Rational design of catalysts for asymmetric transformations is alongstanding challenge in the field of catalysis. In the current contribution we report ac atalyst in which ah ydrogen bond between the substrate and the catalyst plays ac rucial role in determining the selectivity and the rate of the catalytic hydrogenation reaction, as is evident from ac ombination of experiments and DFT calculations.D etailed insight allowed in silico mutation of the catalyst such that only this hydrogen bond interaction is stronger,p redicting that the new catalyst is faster.I ndeed, we experimentally confirmed that optimization of the catalyst can be realized by increasing the hydrogen bond strength of this interaction by going from aurea to phosphine oxide H-bond acceptor on the ligand.The asymmetric hydrogenation reaction is undoubtedly the most powerful asymmetric transformation for the fine chemical industry as it provides ar ather general strategy to create chiral centers in organic molecules.[1] As the synthesis of the desired products cannot always be reached using the existing catalysts,t he search for new methods and concepts has received considerable attention.[2] Combinatorial chemistry approaches and high-throughput catalyst screenings have been demonstrated to be increasingly important.[3] Fort he generation of catalyst libraries based on chiral ligands,the use of supramolecular ligand building blocks that form bidentate ligands by self-assembly is apowerful strategy as the number of catalysts grows exponentially with the number of synthesized building blocks. [4] Next to interactions between the two ligand building blocks,hydrogen bonding between functional groups of the substrate and the ligands at the metal complex can contribute to catalyst selectivity.[5] One of the major goals in the area of asymmetric hydrogenation, or more general in the field of catalysis,would be the rational design of transition metal catalysts.Although for several catalyst systems detailed knowledge on the reaction mechanism has been obtained, [6] prediction of the catalyst properties is still very challenging. [7] However,w hen the selectivity of ac atalytic reaction is controlled by supramolecular interactions,f urther rational optimization could be performed, guided by theoretical prediction. Herein we report the first example of rational design of ac atalyst for the asymmetric hydrogenation reaction by optimization of the supramolecular interactions between the substrate and the catalyst, leading to enhanced activity and superior selectivity in the hydrogenation of hydroxy-functionalized di-and trisubstituted alkenes.I n order to allow ar ational approach, the reaction mechanism of the supramolecular catalyst used was investigated by means of X-ray crystallography,N MR spectroscopy,k inetic studies,a nd DFT calculations of the reaction pathway. Subsequently,t he relevant supramolecular interactions between the substrate and the catalyst were optimized in silico,r esulting in the rational design of as econd generation of ca...

The reaction mechanism of the asymmetric hydrogenation of functionalized alkenes catalyzed by a supramolecular rhodium complex has been investigated. In-depth NMR analysis combined with X-ray crystal structure determination show that hydrogen bonds are formed between the catalyst and the substrate in the early stages of the mechanism. Detailed kinetic data obtained from UV–vis stopped-flow experiments and gas-uptake experiments confirm that the hydrogen bonds are playing a crucial role in the mechanism. A complete DFT study of the various competitive paths of the reaction mechanism allowed us to identify how these hydrogen bonds are involved in the determining steps of the reaction.

Rational design of catalysts for asymmetric transformations is alongstanding challenge in the field of catalysis. In the current contribution we report ac atalyst in which ah ydrogen bond between the substrate and the catalyst plays ac rucial role in determining the selectivity and the rate of the catalytic hydrogenation reaction, as is evident from ac ombination of experiments and DFT calculations.D etailed insight allowed in silico mutation of the catalyst such that only this hydrogen bond interaction is stronger,p redicting that the new catalyst is faster.I ndeed, we experimentally confirmed that optimization of the catalyst can be realized by increasing the hydrogen bond strength of this interaction by going from aurea to phosphine oxide H-bond acceptor on the ligand.The asymmetric hydrogenation reaction is undoubtedly the most powerful asymmetric transformation for the fine chemical industry as it provides ar ather general strategy to create chiral centers in organic molecules. [1] As the synthesis of the desired products cannot always be reached using the existing catalysts,t he search for new methods and concepts has received considerable attention. [2] Combinatorial chemistry approaches and high-throughput catalyst screenings have been demonstrated to be increasingly important. [3] Fort he generation of catalyst libraries based on chiral ligands,the use of supramolecular ligand building blocks that form bidentate ligands by self-assembly is apowerful strategy as the number of catalysts grows exponentially with the number of synthesized building blocks. [4] Next to interactions between the two ligand building blocks,hydrogen bonding between functional groups of the substrate and the ligands at the metal complex can contribute to catalyst selectivity. [5] One of the major goals in the area of asymmetric hydrogenation, or more general in the field of catalysis,would be the rational design of transition metal catalysts.Although for several catalyst systems detailed knowledge on the reaction mechanism has been obtained, [6] prediction of the catalyst properties is still very challenging. [7] However,w hen the selectivity of ac atalytic reaction is controlled by supramolecular interactions,f urther rational optimization could be performed, guided by theoretical prediction. Herein we report the first example of rational design of ac atalyst for the asymmetric hydrogenation reaction by optimization of the supramolecular interactions between the substrate and the catalyst, leading to enhanced activity and superior selectivity in the hydrogenation of hydroxy-functionalized di-and trisubstituted alkenes.I n order to allow ar ational approach, the reaction mechanism of the supramolecular catalyst used was investigated by means of X-ray crystallography,N MR spectroscopy,k inetic studies,a nd DFT calculations of the reaction pathway. Subsequently,t he relevant supramolecular interactions between the substrate and the catalyst were optimized in silico,r esulting in the rational design of as econd generation of catalysts...

A series of bisphosphine monoxides and a phosphoramidite have been used for the preparation of supramolecular ligands. A structural analysis of the complexes using NMR spectroscopy and DFT calculations revealed the formation of strong hydrogen bonding between the two ligands. The complexes have been evaluated in the hydrogenation of several functionalized alkenes, leading to very high enantioselectivity for the substrates bearing a hydroxyl group. Also, kinetic studies showed that enhanced reaction rates of hydrogenation are observed in comparison with the supramolecular catalytic systems based on urea groups. In-depth NMR spectroscopy experiments and computational studies have highlighted the crucial role of the hydrogen bond between the phosphine oxide ligands and the substrate during the hydrogenation reaction.