Chemistry of Aminoxides
Abstract
Amine oxides are multi-faceted compounds with numerous applications in synthetic organic chemistry. They serve as valuable targets or intermediates in multi-step syntheses, as protecting groups for aromatic amines, and as oxidants in transition metal catalyzed conversions. Apart from these laboratory applications, they are used on a large scale in industrial processes, as solvents for cellulose in derivatization-free fiber-making processes, and as non-ionic surfactants in detergents. Recent observations of novel reactions of amine oxides, such as autocatalytic decomposition processes and inducible degradations of amine oxides, have opened up a whole new area in amine oxide chemistry which will be exploited in this proposed project with regard to applications in synthesis and mechanistic insights. The novel procedures to be investigated are deoxygenative demethylations of N-methyl amine oxides and deoxygenations with oxygen transfer. Mechanism and kinetics of the two underlying pathways will be comprehensively studied. Deoxygenative demethylation of tertiary N-methyl amine oxides produces the corresponding secondary amines. This process will be developed into an effective and selective N-demethylation procedure and applied in alkaloid chemistry. The deoxygenation with oxygen transfer does not only effect a simple reduction of the amine oxides, but can be used to generate secondary oxidants in situ that are otherwise difficult to produce, such as hypochlorous acid and peroxynitrous acid in organic media. The former reagent will be employed for an efficient high-yield synthesis of important novel vitamin E derivatives, such as 5-formyl-g-tocopherol, 4-oxo-a-tocopherol, 4-hydroxy-a-tocopherol and the Simon II metabolite of vitamin E. The latter oxidant will allow for the first time to study the reaction between peroxynitrous acid and tocopherols in the absence of interfering reactions with reactive nitrogen oxide species that are typical of aqueous media. The outcome of the project is expected to considerably expand the knowledge on amine oxides and their reaction mechanisms. Direct results of the work will be an improved methodology based on the amine oxide reactions investigated, as well as novel synthetic procedures and their application in vitamin E chemistry.
keywords amine oxides secondary oxidants N-demethylation tocopherols hypochlorous acid
Publikationen
Instabilities in the System NMMO / Water / Cellulose (Lyocell Process) caused by Polonowski Type Reactions.
Autoren: Rosenau, T., Potthast, A., Hofinger, A., Sixta, H., Kosma, P. Jahr: 2002
Journal articles
Calixarenartige Makrocyclen durch Oxidation phenolischer Vitamin-E-Derivate.
Autoren: Rosenau, T; Potthast, A; Hofinger, A; Kosma, P Jahr: 2002
Journal articles
On a novel chromanone-naphthalenetrione rearrangement related to vitamin E.
Autoren: Rosenau, T; Potthast, A; Ebner, G; Hofinger, A; Kosma, P; Jahr: 2002
Journal articles
Radicals derived from N-methyl-morpholine-N-oxide (NMMO): structure, trapping, and recombination reactions.
Autoren: Rosenau, T., Potthast, A., Sixta, H. Kosma, P. Jahr: 2002
Journal articles
Cellulose solutions in N-methylmorpholine-N-oxide (NMMO) - Degradation processes and stabilizers.
Autoren: Rosenau, T., Potthast, A., Adorjan, I., Hofinger, A., Sixta, H., Firgo, H., Kosma, P. Jahr: 2002
Journal articles
Studies into reactions of N-methyl-morpholine-N-oxide (NMMO) and its hydrates with cyanuric chloride.
Autoren: Rosenau, T., Potthast, A., Kosma, P. Jahr: 2002
Journal articles
Synthesis and oxidation behavior of 2,4,5,7,8-pentamethyl-4H-1,3-benzodioxin-6-ol, a multifunctional oxatocopherol-type antioxidant.
Autoren: Rosenau, T; Potthast, A; Elder, T; Lange, T; Sixta, H; Kosma, P; Jahr: 2002
Journal articles
Stabilization and first direct spectroscopic evidence of the o-quinone methide derived from vitamin E.
Autoren: Rosenau, T; Potthast, A; Elder, T; Kosma, P; Jahr: 2002
Journal articles
Synthesis of novel 3-oxa-chromanol type antioxidants
Autoren: Adelwöhrer, R., Rosenau, T., Gille, L., Kosma, P. Jahr: 2003
Journal articles
Novel Tocopheryl Compounds XV. One-pot Formation of Furotocopheryl Derivatives.
Autoren: Adelwöhrer, C,; Rosenau, T.; Binder, W.H.; Kosma, P. Jahr: 2003
Journal articles
Novel Tocopheryl Compounds XVI. Nitration of alpha-Tocopheryl Acetate - a Mechanistic Study
Autoren: Adelwöhrer, C.; Rosenau, T.; Kosma, P. Jahr: 2003
Journal articles
Studies on the carbenium-iminium ions derived from N-methylmorpholine-N-oxide (NMMO)
Autoren: Rosenau, T., Potthast, A., Kosma, P. Jahr: 2004
Journal articles
A general, selective, high-yield N-demethylation procedure for tertiary amines by solid reagents in a convenient column chromatography-like setup.
Autoren: Rosenau, T; Hofinger, A; Potthast, A; Kosma, P; Jahr: 2004
Journal articles
3-Tocopherylisoxazolines by [2+3] cycloaddition
Autoren: Rosenau, T., Adelwöhrer, C., Hofinger, A., Mereiter K., Kosma, P. Jahr: 2004
Journal articles
Antioxidant properties of chromanols derived from vitamin E and ubiquinone.
Autoren: Gregor, W; Adelwöhrer, C; Rosenau, T; Grabner, G; Gille, L Jahr: 2004
Journal articles
Novel tocopherol compounds XX. 1,3,8-Trioxaphenanthrenes derived from g-tocopherol
Autoren: Adelwöhrer, C., Rosenau, T. Jahr: 2005
Journal articles
Untersuchungen zur Chemie von phenolischen Antioxidantien
Autoren: Adelwöhrer, C. Jahr: 2004
Doctoral Thesis
Project staff
Thomas Rosenau
Univ.Prof. Dipl.-Chem. Dr.rer.nat. DDr.h.c. Thomas Rosenau
thomas.rosenau@boku.ac.at
Tel: +43 1 47654-77411, 77471
Project Leader
01.05.2001 - 01.05.2004