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Item Planar chiral oxazolines based on [2.2]paracyclophane : a new toolbox for asymmetric synthesis : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Chemistry at Massey University, Manawatū, New Zealand(Massey University, 2024-03-07) Tewari, ShashankThis thesis contains total 7 chapters, dealing with the synthesis of planar chiral Oxazolines based on [2.2]paracyclophane, enantiopure products obtained from their resolution, synthesis of metal-based chiral complexes, studies on C-H activation field, namely selective remote β-C-H activation of cyclic amines, and future ideas towards the goal. As the main focus of this thesis is on the development of novel planar chiral [2.2]paracyclophane derivatives, Chapter 1 starts with a brief description of [2.2]paracyclophane chemistry. A short introduction about the synthesis of key enantioenriched [2.2]paracyclophane derivatives is given. Finally, a short introduction of the recent applications of [2.2]paracyclophane-based ligands in asymmetric catalysis is also mentioned. Chapter 2 outlines a brief overview of the role of 2-oxazolines. 2-Oxazolines have been utilized in the field of asymmetric catalysis as ligands and chiral auxiliaries. The chapter briefly discusses the synthesis and highlights some of the uses of 2-oxazolines as chiral ligands. Chapter 3 describes the concise synthesis of planar chiral oxazolines based on [2.2]paracyclophanes. Various oxazoline-based compounds that were synthesized are all discussed in Chapter 3. The synthesis of mono-oxazolines coupled to [2.2]paracyclophanes, based on the methodology developed in our lab was accomplished. The next were the synthesis of bis-oxazolines and tetra-oxazolines coupled to [2.2]paracyclophane. The chapter mentions all the details and substrate scope generated with oxazolines. Chapter 4 focuses on the resolution of [2.2]paracycoplane by the hydrolysis of the oxazolines. The enantiopure products like planar chiral mono-acids, bis-acids, and partial acids were obtained by hydrolysis of the oxazolines. Apart from them, a section in the chapter describes the decarboxylative phosphorylation that was achieved through our planar chiral acids. Synthesis of planar chiral diamines via Curtius rearrangement of the diacids is also described in the chapter, followed by phanol synthesis. A part of the above chapter describes about the rhodium paddle-wheel complex formed by partial chiral acids. An attempt to make dinuclear gold complexes was made that was also successful. Overall, chapter four is the highlight of the thesis, where a lot of pure chiral products are made and their utility is explained in the field of asymmetric catalysis. Chapter 5 describes the remote β-C-H activation of cyclic amines. Attempts were made to accomplish the functionalization through the directing group strategy. The directing groups based on heterocyclic piperidine and cyclic amines were synthesized successfully. These pre-made directing groups were used for the C-H bond functionalization but the functionalization possessed many challenges that made the functionalization difficult. Chapter 6 explains the future scope of the research work mentioned in this thesis. Finally, Chapter 7 describes the experimental procedures and characterization of the synthesized compounds mentioned in Chapters 3 to 5.Item Synthetic studies towards dictyoxetane and the dolabellanes : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Chemistry, Massey University, New Zealand(Massey University, 1997) MacKenzie, Karla RuthDictyoxetane (1) has been isolated from Dictyota dichotoma, a brown alga found in the Indian Ocean. It has an unusual pentacyclic structure which has not yet been synthesised. It is a diterpene which is closely related to the dolabellanes, an important class of bioactive compounds. A stereoselective synthesis of the linearly fused cyclohept[f]indene system is described. Selective epoxidation of cycle-octadiene (142), followed by hydrolysis to the diol (143) and oxidative cleavage allowed preparation of the dialdehyde (141) on large scale. Treatment of this with potassium carbonate causes an intramolecular aldol reaction to form cycloheptadiene- carboxaldehyde (140). An E- selective Wittig reaction is performed with 4- carboxybutyl-triphenylphosphium bromide, to produce the acid (139). This is subsequently converted to the vinyl ketone (138) followed