The group of Prof. Dr. Andreas Kirschning is focused on natural product chemistry employing means and techniques of both chemistry and biology, while another main field of research represents the development of enabling methods in organic synthesis with emphasis on microreactor technology. |
 → Latest publications S. Ceylan, A. Kirschning: K. Mennecke, A. Kirschning: S. Eichner, H. G. Floss, F. Sasse, A. Kirschning: F. Gallier, H. Hussain, A. Martel, A. Kirschning, G. Dujardin: A. Kirschning (Editor): F. Taft, M. Brünjes, T. Knobloch, H. G. Floss, A. Kirschning: A. Kirschning, S. Luiken, A. Migliorini, M. A. Loreto, M. Vogt: M. Bock, R. Dehn, A. Kirschning: → Cooperations
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The preparation of monolithic polyionic supports which serve as efficient heterogeneous supports for palladium(0) nanoparticles is described. These functionalized polymers were incorporated inside a flow reactor and employed in Suzuki-Miyaura and Heck cross couplings under continuous flow conditions.
The feeding of aromatic and heteroaromatic amino acids to an AHBA-blocked mutant of S. hygroscopicus yielded new analogues of the highly potent Hsp90 inhibitor geldanamycin. Except for a pyridine-geldanamycin derivative, all new compounds had strong antiproliferative activity (IC50 values in the nM range).
Chiral enamides, easily prepared in one step from a cyclic ketone and an oxazolidinone, are successfully employed in high-yielding, endo, and facially selective Hetero-Diels-Alder reactions involving activated oxadienes and Siever's reagent as catalyst. From the resulting bicyclic heteroadducts, a novel and efficient asymmetric modification for the Robinson annulation of cyclic monoketones is described.
The environment in which synthesis is conducted has hardly changed over the last centuries: reactions are still typically performed batchwise in standardized glassware which has commonly been in use since the time of Justus von Liebig. In contrast, the use of flow-through processes is still rather restricted to the production site. Only recently have chemists in industry as well as in academia begun to focus on the development of flow devices for laboratory use and hence for industrial applications. The developments in flow techniques using mini and micro flow reactors have initiated changes that will pave the way for a technological step forward in chemical synthesis similar to that which took place in analytical chemistry and purification when chromatography started to conquer laboratories several decades ago, finally taking them by storm. This thematic series on chemistry in flow systems, which includes original research papers and a review, mainly from the organic chemist's perspective, will become part of this development, and we are happy to have assembled research by the leading research groups in this area from all over the world.
The timing of introduction of the unusually placed Δ-11,13 diene system in ansamitocin (AP) biosynthesis was probed by synthesizing optically active potential tri- and tetraketide intermediates as their SNAC thioesters. An AP-nonproducing mutant Actinosynnema pretiosum was complemented by the R enantiomer of the triketide and by the tetraketide with rearranged double bonds, but not by the tetraketide carrying the double bonds in conjugation to the thioester function. The results show that the double bonds are installed in their final positions during processing of the nascent polyketide on module 3 of the asm PKS and that KS4 of the PKS acts as a gatekeeper which accepts only a tetraketide with shifted double bonds as substrate for further processing.
The first 1,2-Brook rearrangements with bis(dimethyl-phenylsilyl) ketone, initiated after addition of different C- and S-nucleophiles, are described. The resulting, newly formed carbanion can be trapped with electrophiles thus paving the way for utilizing bissilyl ketones as formyl dianion equivalents in the future.
After AIDS, tuberculosis (TB) is the infectious disease with the highest mortality worldwide. The efficacy of first-line anti-TB drug regiments is often reduced owing to drug resistance. Additionally, the ability of Mycobacterium tuberculosis to persist in latent infections necessitates the development of alternative antibiotics, preferably with novel modes of action.
