Prof Joseph Michael
Position: Emeritus Professor of Organic Chemistry
Qualifications: BSc Hons, PhD (Witwatersrand), FRSSAf, FRSC, FSACI
Phone: 011 717 6753
The organic chemistry group at the University of the Witwatersrand operates as a team of seven academic staff members, each of whom heads a thrust devoted to different aspects of organic synthesis. Professor Michael's current research interests centre on the exploration of generalised synthetic strategies based on the versatile reactivity of enaminones of various types, including vinylogous amides, urethanes, cyanamides, nitramines and sulfonamides. These intermediates lend themselves to the synthesis of nitrogen heterocycles, especially alkaloids. Recent and current targets embrace such structurally diverse classes of alkaloids as indolizidine and quinolizidine alkaloids (e.g., frog skin neurotoxins, trail pheromones from ants, polyhydroxylated alkaloids with immunomodulatory and anticancer properties), perhydroindoles (e.g. Sceletium and Amaryllidaceae alkaloids), microbial metabolites (e.g., mitomycins and mitosenes, which have antibacterial and antineoplastic properties), and marine metabolites (e.g., lamellarins) . The synthesis of polycyclic analogues of the quinolone antibacterial agents is also under investigation. Control of relative and absolute stereochemistry is an important feature of this research, as are synthetic applications involving main and transition group elements (e.g. silicon, sulfur, palladium). A secondary interest, in collaboration with colleagues in the Structural Chemistry team, entails the synthesis of crystalline polymorphic compounds displaying a variety of hydrogen-bonded motifs.
Simple indolizidine and quinolizidine alkaloids. J. P. Michael, in The Alkaloids, Chemistry and Biology (H.-J. Knölker, ed.), Academic Press, London, Volume 75, in press.
Polymorphs of N-[2-(hydroxymethyl)phenyl]benzamide: structural characterization and analysis of molecule···molecule interactions by means of atom-atom potentials and DFT, C. F. Zipp, M. A. Fernandes, H. M. Marques, J. P. Michael and C. B. Perry, Crystal Growth and Design, 2011, 11, 1431–1436
Extensive hydrogen and halogen bonding, and absence of intramolecular hydrogen bonding between alcohol and nitro groups, in a series of endo-nitronorbornanol compounds, A. Lemmerer and J. P. Michael, Acta Crystallographica, Section C, 2011, C67, o288–o293.
Formal synthesis of (5R,8R,8aS)-indolizidine 209I via enaminones incorporating Weinreb amides, C. B. de Koning, J. P. Michael and D. L. Riley, Heterocycles, 2009¸ 79, 935–953.
Analogues of amphibian alkaloids: total synthesis of (5R,8S,8aS)-(–)-8-methyl-5-pentyloctahydroindolizine and [(1S,4R,9aS)-(–)-4-pentyloctahydro-2H-quinolizin-1-yl]methanol, C. Accone, C. B. de Koning, J. P. Michael and C. W. van der Westhuyzen, Beilstein Journal of Organic Chemistry, 2008, 4:5.
Hydrogen bonding patterns in a series of 1-arylcycloalkanecarboxamides. A. Lemmerer and J. P. Michael, CrystEngComm, 2008, 10, 95-102.
Indolizidine and quinolizidine alkaloids. J. P. Michael, Natural Product Reports, 2008, 25 , 139-165.
Quinoline, quinazoline and acridone alkaloids. J. P. Michael, Natural Product Reports, 2008, 25, 166-187.
Formal asymmetric synthesis of a 7-methoxyaziridinomitosene. J. P. Michael, C. B. de Koning, T. T. Mudzunga and R. L. Petersen, Synlett , 2006, 3284-3288.
A versatile synthesis of (±)-deoxyfebrifugine, an antimalarial alkaloid analogue, and related compounds, J. P. Michael, C. B. de Koning and D. P. Pienaar, Synlett, 2006, 383-386.
Studies towards the enantioselective synthesis of 5,6,8-trisubstituted amphibian indolizidine alkaloids via enaminone intermediates, J. P. Michael, C. B. de Koning and C. W. van der Westhuyzen, Organic and Biomolecular Chemistry, 2005, 3, 836-847.
Enaminones: versatile intermediates for natural product synthesis. J. P. Michael, C. B. de Koning, D. Gravestock, G. D. Hosken, A. S. Howard, C. M. Jungmann, R. W. M. Krause, A. S. Parsons, S. C. Pelly and T. V. Stanbury, Pure and Applied Chemistry, 1999, 71, 979-988 (general overview of our enaminone investigations).