by an intramolecular Diels Alder reaction to produce the desired cyclohept[f]indene (137a). Utilisation of a Z- selective Wittig reaction produced methyl ester (145z). Conversion to cyclohept[f]indene occurred via an intramolecular Diels-Alder of the subsequent vinyl ketone (138z). Conversion of acid (139) to the methyl ester (145) followed by an intermolecular Diels Alder gave the endo- product. Subsequent attempts to cyclise this to the cyclohept[f]indene via an intramolecular Claisen reaction to give the third isomer were unsuccessful. Cyclohept[f]indene is the backbone for dictyoxetane and can be efficiently synthesised in eight steps from 1,5-cyclo-octadiene (142) in a diastereoselective synthesis. This route allows for further modification of functionality to the linearly fused ring system and paves the way for further synthetic studies towards the dolabellanes.Item Single palladium sites supported on carbon capsules : synthesis, structure, and catalysis : a thesis presented in partial fulfilment of the requirements of the degree of Masters of Science in Chemistry at Massey University, Manawatu, New Zealand(Massey University, 2019) Olive, Nicholas; Symon, NicholasThis work investigates the impregnation of palladium into hollow carbon capsules through a novel synthesis method. This work investigates the feasibility of the method, improves on the method and suggests further improvements. The formation of palladium nanoparticles in hollow carbon capsules is investigated by varying the loading of palladium. This is further investigated by demonstrating the effect of other synthesis variables. The synthesized single palladium sites supported on hollow carbon capsules are then investigated for catalytic activity. These catalysts were found to be catalytically active for the Suzuki coupling reaction.Item Synthetic studies towards panacene : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Chemistry at Massey University(Massey University, 1987) Gibson, Jennifer JoySYNTHETIC STUDIES TOWARDS PANACENE (1) 2-Trimethylsilyloxyfuran (l}) and 2-acetyl-1 ,4-benzoquinone (6) were prepared according to published methods. The uncatalysed addition of 2-trfmethylsilyloxyfuran (23) to the quinone (6) gave cis-3a,8b-dihydro-8-acetyl-7-hydroxyfuro [3,2-b]benzofuran-2-(3H)-one (24) in 50% yield. The reaction of other 1,4-benzoquinones was investigated, establishing the necessity of an activating substituent at C-2 of the quinone. Attempts to reduce the acetyl group of cis-3a,8b-dihydro-8- -acetyl-7-hydroxyfuro[3,2-b]benzofuran-2-(3H)-one (24) to the ethyl group present in Panacene (l) were unsuccessful, although reduction of the ketone with sodium borohydride gave cis-3a,8b-dihydro-8-(1 '-hydroxyethyl)-7-hydroxyfuro[3,2-b] benzofuran-2-(3H)-one (51). The conversion of cis-3a,8b-dihydro-8-acetyl-7-hydroxyfuro [3,2-b]henzofuran-2-(3H)-one (24) to cis-3,3a,9b-trihydro- 5-hydroxy-5-methylfuro[3,2-c][2]benzopyran-2,6,9-(5H)-trione (58) was carried out using cerie ammonium nitrate.Item Multicomponent metal-organic frameworks : a thesis presented in partial fulfilment of the requirements of the degree of Doctor of Philosophy in Chemistry at Massey University, Manawatu, New Zealand(Massey University, 2015) Liu, LujiaIntroducing multiple functional groups into the pores of metal-organic frameworks (MOFs) promise sophisticated properties. Precise control over the position of these functional groups would enable the 3D chemical environment of discrete void spaces to be tailored. This was an outstanding challenge prior to this work. In this thesis we present a study of the synthesis, characterization and properties of MOFs that can meet this goal. These MOFs are multicomponent in nature, being built up from three geometrically distinct organic ligands. Functional groups can be appended to these ligands and are incorporated in precise locations and with perfect order in the frameworks. The chemical environment of the pores of these MOFs is “programmed” by these functional groups. MOFs constructed in this way give rise to exceptional gas adsorption characteristics, unexpected stability towards water vapour, and tunable catalytic properties.Item Porphyrins for surface modification : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Chemistry at Massey University, Palmerston North, New Zealand(Massey University, 2001) Campbell, Wayne MasonThe controlled synthesis of a variety of benzoic acid