Eike Bauer
Dr.
Bauer received his Diploma (M.Sc.thesis degree) and his Ph.D from
the University of Erlangen-Nuremberg. He held a postdoctoral position
at the University of California, Riverside and a position as Visiting
Assistant Professor prior to joining the UM-St. Louis faculty
in Fall 2006.
bauere@umsl.edu
Office: B315i
Phone: (314) 516-5340
Fax:: (314) 516-5342
Webpage: www.eike-bauer.net
Research Interests
My research interests are in the area of Organic and Organometallic Chemistry. Organometallic chemistry is the study of compounds having metal-carbon bonds. Carbon-containing (organic) molecular fragments that are bonded to metal atoms often have unique geometries and reactivities on account of the metal's electronic properties. Organometallic compounds are important in catalysis, medicine, and the construction of molecular scale devices (nanoscience).
Olefin-
and Alkyne-Metathesis in the Coordination Spheres of Transition
Metal Complexes
Ring closing metathesis is a powerful tool for the synthesis of
small or large ring systems. The application of the ring closing
metathesis reaction (applying e.g. Grubb's olefin metathesis catalyst
or Schrock's alkyne metathesis catalyst) in the coordination sphere
of transition metal complexes provides a novel route to macrocyclic
metal complexes. These metal complexes are interesting classes
of compounds that might serve as starting point for molecular
scale devices.
I designed and synthesized several novel molecular architectures such as metal-containing big molecular ring systems or protected molecular wires. Those compounds might be a starting point for the construction of "molecular machines", such as motors, rotors or gyroscopes.
Phosphametallocenes
Phosphametallocenes are an interesting class of compounds, which
have similar properties than metallocenes. In phosphametallocenes,
one carbon of the coordinated cyclopentadienyl ligand is replaced
by phosphorus, forming a phospholylligand. Due to the phosphorus
in the ring system, unsymetrically substituted phospholylligands
form two diastereomers (rac and meso).
The lone
pair of the phosphorus in the coordinated phospholylligand is
capable of coordination to a transition metal such as Rhodium
(Scheme 2). It turned out that combination of a rac/meso mixture
of a phosphazirconocene I with a diasteropure Rhodium complex
leads to a single diastereomer of a bimetallic Rh-Zr complex.
(Hollis, T. K.; Wang, L.-S.; Tham, F. J. Am. Chem. Soc. 2000, 122, 11737).
Novel Carbene
Complexes and their Application as Catalysts in Organic Synthesis
Carbenes are a relatively new class of compounds which contain
divalent carbon atoms and a lone pair. Carbenes can serve as ligands
in transition metal complexes and influence their electronic properties.
Some of those complexes are excellent catalysts in reactions such
as hydrosilylation.
Hydrosilylation (addition of silanes to multiple C-C bonds) constitutes an interesting way to silanes. Silanes are important building blocks in organic synthesis. However, typically the addition of silanes to triple bonds provides a mixture of E, Z and alpha isomers. It turned out that the novel carbene complexes are capable of catalyzing hydrosilylation.
Selected Publications
"Air- and Water-Stable Catalysts for Hydroamination/Cyclization. Synthesis and Application of CCC-NHC Pincer Complexes of Rh and Ir" E. B. Bauer, G. T. S. Andavan, T. K. Hollis,R. R. Rubio, J. Cho, G. R. Kuchenbeiser, T. R. Helgert,C. S. Letko and F. S. Tham, Org. Lett. 2008, 1175.
"sp Carbon Chains Surrounded by sp3 Carbon Double Helices: Directed Syntheses of Wirelike Pt(CºC)nPt Moieties That Are Spanned by Two P(CH2)mP Linkages via Alkene Metathesis". L. de Quadras, E. B. Bauer, W. Mohr, J. C. Bohling, T. B. Peters, J-M. Martin-Alvarez, F. Hampel and J. A. Gladysz, J. Am. Chem. Soc. 2007, 129, 8296.
"sp Carbon chains surrounded by sp3 carbon double helices: wire-like Pt(CºC)nPt moieties that are spanned by two a,w-diphosphines that bear heteroatoms or alkyl substituents", L. de Quadras, E. B. Bauer, J. Stahl, F. Zhuravlev, F. Hampel, and J. A. Gladysz, New J. Chem. 2007, 31, 1594.
"Synthesis and Charaterization of a Free Phenylene Bis(N-Heterocylcic Carbene) and its di-Rh complex. Catalytic Activity of the di-Rh and CCC-NHC Rh Pincer complexes in Intermolecular Hydrosilylation of Alkynes." G. T. S. Andavan, E. B. Bauer, C. S. Letko, T. K. Hollis and F. S. Tham, J. Organomet. Chem. 2005, 5938.
"Toward a General Method for CCC N-Heterocyclic Carbene Pincer Synthesis: Metallation and Transmetallation Strategies for Activation of Three C-H bonds Concurrently." R. R. Rubio, G. T. S. Andavan, E. B. Bauer, T. K. Hollis, J. Cho, F. S. Tham and B. J. Donnadieu, Organomet. Chem. 2005, 5353.
"Alkene metatheses in transition metal coordination spheres: dimacrocyclizations that join trans positions of square-planar platinum complexes to give topologically novel diphosphine ligands." T. Shima, E. B. Bauer, F. Hampeland J. A. Gladysz, Dalton Transactions 2004, 7, 1012.
"Alkyne Metatheses in Transition Metal Coordination Spheres: Convenient tungsten- and molybdenum-catalyzed syntheses of novel metallamacrocycles." E. B. Bauer, F. Hampel and J. A. Gladysz, Advanced Synthesis & Catalysis 2004, 346, 812.
"Metal-Catalyzed Olefin Metathesis in Metal Coordination Spheres." E. B. Bauer and J. A. Gladysz, in Handbook of Metathesis, R. H. Grubbs, Ed.; Wiley/VCH, New York, 2003, 2, 403.
"sp Carbon Chains Surrounded by sp3 Carbon Double Helices: An Unprecedented New Class of Molecules that are Accessible by Self-Assembly and Models for "Insulated" Molecular-Scale Devices." J. Stahl, J. C. Bohling, E. B. Bauer, T. B; Peters, W. Mohr, J. M. Martín-Alvarez, F. Hampel and J. A. Gladysz, Angew. Chem. 2002, 114, 1951; Angew. Chem. Int. Ed. 2002, 41, 1871.
"Olefin Metatheses in Metal Coordination Spheres: Versatile New Strategies for the Construction of Novel Monohapto or Polyhapto Cyclic, Macrocyclic, Polymacrocyclic, and Bridging Ligands." J. Ruwwe, J. M. Martín-Alvarez, C. R. Horn, E. B. Bauer, S. Szafert, T. Lis, F. Hampel, P. C. Cagle and J. A. Gladysz, Chem. Eur. J. 2001, 7, 3931.