Supramolecular Chemistry - Natural Product Synthesis - Reactive Intermediates
Supramolecular principles in nature : Comparison of natural and synthetic architectures; ATP Synthase - a machine on the nanometer scale; rhodopsin - a supramolecular photonic device.
Host-Guest Chemistry: Synthesis of macrocycles; supramolecular host design, cyclophanes, the central class of synthetic receptors: crown ethers, cryptands, calixarenes,cyclodextrines.
Molecular recognition - weak, noncovalent interactions: hydrogen bonding, dipole interactions, van der Waals forces, cation–π –interactions, π–π–stacking, charge transfer interaction, C–H–π –interaction, hydrophobic effects. Determination of binding constants, NMR-titration, binding of cations and anions.
Application of Host-Guest-complexes: phase transfer catalysis, sensors, molecular switches, ions channels, enzyme mimics, self replication of molecules.
Building principles of complex structures - Nanochemistry: Molecular capsules, squares, boxes, racks, ladders, grids, crystal engineering.
Molecular machines based on rotaxanes and catenanes: Synthesis of mechanically interlocked materials, principles of molecular machines, driving forces for molecular machines, molecular approaches towards molecular machines.
Order in liquids : Surfactants, liquid crystals.
J. W. Stee: "Supramolecular Chemistry" John Wiley, 2000.
J. F. Stoddart (ed.): "Monographs in Supramolecular Chemistry", Royal
Society of Chemistry.
F. Vögtle: "Supramolekulare Chemie", Teubner Studienbücher 1992.
J-M. Lehn: "Supramolecular Chemistry" VCH, 1995.
Natural Product Synthesis
Aims and historic development of total synthesis of natural products.
Retrosynthesis: Principles and tools of retrosynthesis.
Total synthesis of natural products: Advanced examples of total syntheses from different classes of natural products. Classical as well as actual examples are included, such as epothilones, endiine-antibiotics, diazonamide A, strychnine, tautomycin, fluvirucin, capnellen. Selection changes according to latest developments.
Synthetic methods applied in total synthesis: Methods used in the examples of total synthesis are covered from a more general view. Peptide synthesis, carbometallations, ring closing metathesis, lactonisation methods, protective group application, oligosaccharide synthesis, Mitsunobu reaction, Bergman cyclisation, asymmetric syntheses.
At the end of the course a natural product of advanced complexity reported in the actual literature is assigned to each student as a synthetic target. Students develop a proposal for the synthesis of this natural product and present this proposal in a seminar.
J. C. Nicolaou, E.. J. Sorense: "Classics in Total
Synthsis", VCH, 1995.
J. A. Gewert, J. Görlitzer et al: "Problems", Wiley-VCH, 1998.
K. C. Nicolaou et al. Angew. Chem. 2000, 112, 47.
E. J. Corey, X-M. Cheng. "The Logic of Chemical Synthesis", Wiley,
1989.
Actual publications from organic chemical journals.
Reactive Intermediates
Reactive Intermediates: Definition, Techniques of detection and identification of intermediates, scope and limitations of detection methods.
Radicals: Generation, reactivity, detection with ESR-spectroscopy, trapping reactions, spin trap reagents, consecutive reactions of radicals.
Biradicals and radical pairs: Generation and properties, lifetimes of singlet vs. triplet radical pairs, cage effects, CIDNP effect (theory and applications).
Carbenes and Nitrenes: Generation and detection by ESR-spectroscopy, zero-field splitting parameters, preparative applications.
Carbocations and Carbanions: kinds of formation, detection by 13C-NMR-spectroscopy, C-H-acidity of various compounds.
Dipolar intermediates: sulfur and phosphorus ylides (generation and synthetic applications), 1,3-dipols (various types, electronic structure, reactivity, synthetic scope).
Didehydroarenes, strained hydrocarbons and antiaromatic molecules: preparation and consecutive reactions.
Singlet oxygen: preparation and reactions (ene reaction, 2π+4π- and 2π+2π-cycloaddition, regioselectivity, experimental aspects).
J. March (ed.): "Advanced Organic Chemistry", fourth edition,
Wiley 1992
P. Renaud, M.P. Sibi (eds.): "Radicals in Organic Synthesis", Wiley,
2001.
H. Günther,:"NMR-Spectroskopie", Thieme, 1992.
N. L. Bauld: "Radicals, Ion Radicals, and Triplets", Wiley,
1997.
S. Kobayashi, K. A. Jørgensen, (eds.): " Cycloaddition Reactions in
Organic Synthesis", Wiley, 2001.