IMPROVED ACTIVITY AND ENANTIOSELECTIVITY OF HETEROGENIZED MOLECULAR CATALYSTS

SSCI-VIDE+ING+JEC:RRJ:BCH:FWI:EQD; International audience; Heterogeneous catalysis allows to circumvent the problem of separation of the catalyst from the products and to simplify its recyclability. The integration of the catalytically active centers into a solid support without loss of performance compared to the homogeneous analog is still a major challenge. To change the paradigm of molecular catalytic processes for fine chemical synthesis and green fuel production, we introduced recently the concept of solid porous macroligand for heterogenized molecular catalysis.[1] Having molecularly-defined active sites, porous macroligands have been found to drive the activity and the selectivity of heterogenized catalytic processes on a similar way as molecular ligands but with the advantage of the structuration in a three-dimensional framework[2] and the confinement within a porous nanospace.[3] We first demonstrated that the design of highly efficient heterogeneous catalyst based on porous organic polymer (POP) and metal-organic frameworks (MOF) is driven by the Hammett parameter of bipyridine-chelating macroligand as demonstrated for the photoreduction of carbon dioxide, with turnover frequencies among the highest reported for heterogeneous photocatalytic formate production.[2,4] More recently, we showed that the heterogenization of a chiral benzene ruthenium molecular complex within the MIL-101-NH-Gly-Pro cavity allows a threefold enhancement of the selectivity in the catalyzed asymmetric transfer hydrogenation of ketone compared to homogenous analogue system.[3] The DFT-level computations supported by experimental data highlight the crucial role of the MOF as a macroligand for the ruthenium catalyst to direct the enantioselectivity of the reaction. In these two cases, accurate descriptor at the molecular level can be used to predict activity and selectivity of confined molecular catalysts within macroligands.References:1.F. M. Wisser, Y. Mohr, E. A. Quadrelli, J. Canivet, ChemCatChem 2020, 12, 1270–1275.2.F. M. Wisser, M. Duguet, Q. Perrinet, A. C. Ghosh, M. Alves‐Favaro, Y. Mohr, C. Lorentz, E. A. Quadrelli, R. Palkovits, D. Farrusseng, C. Mellot‐Draznieks, V. de Waele, J. Canivet, Angew. Chem. Int. Ed. 2020, 59, 5116–5122.3.J. Canivet, E. Bernoud, J. Bonnefoy, A. Legrand, T. Todorova, E. A. Quadrelli, C. Mellot-Draznieks, Chem. Sci. 2020, 11, 8800–8808.4.F. M. Wisser, P. Berruyer, L. Cardenas, Y. Mohr, E. A. Quadrelli, A. Lesage, D. Farrusseng, J. Canivet, Acs Catal. 2018, 8, 1653–1661.