Cluster: Integrale Konzepte der Katalyse (Teilbereich A 4)


Catalytic activation of ammonia and alkanes:
The Rhodium-catalyzed formation of aminoboranes will be coupled in a tandem reaction with a second process, such as an intra- or intermolecular hydroamination reaction. Both steps may be possible with the same Rh catalyst, but Ir catalysts might be more advantageous and will also be developed. In addition, we will pursuit the catalytic generation of olefins and H2 from alkanes as well as the catalytic derivatization of CH4. Both processes are based on a photo-chemical activation of an alkane by oxidative addition at Ir in a fluorinated solvent. Therefore, complexes which bear fluorinated alkyl chains have to be prepared in order to make the catalysts soluble. Methane can only be activated in a fluorinated phase, because otherwise a solvent activation would occur. In cooperation with the Driess group (TU Berlin) the synthesis of Ir complexes which feature a non-innocent ligand will be achieved. They might be able to induce new reaction pathways in the coordination sphere of the metal.

Catalytic activation of ammonia and alkanes:
The Rhodium-catalyzed formation of aminoboranes will be coupled in a tandem reaction with a second process, such as an intra- or intermolecular hydroamination reaction. Both steps may be possible with the same Rh catalyst, but Ir catalysts might be more advantageous and will also be developed. In addition, we will pursuit the catalytic generation of olefins and H2 from alkanes as well as the catalytic derivatization of CH4. Both processes are based on a photo-chemical activation of an alkane by oxidative addition at Ir in a fluorinated solvent. Therefore, complexes which bear fluorinated alkyl chains have to be prepared in order to make the catalysts soluble. Methane can only be activated in a fluorinated phase, because otherwise a solvent activation would occur. In cooperation with the Driess group (TU Berlin) the synthesis of Ir complexes which feature a non-innocent ligand will be achieved. They might be able to induce new reaction pathways in the coordination sphere of the metal.

Principal Investigators
Braun, Thomas Prof. Dr. (Details) (Cluster Unifying Concepts in Catalysis)

Participating external organizations

Duration of Project
Start date: 11/2007
End date: 10/2012

Research Areas
Anorganische Chemie

Publications
M. Ahijado-Salomon, T. Braun, I. Krossing, Dalton Trans. 2008, 5197-5206.
"Iridium Derivates of Fluornated Aromatics by C-H Activation: Isolation of Classical and Non-classical Hydrides"

M. Ahijado-Salomon, Ann-Katrin Jungton, T. Braun, Dalton Trans. 2009, 7669-7677.
"Activation of ethylene and ammonia at iridium: C-H versus N-H oxidative addition"

A.-K. Jungton, A. Meltzer, C. Präsang, T. Braun, M. Driess, A. Penner, Dalton Trans. 2010, 5436-5438.
"Addition of [(h5-C5Me5)IrH4] to a zwitterionic silylene: stepwise formation of iridium(V) and iridium(III)-silylene complexes"

A. Penner, T. Braun, Eur. J. Inorg. Chem. 2011, 2579-2587.
"Rhodium and Iridium Complexes with α-Diketimine Ligands: Oxidative Addition of H2 and O2"

P. Kläring, S. Pahl, T. Braun, A. Penner, Dalton Trans. 2011, 6785-6791.
"Facile oxidative addition of water at iridium: reactivity of trans-[Ir(4-C5NF4)(H)(OH)(PiPr3)2] towards CO2 and NH3"

A.-K. Jungton, P. Kläring, T. Braun, A. Eißler, Z. Anorg. Allg. Chem. 2012, 638, 505-511.
"Synthesis, Reactivity and Structure of Iridium Tetrafluoropyridyl Complexes: Ammonia Coordination and Activation"

A.-K. Jungton, C. Herwig, T. Braun, C. Limberg, Chem. Eur. J. 2012, 18, 10009-10013.
"Activation and Coordination of Ammonia at [Cp*Ir(H2)]: NMR and Matrix Isolation Studies"

M. Chilleck, T. Braun, R. Herrmann, B. Braun, Organometallics 2013, 32, 1067-1074.
"Zinc Complexes with the N-Donor-Functionalized Cyclopentadienyl Ligand C5Me4(CH2)2NMe2 "

M. Kuehnel, D. Lentz, T. Braun, Angew. Chem. 2013, 125, 3412-3433; Angew. Chem. Int. Ed. 2013, 52, 3328-3348.
"Synthesis of Fluorinated Building Blocks by Transition-Metal-Mediated Hydrodefluorination Reactions "

M. Ahrens, G. Scholz, T. Braun, E. Kemnitz, Angew. Chem. 2013, 125, 5436-5440; Angew. Chem. Int. Ed. 2013, 52, 5328-5332.
"Catalytic Hydrodefluorination of Fluoromethanes at Room Temperature by Silylium-ion-like Surface Species "

B. Rabay, T. Braun, J. P. Falkenhagen, Dalton Trans. 2013, 42, 8058-8065.
"Photolytic C–H activation and dehydrogenation of alkanes at cyclopentadienyl iridium complexes in a perfluorinated solvent "

A. Eißler, P. Kläring, F. Emmerling, T. Braun, Eur. J. Inorg. Chem. 2013, 27, 4775-4788.
"α-Dialdimine Complexes of Rhodium(I) and Iridium(I): Their Reactivity with Dioxygen and Dihydrogen"

M. A. Chilleck, L. Hartenstein, T. Braun, P. W. Roesky, B. Braun, Chem. Eur. J. 2015, 21, 2594-2602.
"Cationic Zinc Organyls as Precatalysts for Hydroamination Reactions"

Last updated on 2020-09-03 at 17:11