Some oxidation reactions utilizing hydrogen peroxide adducts in combination with carboxylic anhydrides
Interest grew in the development of new oxidising agents as a replacement for high purity meta-chloroperbenzoic acid (mCPBA) and avoiding the difficulty in obtaining high strength hydrogen peroxide. Magnesium monoperoxyphthalate (MMPP) has been advertised as a replacement. However due to problems of solubility of this oxidant in a number of solvents, it cannot be considered as a complete substitute for mCPBA. An oxidising agent is required to either complement MMPP, or succeed mCPBA entirely. This thesis describes the investigation of some hydrogen peroxide adducts as a possible contender to the extremely versatile oxidant, mCPBA. Urea-hydrogen peroxide adduct (UHP) in combination with either trifluoroacetic or acetic anhydride was used for the in situ formation of percarboxylic acids. Oxidations of various functional groups were carried out using these peracids. Reactions include: the epoxidation of terminal, electron deficient alkenes, such as octene, by trifluoroperacetic acid; the epoxidation of electron rich alkenes, such as styrenes and cyclohexenes, by peracetic acid; Baeyer-Villiger reactions of both aliphatic and alkyl aryl ketones by trifluoroperacetic acid; the conversion of anilines into nitrobenzenes; the oxidation of tertiary amines and sulphides; and the oxidative cleavage of dimethylhydrazones. A number of other hydrogen peroxide adducts were produced and their performance in various oxidation reactions was compared to that of ureahydrogen peroxide. Experiments in the formation of adducts to induce chirality in epoxidation reactions were also undertaken.