Twitter : @raynal_cnrs
|Current group members from left to right : |
Matthieu Raynal, Diana Deaibess (PhD), Antoine Perennes (PhD), Huanjun Kong (PhD), Antonio Valverde González (post-doc), Ran Chen (PhD)
|Images showcasing the current research topics (I) and (II), see below for description. A BTA helical catalyst composed of two different monomers is drawn at the upper right (a single hydrogen bond array is shown instead of three). |
Research topics : supramolecular polymers, hydrogen-bonded assemblies, asymmetric catalysis, supramolecular chirality
Summary of the main achievements :
Since 2012, our research interests focus on the following topics :
(1) Supramolecular catalysis dealing with the use of hydrogen-bonded polymers as platforms for asymmetric catalysis.
The main achievements have been recently summarized in [P31] and book chapter [BC3]. We have been invited to contribute to the Special Issue “New Concepts in Homogeneous Catalysis” in ChemCatChem[P31], to the Themed Issue on Switchable Catalysis in Chem. Commun.[P26] and to the 2021 Emerging Investigator Issue of Catal. Sci. Technol.[P38]
We developed hydrogen-bonded supramolecular polymers adopting a helical conformation on their main chain as scaffolds for asymmetric catalytic reactions. We showed that the enantioselectivity of copper and rhodium catalysts can be modulated by mixing benzene 1,3,5-tricarboxamide (BTA) monomers able to self-associate into chiral helices in solution. The novelty of our approach stems from the fact that the structure of the polymers and the outcome of the catalytic reaction are intimately interrelated.
Chirality induction and “sergeants-and-soldiers” effect (Figure I) :
In the proof-of-concept published in J. Am. Chem. Soc. in 2013, we designed a BTA monomer that combines a diphenylphosphino unit connected to the central BTA ring through a rigid meta-phenylene linker and two (S)-1-methylheptyl side chains. The hydrogenation of an activated olefin, dimethyl itaconate, was selected as this reaction is conveniently promoted at room temperature and low pressure of dihydrogen. Our study revealed that the enantioselectivity observed with enantiopure BTA ligands coordinated to rhodium stems from the supramolecular chirality of the in-situ formed helices, not from direct contribution of the remote stereogenic centres.[P10] In addition, the selectivity can be modulated by combining BTA monomers. This property was further corroborated by establishing that the “sergeants-and-soldiers” effect is operative in this class of helical catalysts. Enantiopure BTAs derived from amino esters (ester BTAs) act as very efficient chirality inducers when mixed with a phosphine-functionalized achiral BTA monomer. A substoichiometric amount of an ester BTA (referred to as the “sergeant”) relatively to the ligand (the “soldier”) can control the optical purity and handedness of the helical rhodium phosphine complexes.[P19] More precisely, close to the optimal selectivity (78% e.e.) was achieved with the mixture containing only 20% of sergeant, i.e. one enantiopure molecule for two achiral rhodium atoms. To the best of our knowledge, this was the first time that a chiral inducer could be used in a substoichiometric amount relative to a ligand without significantly deteriorating the enantioselectivity of an organometallic transformation. Thorough characterization of these two-component mixtures helped to elucidate the following point : the configuration of the main enantiomer and the degree of enantioinduction obtained throughout the catalytic process are related to the handedness and optical purity, respectively, of the helices supporting the intrinsically achiral catalytic centres. Consequently, the sergeants-and-soldiers effect was implemented with a BTA ligand that contains a PPh2 group connected to the BTA ring through a para-phenylene linker. The resulting “sergeants-and-soldiers” mixtures were implemented in the copper-catalysed hydrosilylation (HS) of ketones[P32] and hydroamination (HA) of arenes.[P38] In this case, the addition of a complementary achiral BTA monomer led to a dramatic improvement of the “sergeants-and-soldiers” effect since homochiral helical polymers and catalysts are obtained which contain as low as 0.5% of sergeants and 2.5% for HS and HA reactions, respectively. Remarkably, enantioselectivities reach over 75% e.e. under these conditions operating with ppm levels of chiral species. The nature of the sergeant is also particularly important in these systems, the chemical group connected to their stereogenic centres dictates whether the sergeant will act as an intercalator or a chain stopper of the BTA ligand stacks.[P34]Accordingly, ester BTAs derived from Leucine and Cyclohexylalanine proved to mix efficiently within the stacks of the ligand, thus imparting a suitable chiral environment for the catalytic reaction.
