with two catalysts derived from a biarylazepine, were tested in a series of asymmetric reactions, with the best enantioselectivities (up to 90% ee) obtained in the conjugate addition between enones and nitro-containing compounds.

Les matériaux moléculaires vitrifiables présentent généralement des mobilités complexes incluant plusieurs relaxations non-exponentielles (non - Debye) comme le montre la spectroscopie de relaxation diélectrique. Une relaxation de type Debye est cependant observée dans plusieurs alcools primaires et amides et se caractérise par une contribution basse fréquence de très grande amplitude et de forme symétrique. Celle-ci demeure encore très mal comprise car elle correspond à environ 90% de la réponse diélectrique et ne semble pourtant pas couplé à la viscosité η(ω) ou la chaleur spécifique complexe C(ω). Ce type de relaxation Debye très particulière a été récemment identifié dans plusieurs composés pharmaceutiques de la famille des profènes.Au moyen de simulations de dynamique moléculaire, nous avons mené des investigations des propriétés physiques de trois composés moléculaires de la famille des profènes (ibuprofène, flurbiprofène et kétoprofène) dans l’état liquide afin d’analyser leurs organisations, leurs mobilités moléculaires et clarifier l’origine de la relaxation Debye. Nous avons montré que le processus Debye observé expérimentalement provient de mouvements extrêment lents des groupes carboxyliques très polaires dans des environnements moléculaires relaxant rapidement : une conversion interne des groupes O=C-O-H entre deux conformations d’équilibre couplée aux transformations du réseau de liaisons hydrogènes intermoléculaires. L’organisation dominante dans le liquide se trouve être composée de petits agrégats correspondant à des associations en dimères cycliques précurseurs de l’ordre cristallin. L’influence d’une situation de confinement sur les mobilités moléculaires a aussi été explorée en lien avec des études récentes de spectroscopie diélectrique. / Molecular glass-formers usually exhibit complex mobility including multiple non-simple exponential (non-Debye) relaxation processes as observed from dielectric relaxation spectroscopy. However, a Debye relaxation type is observed in several primary alcohols and amides, and is characterized by a low frequency contribution of very large amplitude and symmetrical shape. It is still very poorly understood because it is about 90% of the dielectric response and seems not yet coupled to the viscosity η (ω) or the complex specific heat C (ω). This very peculiar Debye relaxation has been recently identified in several pharmaceutical compounds of the profens family. By means of molecular dynamics simulations, we have conducted an investigation of physical properties of the three molecular compounds of the profens family (ibuprofen, flurbiprofen and ketoprofen) in the liquid state in order to analyze their organizations, their molecular mobilities and to clarify the origin of the Debye relaxation. We have shown that the Debye process observed experimentally originates extremely slow movements of very polar carboxyl groups in the molecular environments with rapidly relaxing: an internal conversion of the O=C-O-H groups between two conformations of equilibrium coupled to changes of the network of intermolecular hydrogen bonding. The dominant organization in the liquid is found to be composed of small hydrogen bonding aggregates corresponding to associations in cyclic dimers precursors of the crystalline order. The influence of a situation of confinement on molecular mobility has also been explored in relation with of the recent studies of dielectric spectroscopy.