4th EucheMs chemistry congress

Poster Session 2
s1292
chem. Listy 106, s257–s1425 (2012)
Poster session 2 - organic chemistry
P - 0 8 5 8
new CAtALytiC hALoGenAtion StrAteGieS
for the GenerAtion of unuSuAL reACtivitieS
t. GuLder 1
1 RWTH Aachen university, Institute of Organic Chemistry,
Aachen, Germany
The halogenation of organic molecules is one of the most
widespread techniques for the functionalization of substrates,
which is often attributed to the good leaving group nature of
halogen atoms in a multitude of substrates. Compounds bearing
halogen atoms are thus versatile starting materials as well as
intermediates in organic syntheses. Due to the intrinsic properties
of the halogen substituents these molecules also play important
roles in medicinal chemistry, material science, and as agro
chemicals. Despite the broad application of halogenated
compounds, common strategies for the formation of
carbon-halogen bonds often suffer from severe drawbacks such
as stereo- and regioselectivity issues, making the development of
more selective and thus more atom economic and environmentally
friendly methods a rewarding goal.
Our research therefore addresses the problem of catalytic
halogenations by developing mild, generally applicable, and
selective catalytic methods for the directed oxidative formation
of carbon-halogen bonds. One aspect within our research program
tries to unlock hidden reactivities by catalytically activating
common halogenation reagents in order to access new structures
under mild conditions. Our recent advances in developing novel
halogenation strategies will be discussed.
Keywords: organocatalysis; halogenation; iodine(III); natural
products;
4 th EucheMs chemistry congress
P - 0 8 5 9
CheMo-enzyMAtiC ConCePtS for the
SyntheSiS of CoMPLex BACteriAL nAturAL
ProduCtS
t. A. M. GuLder 1 , A. hüLyA 1 , r. riChArz 1 , h. honG 1 ,
f. SChAeferS 1
1 University of Bonn, Kekulé Institute of Organic Chemistry and
Biochemistry, Bonn, Germany
The use of chemical entities isolated from natural sources
has been of particular significance for human health. This can be
rationalized by the often observed high selectivity and potency of
such natural products towards a distinct target. Their chemical
preparation is, however, often characterized by a high number of
individual synthetic steps using seemingly superfluous protective
groups, overall low chemical/optical yields, and the necessity of
expensive and sometimes highly toxic reagents. Novel approaches
towards the preparation of structurally complex metabolites by
combining the strengths of total organic synthesis with the
efficacy of nature’s strategies to generate molecular complexity
have the potential to solve these problems. Our research is
therefore focused on understanding and applying biosynthetic
enzymes as biocatalysts for the preparation of biomedically
relevant natural products in efficient biomimetic ways. Recent
achievements towards the chemo-enzymatic preparation of
synthetically challenging bacterial non-ribosomal peptides will be
discussed.
Keywords: Natural products; biosynthesis; Biomimetic
synthesis; Biocatalysis;
AUGUst 26–30, 2012, PrAGUE, cZEcH rEPUbLIc