Related publications :
[P10] : “Tunable asymmetric catalysis through ligand stacking in chiral rigid rods.”
Matthieu. Raynal,* François Portier, Piet W. N. M. van Leeuwen, and Laurent Bouteiller
J. Am. Chem. Soc., 2013, 135, 17687-17690.
[P19] : “Correlation between the selectivity and the structure of an asymmetric catalyst built on a chirally amplified supramolecular helical scaffold.”
Alaric Desmarchelier, Xavier Caumes, Matthieu Raynal,* Anton Vidal-Ferran, Piet W. N. M. van Leeuwen, and Laurent Bouteiller
J. Am. Chem. Soc., 2016, 138, 4908-4916
Highlight in Nature Nanotechnology : highlight in Nat.Nanotechnol.
[P31] : “Catalysts Supported by Homochiral Molecular Helices : A New Concept to Implement Asymmetric Amplification in Catalytic Science.”
Yan Li, Laurent Bouteiller and Matthieu Raynal*
ChemCatChem, 2019, 11, 5212-5226.
Invitation, Special Issue on New Concepts in Homogeneous Catalysis.
[P32] : “Emergence of Homochiral Benzene-1,3,5-tricarboxamide Helical Assemblies and Catalysts upon Addition of an Achiral Monomer.”
Yan Li, Ahmad Hammoud, Laurent Bouteiller and Matthieu Raynal*
J. Am. Chem. Soc., 2020, 142, 5676-5688.
[P34] : “Dissecting the Role of the Sergeants in Supramolecular Helical Catalysts : From Chain Capping to Intercalation.”
Mayte A. Martínez-Aguirre, Yan Li, Nicolas Vanthuyne, Laurent Bouteiller, and Matthieu Raynal*
Angew. Chem. Int. Ed., 2021, 60, 4183-4191.
[P38] : “Asymmetric hydroamination with far fewer chiral species than copper centers achieved by tuning the structure of supramolecular helical catalysts.”
Paméla Aoun, Ahmad Hammoud, Mayte A. Martínez-Aguirre, Laurent Bouteiller, Matthieu Raynal*
Catal. Sci. Technol., 2022, 12, 834-842.
This article is part of the themed collection : Emerging Investigator Series
[BC3] “Supramolecular Helical Catalysts”, M. Raynal, L. Bouteiller, in Supramolecular Catalysis : New Directions and Developments, First Edition, Eds. P. W. N. M. van Leeuwen and M. Raynal, WILEY-VCH GmbH, 12/2021, https://onlinelibrary.wiley.com/doi/10.1002/9783527832033.ch7
Dynamic and switchable helical catalysts (Figure II) :
By exploiting the inherent dynamicity of the aforementioned hydrogen-bonded catalysts, we demonstrated the possibility of modulating the selectivity of a catalytic reaction in situand in real time. We vary the length of helical BTA catalysts in a reversible manner by first adding chloride anions and then removing them from the solution phase through a salt metathesis reaction. In consequence, the BTA catalyst promoted the reaction alternatively with a certain degree of selectivity (29–52% e.e.) and no or very poor selectivity (0–6% e.e.) as expected for the runs for which chloride ions were absent or present in solution, respectively.[P26] Dual stereocontrol of the catalytic reaction was also achieved by changing the nature of the major enantiomer of the sergeant in the helical co-assemblies during the course of the reaction. Thanks to the combined action of the sergeants, the handedness of the helices and thus the direction of the catalytic reaction are switched during the hydrosilylation of a mixture of two aromatic ketones.[P24]
Related publications :
[P24] : “Real-Time Control of the Enantioselectivity of a Supramolecular Catalyst Allows Selecting the Configuration of Consecutively Formed Stereogenic Centers.”