porphyrins ranging from monomers to arrays for the modification of TiO2 and GaAs semiconductors, and sulfur functionalised porphyrin monomers for attachment to GaAs and Au surfaces was achieved. A semi-quantitative study of the photosensitisation of TiO2 by the porphyrin acids was carried out. The syntheses of β-styryl linked porphyrin benzoic acids and some meso-substituted benzoic acid porphyrins was successfully carried out employing Wittig chemistry and classical porphyrin-forming condensation reactions with appropriate formyl methyl esters. Hydrolysis of the resulting porphyrin esters provided a facile and reliable acid synthesis, particularly where multi-step reactions were necessary. It was also demonstrated that acid functionality on porphyrins could be generated from aldehydes via esters, even though direct oxidation of the aldehydes to acids could not be achieved. The syntheses of "dipole" and "collinear" diporphyrins were achieved, providing two different porphyrin light harvesting arrays for evaluation on semiconductor surfaces. As a result of the synthesis of a new linear diporphyrin Building Block C, an alternative pathway to the controlled syntheses of mixed-metal and mixed-porphyrin arrays was achieved. This provided an alternative strategy for the controlled placement of three different metals into three different porphyrins of a linear triporphyrin, pentaporphyrin and a larger star-shaped nonaporphyrin. The exploitation of the stepwise controlled synthesis of the triporphyrin systems was expanded to include mixed-porphyrin systems synthesised with a unique tetraester porphyrin phosphonium salt. This phosphonium salt afforded mixed-diporphyrin and mixed-triporphyrin arrays, which were hydrolysed to give "sticky" mixed-diporphyrin and triporphyrin acid arrays. An alternative milder and higher yielding stepwise Wittig method was developed for the synthesis of a star shaped TXP pentaporphyrin. This new method involving milder base conditions gives advantages over the traditional acid catalysed approach developed in these laboratories. It is now possible to build these arrays in a stepwise manner with acid labile metals present in the porphyrin moieties. Access to the controlled synthesis of "sticky" mixed-pentaporphyrin arrays was then achieved using this new methodology. With the synthesis of a variety of unique benzoic acid functionalised porphyrin monomers and multiporphyrin array systems, evaluation of their performance in the dye-sensitised TiO2 Grätzel cell was carried out. The development of a reliable solar cell testing apparatus and procedures required to assess the solar cell performance of these chromophores is presented. None of the conditions employed have been optimised, but insights into the significance of the porphyrin photoelectrochemical cell variables has been obtained. It was determined that the porphyrin acids are better photosensitisers than their salts, and that Zn(II) metalloporphyrins performed best as dyes. The results also suggest that Cu(II) metalloporphyrins are worth pursuing in future where long term stability of the chromophores is required in solar cells. It was also found that adsorption solvent choice, electrolyte composition and dye concentrations are all critical to cell performance, and should all be optimised in future studies. The tetraaryl β-substituted monoporphyrin acids were found to have a significant advantage over the multiporphyrin arrays and other monoporphyrins synthesised and examined in this work. A variety of new disulfide porphyrins and some new 2- and 3-thienylporphyrins were successfully synthesised. A new class of terthiophene-appended porphyrins was also synthesised. Using a combination of Wittig chemistry and classical condensation reactions, β-substituted, and bis- and tetra-meso-porphyrin variants were synthesised and characterised. Both the bis- and tetraterthienylpoprhyrins were isolated as mixtures of atropisomers.Item Synthesis and characterisation of biomaterials for use as markers of health and disease : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Chemistry at Massey University(Massey University, 2001) Desai, Rakesh NatverlalThe bicyclic[4.3.0]nonane ring system is commonly found in many complex bioactive natural products, such as spongians and several novel steroids. Previous examples of ester tethered cycloaddition reactions were limited to activated dienes and dienophiles. The