Area B: Catalysis

Area B of this CRC will be concerned with the probing of confinement effects and the development of a suitable linker technology to attach the catalyst within the pore.

The following catalyzed reactions, which are representatives for some of the most important transformations in organic chemistry, will be investigated in detail:

• Transfer Hydrogenation
• Olefin Metathesis
• Asymmetric 1,4- Addition

All the catalysts employed during the first funding period are well defined and established organometallic catalysts which have so far been used under homogeneous conditions. A fundamental mechanistic understanding of the homogeneous catalysis already exists, enabling us to gain full understanding of confinement effects.

Projects

B1 – Ru-catalysed H2-autotransfer processes

„Inner-pore“-tethered tetraaza-ruthenium-complexes for the directed hydrogen-autotransfer catalysis

In project B1 a (NNNN)Ru-complex will be linked to the inner pore-wall of materials from projects A1-A4 and A6. The catalytic performance of the hybrid materials will be analyzed as a function of pore diameter, shape, and geometry versus linker lengths and hydrophilicity of the material. H₂-autotransfer catalysis processes are intercepted transferhydrogenation processes; hence, an acceleration of the interception process, i.e. the condensation between ketone and amine, through fine-tuning of all the aforementioned parameters is expected. Cooperations with PIs from spectroscopy and theory (projects C1-C6) will aid to understand pore-specific confinement effects on H₂-autotransfer catalysis.

 

Principal Investigator: Prof. Dr. Bernd Plietker

B2 – Mo oder W-catalyzed olefin metathesis

Immobilized Molybdenum Imido, Tungsten Imido- and Tungsten Oxo Alkylidene N-Heterocyclic Carbene Complexes for Olefin Metathesis

Selected olefin metathesis reactions that are expected to be particularly susceptible to confinement effects will be studied. Both the influence of the pore surface (polar, non-polar, protic, aprotic) and the pore size, geometry and tortuosity of various mesoporous systems in combination with differently functionalized olefins (polar, non-polar, protic, aprotic) on the reactivity of N-heterocyclic carbene complexes of Mo-/W-imido- and W-oxo-alkylidenes immobilized in these mesoporous systems will be scrutinized.

 

Principal Investigator: Prof. Dr. Michael R. Buchmeiser

B3 – Asymmetric Rh-catalyzed 1,4-additions

Asymmetric catalysis with supported chiral olefin-rhodium complexes in defined porous networks

The aim is to understand and control chirality transfer, catalytic activity and mechanism of chiral diene-metal complexes covalently tethered inside a mesoporous material by using the asymmetric Rh-catalyzed 1,4-addition of boronic acids to enones as a benchmark system. The confinement effects resulting from a) the steric confinement of the catalyst and substrate in a pore of certain size and geometry, b) the polarity gradient between the inner pore surface and the catalyst in the centre and c) solvent interactions with inner pore surface and the ligand sphere will be examined by various experimental and theoretical methods.

 

Principal Investigator: Prof. Dr. Sabine Laschat

Other Project Areas

Visit Area A – Materials

Visit Area C – Analysis, Theory and Simulation