Book of Abstracts - Ruhr-Universität Bochum

P-27
ISBOMC `10 5.7 – 9.7. 2010 Ruhr-Universität Bochum
Variable Binding of Heterodinuclear (Cu, Fe) Organometallics to N and O Donor
Functions of Guanine, Pterin, Lumazine and Alloxazine Heterocycles
Rajkumar Jana, a Biprajit Sarkar, a Jan Fiedler, b and Wolfgang Kaim *a
a Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70550, Stuttgart,
Germany; b J. Heyrovský Institute of Physical Chemistry, v.v.i., Academy of Sciences of the Czech
Republic, Dolejškova 3, 182 23 Prague 8, Czech Republic. E-mail: jana@iac.uni-stuttgart.de
Co-ordination compounds of the first row transition elements with small biorelevant heterocycles such
as coenzymes, vitamins, and also nucleobases are frequently labile, precluding the isolation and
structural identification of species present in solution equilibria. In contrast, complexes of the heavier
d block elements are often inert as exemplified by the platinum and platinum metal coordination
chemistry of nucleobases 1 and coenzymes 2 . Herein we wish to report a number of first row transition
metal compounds which owe their stability to the use of a particular kind of organometallic complex
fragments, viz., [(dopf)Cu] + , dopf = 1,1`-bis(diorganylphosphino)ferrocene.
Bu t OC
H
N
H
The dopf ligands are being extensively used as scaffolding chelate ligands in catalysis 3, 4 , sometimes
using their propensity for reversible one-electron oxidation at the ferrocene iron site. Our experience
especially with the dppf ligand (dppf = 1,1`-bis(diphenylphosphino)ferrocene) in heterobimetallic
[(dppf)Cu] + to stabilize complexes with unreduced strong acceptors such as α-azoimines 5 or oquinones
6 has prompted us to explore the coordination of [(dppf)Cu] + and [(dippf)Cu] + , dippf = 1,1`bis(diisopropylphosphino)ferrocene,
with other small biorelevant unsaturated molecules containing the
lumazine, isoalloxazine, pterin and guanine heterocyclic structures. Synthesis and structural
characterization will be reported as will be electrochemical studies on oxidation (ferrocene) and
reduction (heterocycles).
References
N
O
N
Fe
R2P + PR2 Cu
N
N
Me
Bu t OC
H
N
H
N
Fe
R2P + PR2 Cu
O
N
N
N
1. (a) D. Montagner, E. Zangrando, B. Longato, Inorg. Chem. 2008, 47, 2688-2695. (b)
Cisplatin: Chemistry and Biochemistry of a Leading Anticancer Drug; B. Lippert, Ed.; Wiley-VCH,
Weinheim, 1999.
2. Bioorganometallics: Biomolecules, Labelling, Medicine; G. Jaouen, Ed.; Wiley-VCH, Weinheim,
2006.
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Chem. Soc. 2000, 122, 4618-4630.
4. M. S. Driver, J. F. Hartwig, J. Am. Chem. Soc. 1997, 119, 8232-8245.
5. S. Roy, M. Sieger, B. Sarkar, B. Schwederski, F. Lissner, T. Schleid, J. Fiedler, W. Kaim, Angew.
Chem. Int. Ed. 2008, 47, 6192-6194.
6. S. Roy, B. Sarkar, D. Bubrin, M. Niemeyer, S. Zalis, G. K. Lahiri, W. Kaim, J. Am. Chem. Soc.
2008, 130, 15230-15231.
85
Me
N
O
Fe
R2P + PR2 O
Cu
N
N N
Me
Me
N
O
Fe
R2P + PR
O
Cu 2
N
N N
Me
Me
Me