synthesis of a range of precursors, in which an unactivated diene and dienophile were linked via an ester tether is described. Model studies into the synthesis of monocyclic and bicyclic lactones as possible pre requisites for the formation of the C/D rings of the spongian skeleton utilising intramolecular Diels-Alder reaction (IMDA) or alternative cyclisation methods such as free radical catalysed and Heck reaction were carried out with these substrates. However it was discovered that when the carbonyl group of the ester tether was in conjugation with the diene it caused a formidable challenge as none of the applied methods were found to be suitable for the cyclisation reactions. Chapters two to five were focused on attempts to synthesise glucuronides of phytoestrogen metabolites (isoflavones and isoflavans) glucuronide due to their potential interest as anti cancer agents. Also the steroidal hormone estrone glucuronide (for fertility testing) and testosterone glucuronide (for use in clinical laboratories and for drug testing) for the purpose of developing multipurpose home monitor by adapting the platform technology previously developed and used in a point-of-care monitoring device known as the Ovarian Monitor. The synthesis of phytoestrogen glucuronide is a relatively new concept and the literature revealed no successful chemical method to date. The desired phytoestrogen isoflavones required for stereoselective glucuronidation were successfully prepared from precursor deoxybenzoins using a new convenient and facile route. Reduction of the isoflavones to isoflavans was also carried out using standard literature procedures. Various activated and deactivated phenols (including a sterically hindered phenol) were successfully glucuronidated using various synthetic routes as model studies. The information garnered from the model studies was utilised for the glycosylation of isoflavones and isoflavan but numerous attempts to obtained the glucuronides by using direct methods failed. Even more reactive glycosyl donors such as the sulfoxide sugar and acetimidate sugar also failed to effect glycosylation of these phytoestrogen metabolites. The relative insolubility and instability of the chromene ring under acid-base reaction conditions were compounding problems for the isoflavones. A new alternative route involving synthesis of the O-glucuronides by the prior synthesis of the glycosides, hydrolysis to the glucosides and then TEMPO mediated selective oxidation of the primary alcohol was successful for simple phenol, sterically hindered phenol and the steroids estrone and testosterone. However, this alternative route also failed to effect glucuronidation of the isoflavones. Attention was thus focused on the synthesis of isoflavone glucuronides using UDP-glucuronyl transferase. Towards this end (±) methoxy equol glucuronide has been synthesised enzymatically, and purified using chromatographic methods. The attempted enzymatic synthesis of formononetin gave instead the cleavage product 2-hydroxy, 4'-methoxy deoxybenzoin glucuronide. The glucuronides were fully characterised by 1H-1H 2D-COSY, 1H-13C 2D-HETCOR and DEPT spectra and the results unambiguously showed the β-linkage of the glucuronide ring with the aglycon moieties. The presence of the glucuronide ring at the C-4 position in 2-hydroxy, 4'-methoxy deoxybenzoin glucuronide was also confirmed by a long range coupling experiment(HMBC). The stereochemical integrity of the estrone glucuronide (E1G) obtained using perester coupling, acetimidate coupling and TEMPO catalysed oxidation methods were clinically tested by comparison with a standard curve obtained with a sample produced by the Koenigs-Knorr method. Testosterone glucuronide was studied for use as a biomarker to validate the concept of a multi-purpose home monitor for a variety of analyte glucuronides of clinical interest. Testosterone glucuronide antibodies with high affinity were generated by immunisation of sheep and testosterone glucuronide-HEW lysozymes conjugates were prepared. The standard curve for TG clearly showed it can be used for measurement of urinary TG at physiological concentrations. This methodology can be extended for analyte glucuronides of interest and can be used for development of biomarkers for health and disease. Thus a multi-purpose home monitor is now a reality and exciting commercial and practical applications are expected in the future.