4th EucheMs chemistry congress

thursday, 30-Aug 2012
s804
chem. Listy 106, s587–s1425 (2012)
organic Chemistry, Polymers – ii
frontiers and Advances of organic Chemistry – ii
o - 4 9 4
BuiLdinG PriviLeGed CoMPLexity with
CASCAde trAnSforMAtionS: froM rinG- to
funCtionAL diverSity
K. KuMAr 1
1 Max-Planck-Institute for molecular Physiology, Chemical
Biology, Dortmund, Germany
Compound collections designed on the basis core scaffolds
of of natural products or the privileged motifs are expected to be
enriched in biochemical and biological activity. This calls for
developing efficient chemical transformations wherein further
molecular complexity (ring-structures and sp3 character) and
diversity (functional groups and carbo- and heterocyclic rings)
can be generated around these core-structures and which should
be amenable to compound collection format. [1] Cascade or domino
reaction sequences can rapidly built up molecular complexity and
thus could prove highly useful in synthesis of focused compound
libraries based on natural products core structures. [2] We have
successfully developed new cascade reaction sequences leading
to compound collections around benzopyrone, indoloisoquinoline
and indoloquinolizine core structures of natural products. This
presentation will summarize the implementation of different
modes of catalysis i.e. organo-, nucleophilic and Bronsted acid
and coinage metal catalysis to facilitate diverse cascade reactions
that transform the easily available substrates into the desired
complex natural product inspired compounds. A glimpse into how
such molecules help understand complex biological phenomenon [3]
and how the ring-diversity translates into functional-diversity shall
also be presented.
references:
1. K. Kumar, H. Waldmann, Angew. Chem. Int. Ed. 2009 48,
3224.
2. B. Baskar, P.-Y. Dakas, K. Kumar Org. Lett. 2011, 13,
1988.
3. H. Dückert, V. Pries, V. Khedkar, S. Menninger, H. Bruss,
A. W. Bird, Z. Maliga, A. Brockmeyer, P. Janning,
A. Hyman, S. Grimme, M. Schürmann, H. Preut, K.
Hübel, S. Ziegler, K. Kumar, H. Waldmann Nature Chem.
Biol. 2012, 8, 179.
Keywords: Alkaloids; Annulation; Domino reactions;
Molecular diversity; Natural products;
4 th EucheMs chemistry congress
frontiers and Advances of organic Chemistry – iii
o - 4 9 5
SynthetiC SuPrAMoLeCuLAr SySteMS At
worK
S. MAtiLe 1
1 University of Geneva, Department of Organic Chemistry,
Geneva, Switzerland
This lecture will summarize recent progress with design,
synthesis and evaluation of functional supramolecular systems.
The unifying theme is transport, topics of interest include the
transport of electrons and holes in photosystems, the transport of
anions and cations across lipid bilayers, and the transport of larger
molecules for sensing applications and cellular uptake.
To create oriented photosystems, we will have to learn how
to build with high precision directly on surfaces. To contribute
new solutions for this old problem, zipper assembly has been
introduced first. Combining LBL with stick-end technology,
zipper assembly has afforded double-channel architectures with
oriented antiparallel redox gradients. Looking for more
user-friendly alternatives, self-organizing surface-initiated
polymerization (SOSIP) has been developed next. This method
uses ring-opening disulfide exchange polymerization from
templating initiators on the surface. Hard to get but easy to use,
SOSIP is now being applied to topics such as templated
self-sorting for the transcription of 2D information into
3D architectures. Moreover, stack exchange has been introduced
to drill big holes into SOSIP architectures and build multi -
channel systems with multicomponent gradients, ultimately
composed of naphthalenediimides, perylenediimides, squaraines,
phthalocyanines, porphyrins and fullerenes.
As far as the transport of ions in lipid bilayers is concerned,
current interest focuses on the expansion our repertoire of
established interactions we have in hand to create function.
Examples include anion-macrodiple interactions, anion-π
interactions, and halogen bonds. To proof the functional relevance
of these less common interactions beyond any doubt, the size of
the transporters had to be reduced to an absolute minimum.
Driven to the extreme, this reductionism resulted in the
first example of clean, leakage-free, cooperative, highly
voltage-dependent and highly anion selective transport with the
smallest possible organic transporter, a molecule with one single
carbon only, and a boiling point of -22 ºC.
Keywords: photosystems; ion transport; surface-initiated
polymerization; templated self-sorting; halogen bonds;
AUGUst 26–30, 2012, PrAGUE, cZEcH rEPUbLIc