TRANSITION-METAL HOMOGENEOUS CATALYSIS

Transition-metal homogeneous catalysis is a highly competitive research field with enormous academic and industrial interest. Our investigations include the development of transition-metal complexes with novel ligands and their evaluation in reactions such as:

Hydroformylation, recognized as the largest volume industrial application of homogeneous catalysis employing organometallic catalysts and the best technology for the synthesis of aldehydes from olefins.
Hydroaminomethylation, a domino hydroformylation-reductive amination reaction, which leads to secondary and tertiary amines.
Hydrogenation, one of the most well-established homogeneously catalysed processes.
Cross-coupling reactions, e.g. the Heck and Suzuki reactions are among the most versatile tools for C-C bond forming reactions.

The research activities of the group are summarised below while for more details visit the page describing the research activities of  Dr. Kostas):

Catalysis by multidentate and hemilabile phosphorus ligands
The project includes the development of transition metal complexes with  multidentate and hemilabile phosphorus ligands possessing additional potent donors such as oxygen, nitrogen, sulfur and selenium, and their applications to homogeneous catalysis. 

Recent selected publications
I.D. Kostas J. Organomet. Chem. 2001, 626, 221
I.D. Kostas J. Organomet. Chem. 2001, 634, 90
I.D. Kostas Inorg. Chim. Acta 2003, 355, 424
I.D. Kostas, B.R. Steele, A. Terzis, S. V. Amosova Tetrahedron 2003, 59, 3467
I.D. Kostas, B.R. Steele, F.J. Andreadaki, V.A. Potapov Inorg. Chim. Acta 2004, 357, 2850

Catalysis in air by phosphine-free ligands
Catalysis under phosphine-free conditions is of major interest for reactions under aerobic conditions. This project in collaboration with Prof. D. Kovala-Demertzi (University of Ioannina) includes the development of novel palladium complexes with thiosemicarbazones and their application for the first time to Heck and Suzuki cross-coupling reactions under aerobic conditions.

Recent publications
I.D. Kostas, F.J. Andreadaki, D. Kovala-Demertzi, C. Prentjas, M.A. Demertzis Tetrahedron Lett. 2005, 46, 1967
D. Kovala-Demertzi, P.N. Yadav, M.A. Demertzis, J.P. Jasinski, F.J. Andreadaki, I.D. Kostas Tetrahedron Lett. 2004, 45, 2923.

Catalysis by unmodified rhodium complexes
The project in collaboration with Prof. J. Vohlidal (Charles University, Prague) and Dr. P. Kyritsis (University of Athens) deals with the ultrasound-assisted synthesis of dinuclear aryloxide- and carboxylate-bridged rhodium complexes and their evaluation in the hydroformylation reaction.

Recent publication
I.D. Kostas, K.A. Vallianatou, P. Kyritsis, J. Zednik, J. Vohlidal Inorg. Chim. Acta 2004, 357, 3084

Asymmetric catalysis
This project in collaboration with Prof. A. Boerner (Leibniz-Institut fuer Organische Katalyse an der Universitat Rostock) involves the development of rhodium complexes with new chiral amino diphosphite, phosphonite and phosphonite-phosphoramidite ligands and their applications to enantioselective hydroformylation and hydrogenation.

Aqueous biphasic catalysis (Green Chemistry)
Aqueous biphasic catalysis represents one of the most environmentally friendly homogeneously catalysed processes. The present project includes the development of water-soluble rhodium complexes with new diphosphines possessing quaternary amino groups and their application to aqueous biphasic hydroformylation.

Catalytic studies are also under way based on dendrimeric molecules, click here for more details.