This thesis describes the chemistry developed during a study of novel transition metalcatalysed reactions for the synthesis of carboxylic acid derivatives. Chapter 2 describes a novel protocol for the synthesis of primary amides from alcohols in one-pot where a metal complex mediates two fundamentally different catalytic processes. An iridium catalyst has been shown to be effective for the selective rearrangement of aldoximes into primary amides. In addition, an iridium-catalysed oxidation of activated alcohols via hydrogen transfer has been developed using an alkene as formal oxidant. These reactions have been combined in a sequential process affording good yields for a range of benzylic alcohols. An improved system for the rearrangement of aldoximes into amides using a new ruthenium catalyst is described in Chapter 3. Through a systematic program of optimisation excellent selectivity was achieved for a wide range of substrates at markedly reduced catalyst loading. Chapter 4 describes the development of a ruthenium-catalysed elimination reaction for the conversion of oxime ethers into nitriles. The application of this reaction to tandem and sequential reactions has been explored, albeit with limited success. Also, a method for the ruthenium-catalysed oxidation of alcohols using an electron-deficient alkene as hydrogen acceptor is described, and its application to a tandem oxidation process with a nitrogen nucleophile demonstrated. As an extension of the concept presented in Chapter 4, tandem oxidation processes with oxygen nucleophiles are the subject of Chapter 5. This strategy has been used for the oxidation of primary alcohols to their corresponding methyl esters in one-pot, with good yields obtained for a range of substrates. The use of water as a nucleophile in such a process has also been examined.

The alkoxytriphenylphosphonium ion intermediate of the Mitsunobu reaction for the esterification and inversion of configuration of an alcohol can be generated using the Hendrickson reagent, triphenylphosphonium anhydride trifluoromethanesulfonate, 27. While 27 was used in place of the Mitsunobu reagents (triphenylphosphine and a dialkyl azodicarboxylate) for the esterification of primary alcohols, the reaction failed with secondary alcohols such as (-)-menthol giving predominately elimination rather than the desired SN2 displacement. The difference between the two reactions was shown to be related to the more 'ionic' conditions generated when the Hendrickson reagent 27 was employed. An extreme sensitivity of the Mitsunobu reaction to the presence of salts was discussed and may indicate a mechanism involving ion pair clustering. Five-, six- and seven-membered cyclic analogues of the Hendrickson reagent 90-92 were prepared. A kinetic comparison of the cyclic analogues 90-92 revealed that a considerable increase in the rate of esterification could be achieved when the five-membered ring analogue 90 was used in a non-polar solvent such as toluene. Selected acyclic analogues of the Hendrickson reagent 27 possessing tributyl 118, tricyclohexyl 130 and diphenyl-2-pyridyl 137 functionalities were synthesised. However when 118, 130 and 137 were used for the attempted esterification of (-)-menthol, elimination was the major reaction pathway. Diphenyl-2-pyridylphosphonium anhydride triflate 137 was found to be a useful reagent for the synthesis of acyclic dialkyl ethers from primary alcohols. A polymeric version of the five-membered ring analogue 56, prepared by reaction of the polymer-supported 1,2-bis(diphenylphosphinyl)ethane 57 with triflic anhydride, was used for the preparation of simple esters and amides. A new dehydrating agent, polymer-supported triphenylphosphine ditriflate 157, was readily prepared from the oxidised form of commercially available polymer-supported triphenylphosphine and triflic anhydride. A wide range of dehydration-type reactions, such as ester, amide, anhydride, peptide, ether and nitrile formation, were performed in high yield using polymer-supported triphenylphosphine ditriflate 157. The reagent 157 was easily recovered and re-used several times without loss of efficiency. The use of 4-dimethylaminopyridine allowed the esterification of secondary alcohols with 157 to proceed without elimination and gave esters in high yield but with retention of configuration. Both reagents 56 and 157 provide an alternative to the Mitsunobu reaction, where the use of azodicarboxylates and chromatography to remove the phosphine oxide by-product can be avoided. However, the Mitsunobu reaction retains its supremacy for the inversion of configuration of a secondary alcohol. Preliminary investigations on the phosphityation of alcohols via the Hendrickson reagent 27, 1,3-benzodioxole formation using the Mitsunobu reaction and azodicarboxylate alternatives in the Mitsunobu reaction are described.

