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 a range of reactions such as hydroformylation hydrogenation, coupling reactions (Heck, Suzuki), involving asymmetric catalysis and catalysis in aqueous media. Our research activities involve: i) catalysis by hybrid and hemilabile phosphorus ligands; ii) catalysis in air by phosphane-free ligands; iii) asymmetric catalysis; iv) catalysis by high energy techniques; v) catalysis by dendrimers; vi) aqueous catalysis, which are briefly described below:
Catalysis by hybrid and hemilabile phosphorus ligands
This project includes development of transition metal complexes with phosphines, phosphine oxides, phosphinites, mixed phosphine-phosphinites possessing additional potent donors such as oxygen, nitrogen, sulfur, selenium and their applications to homogeneous catalysis (hydroformylation, hydroaminomethylation, hydrogenation, Heck reaction). Achievement: Initiation of non cyclic-amino bisphosphinites as efficient ligands in the Rh-catalyzed hydroformylation. Selected complexes
. 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.
. E.I. Tolis, K.A. Vallianatou, F.J. Andreadaki, I.D. Kostas* Appl. Organomet. Chem. 2006, 20, 335.
. K.A. Chatziapostolou, K.A. Vallianatou, A. Grigoropoulos, C.P. Raptopoulou, A. Terzis, I.D. Kostas*, P. Kyritsis*, G. Pneumatikakis J. Organomet. Chem. 2007, 692, 4129.
. I.D. Kostas* Curr. Org. Synth. 2008, 5, 227.
Catalysis in air by phosphane-free ligands
Catalysis under phosphane-free conditions is of major interest for reactions under aerobic conditions. This project includes the development of novel palladium complexes with thiosemicarbazones or S-, Se-, Te-containing Schiff bases and their application to Heck and Suzuki reactions under aerobic conditions. Achievement: First use of thiosemicarbazones as ligands in the Pd-catalyzed coupling reactions. Selected complexes
. 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.
. I.D. Kostas*, B.R. Steele*, A. Terzis, S.V. Amosova, A.V. Martynov, N.A. Makhaeva Eur. J. Inorg. Chem. 2006, 2642.
This project includes the development of rhodium complexes with new chiral amino phosphite, diphosphite and phosphonite as well as phosphine(phosphite)-phosphoramidite ligands and their applications to enantioselective hydroformylation and hydrogenation. Achievement: Me-ANILAPHOS: a highly versatile chiral ligand for the Rh-catalyzed asymmetric olefin hydrogenation.
Selected complexes and ligands
. I.D. Kostas*, K.A. Vallianatou, J. Holz, A. Borner Appl. Organomet. Chem. 2005, 19, 1090.
. K.A. Vallianatou, I.D. Kostas*, J. Holz, A. Borner Tetrahedron Lett. 2006, 47, 7947. Selected comments for Me-AnilaPhos: (a) "excellent catalyst" (a critical review: L. Eberhardt, D. Armspach, J. Harrowfield, D. Matt Chem. Soc. Rev. 2008, 37, 839); (b) "highly versatile ligand class" (ALDRICH: D. Amoroso et al. Aldrichimica Acta, 2008, 41, 20).
. I.D. Kostas*, K.A. Vallianatou, J. Holz, A. Borner* Tetrahedron Lett. 2008, 49, 331.
. Book chapter: I.D. Kostas* "Other P/N-Ligands" (Chiral Bidentate Monophosphorus Ligands: Hybrid Monophosphorus Ligands - Bidentate P/NR2 Ligands - Other P/N-Ligands). In Phosphorus Ligands in Asymmetric Catalysis - Synthesis and Applications, A. Borner (Ed.), Wiley-VCH, Weinheim, 2008, Vol. 2, part IV, chapter 1.2, pp. 596-632.
Catalysis by high energy techniques
The project includes the application of a microwave irradiation to catalysis such as Suzuki coupling by palladium complexes with thiosemicarbazones inactive under a conventional heating.
I.D. Kostas*, G.A. Heropoulos*, D. Kovala-Demertzi*, P.N. Yadav, J.P. Jasinski, M.A. Demertzis, F.J. Andreadaki, G. Vo-Thanh, A. Petit, A. Loupy Tetrahedron Lett. 2006, 47, 4403.
Catalysis by dendrimers
The project deals with the development of functionalized triazine dendritic structures, and their applications to transition-metal catalysis (e.g. hydroformylation).
I.D. Kostas*, F.J. Andreadaki, E.A. Medlycott, G.S. Hanan, E. Monflier Tetrahedron Lett. 2009, 50, 1851.
Catalysis in aqueous media represents one of the most environmentally friendly homogeneously catalyzed processes, and allows simple separation and reuse of the catalyst. The present project includes the development of phosphane-free porphyrins, water-soluble in the presence of a base, and their use as ligands in metal-catalyzed reactions in neat water or water-organic solvent biphasic system. Achievements: First use of porphyrins as ligands in the Suzuki reaction and hydrogenation of á,â-unsaturated aldehydes in aqueous media.
I.D. Kostas*, A.G. Coutsolelos*, G. Charalambidis, A. Skondra Tetrahedron Lett. 2007, 48, 6688.
C. Staggel, G. Charalambidis, V. Varda, A.G. Coutsolelos*, I.D. Kostas* Eur. J. Inorg. Chem. 2010, submitted.