In this thesis the synthesis of vicinal stereocenters is investigated in two distinct contexts, namely the construction of 3,3-disubstituted oxindoles and the synthesis of b-hydroxy-a-amino acids. Both scaffolds are prevalent in a range of natural products and biologically relevant compounds and, therefore, methods for their synthesis are of great import. First, the construction of 3,3-disubstituted oxindoles using palladium-catalyzed domino reactions is described.  This covers two stereospecific methods for the construction of the desired oxindoles based on domino carbopalladation sequences.  The termination events for these domino reactions are carbonylation or cross-coupling.  In the carbopalladation-carbonylation reaction, we studied the possibilty of suppressing b-hydride elimination for substrates possessing pendant b-hydrogens.  In the carbopalladation-cross-coupling sequence, we examined the role of the boron source and substrate scaffold in the outcome of the reaction.  In both of these methods, an intricate balance of rates needs to be attained in order to achieve the desired domino sequences.  Thus, these investigations offer insight into the rates of the competing reactions, and the factors that influence these processes. Secondly, the stereoselective synthesis of b-hydroxy-a-amino acids is explored.  This has lead to two separate methods for the construction of this scaffold.  We first examined a 1,3-dipolar cycloaddition of azomethine ylides to aldehydes for the construction of syn-b-hydroxy-a-amino esters.  It was found that one set of azomethine ylides reacted through a 1,3-dipolar cycloaddition, while the other set reacted via a direct aldol reaction.  Finally, we studied an asymmetric transfer hydrogenation reaction to provide anti-b-hydroxy-a-amido esters from the corresponding a-amido-b-ketoesters.  Two protocols were developed for the reduction of these substrates, one using triethylammonium formate and the other using sodium formate in an emulsion.  The latter method gives high yields, diastereoselectivities and enantioselectivities for a broad range of substrates. / QC 20120605

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Nitroxide radical groups grafted on silica have been synthesized. The catalytic oxidation of alcohols to aldehydes and ketones using the nitroxide radical groups as a catalyst was also investigated. The results of scanning electron microscopy, infrared spectroscopy, and X-ray photoelectron spectroscopy confirmed that the nitroxide radical groups are successfully grafted onto silica. The yield of the catalytic oxidation using the catalysts is higher than 99%. The catalysts are easily recovered. Furthermore, the reused catalysts still keep high performance in the catalytic oxidation.

Thesis (Ph. D.)--Institute of Paper Chemistry, 1966. / Includes bibliographical references (p. 101-105).

Thesis (Ph. D.)--Institute of Paper Chemistry, 1974. / Includes bibliographical references (p. 129-130).

Aim of the work was to create the synthesis technology of “sandwich-type” CuO/γAl2O3, Co3O4/γAl2O3 and MnO2/γAl2O3 adsorbent-catalysts, determine their properties, and investigate their implementation in alcohols removal processes.

Submitted in fulfillment of the academic requirements for the Masters Degree in Technology: Chemistry, Durban University of Technology, 2008. / The thermodynamic properties of binary liquid mixtures involving ionic liquids (ILs) with alcohols were determined. ILs are an important class of solvents since they are being investigated as environmentally benign solvents, because of their negligible vapour pressure, and as potential replacement solvents for volatile organic compounds (VOCs) currently used in industries. Alcohols were chosen for this study because they have hydrogen bonding and their interaction with ILs will help in understanding the intermolecular interactions. Also, their thermodynamic properties are used for the development of specific chemical processes. The excess molar volumes of binary mixtures of {1-ethyl-3-methylimidazolium ethylsulfate + methanol or 1-propanol or 2-propanol}, {trioctylmethylammonium bis (trifluoromethyl-sulfonyl) imide + methanol or ethanol or 1-propanol}, {1-buty-3-methylimidazolium methylsulfate + methanol or ethanol or 1-propanol} were calculated from experimental density values, at T = (298.15, 303.15 and 313.15) K. The Redlich-Kister smoothing polynomial was fitted to the excess molar volume data. The partial molar volumes of the binary mixtures {1-ethyl-3-methylimidazolium ethylsulfate + methanol or 1-propanol or 2-propanol}, {trioctylmethylammonium bis (trifluoromethyl-sulfonyl) imide + methanol or ethanol or 1-propanol}, {1-buty-3-methylimidazolium methylsulfate + methanol or ethanol or 1-propanol} were calculated from the Redlich-Kister coefficients, at T = (298.15, 303.15 and 313.15) K. This information was used to better understand the intermolecular interactions with each solvent at infinite dilution. iii The isentropic compressibility of {trioctylmethylammonium bis (trifluoromethyl-sulfonyl) imide + methanol or ethanol or 1-propanol}, were calculated from the speed of sound data at T = 298.15 K.

The research described in this thesis focuses on the catalytic acylative kinetic resolution (KR) of aromatic secondary alcohols, using a planar-chiral 4-(dimethylamino)pyridine (DMAP) organocatalyst. In the first part of this thesis, the substrate scope of the above mentioned process was expanded to aromatic secondary alcohols that contain an extra functional group in the alkyl moiety, such as 1,2-azido alcohols, 2-hydroxy-2-aryl-ethylphosphonates and 2-hydroxy-2-aryl esters. Thus, the preparation of highly functionalized compounds in their enantiomerically pure form with excellent enantiomeric excess (up to 99% ee) was achieved. Furthermore, the synthetic applicability of this methodology was illustrated through the synthesis of two high value compounds, (R)-Pronethalol and (S)-3-hydroxy-N-methyl-3-phenylpropanamide, which is an immediate precursor of bioactive molecules such as (S)-Fluoxetine. The second part of this thesis deals with the mechanistic study of the acylative KR catalyzed by the planar-chiral DMAP derivative. Reaction Progress Kinetic Analysis methodology was used in the investigation of the reaction mechanism, probing that no notable product inhibition or decomposition of the catalyst occurs in the studied system. The reaction rate showed fractional order dependence on the concentration of both reactants. Furthermore, NMR spectroscopy was utilized to study the equilibrium between the different catalyst states, which explains the measured kinetics of the reaction.