Jeremy M. Zimbron, Xavier Caumes, Yan Li, Matthieu Raynal,* Christophe M. Thomas, and Laurent Bouteiller
Angew. Chem. Int. Ed., 2017, 56, 14016-14019.
Highlight in Chemistry World : highlight
[P26] : “Modulation of catalyst enantioselectivity through reversible assembly of supramolecular helices.”
Yan Li, Xavier Caumes, Matthieu Raynal,* and Laurent Bouteiller
Chem. Commun., 2019, 55, 2162-2165.
Invitation, Themed Collection on Switchable Catalysis.
(2) Synthesis, characterization and rationalization of functional chiral supramolecular assemblies (Figure III).
The second topic deals with the characterization of mostly chiral hydrogen-bonded species, polymers and co-polymers in crystalline form, in gel, in bulk and in solution and the structure-property relationships between the structure of the monomers and the structural properties of the (co)-polymers. It notably includes the combined experimental and MM/MD characterization of the unusual assembly behaviour of ester BTAs,[P15] or bis-urea monomers[P16] and the characterization of the aforementioned helical catalysts.[P34] The chemical and chiral nature of the group connected to the stereogenic centres of ester BTAs has a great influence on the structure of the related self-assemblies : various types of dimeric structures[P20],[P21],[P35] or extra-stabilized helical stacks[P27] have notably been characterized. A particular interest has been dedicated to induce a chiral environment to linear gold[P18] and square-planar platinum[P37] complexes located at the periphery of sergeants-and-soldiers type assemblies. More recently, N-substituted benzene-1-urea-3,5-biscarboxamide (BUBA) monomers, which consist of one urea and two carbon-connected amide functions linked to an aromatic ring, have been introduced as an easily accessible class of C2-symmetric supramolecular synthons which exhibit good sergeants-and-soldiers effect.[P29]
Related publications :
[P15] : “Revisiting the assembly of amino ester-based benzene-1,3,5-tricarboxamides : chiral rods in solution.”
Alaric Desmarchelier, Matthieu Raynal,* Patrick Brocorens, Nicolas Vanthuyne, and Laurent Bouteiller*
Chem. Commun., 2015, 51, 7397-7400.
[P16] : “Structural control of bisurea-based supramolecular polymers : influence of an ester moiety.”
Mohammed Dirany, Virgile Ayzac, Benjamin Isare, Matthieu Raynal,* and Laurent Bouteiller*
Langmuir, 2015, 31, 11443-11451
[P18] : “Induced circular dichroism in phosphine gold(I) arylacetylide urea complexes through hydrogen-bonded chiral co-assemblies.”
Julien Dubarle-Offner, Jamal Moussa, Hani Amouri,* Benjamin Jouvelet, Laurent Bouteiller, and Matthieu Raynal*
Chem. Eur. J., 2016, 22, 3985-3990
[P20] : “Tuning the nature and stability of self-assemblies formed by ester benzene 1,3,5-tricarboxamides : the crucial role played by the substituents.”
Alaric Desmarchelier, Bruno Giordano Alvarenga, Xavier Caumes, Ludovic Dubreucq, Claire Troufflard, Martine Tessier, Nicolas Vanthuyne, Julien Idé, Thomas Maistriaux, David Beljonne, Patrick Brocorens, Roberto Lazzaroni, Matthieu Raynal,* and Laurent Bouteiller
Soft Matter, 2016, 12, 7824-7838.
[P21] : “Tuning the structure of 1,3,5-benzene tricarboxamide self-assemblies through stereochemistry.”
Xavier Caumes, Arianna Baldi, Geoffrey Gontard, Patrick Brocorens, Roberto Lazzaroni, Nicolas Vanthuyne, Claire Troufflard, Matthieu Raynal,* and Laurent Bouteiller
Chem. Commun., 2016, 52, 13369-13372.
Invitation, Themed issue : Chirality at the Nanoscale.
[P27] : “Extra hydrogen bonding interactions by peripheral indole groups stabilize benzene-1,3,5-tricarboxamide helical assemblies.”
Gaëtan Basuyaux, Alaric Desmarchelier, Geoffrey Gontard, Nicolas Vanthuyne, Jamal Moussa,* Hani Amouri, Matthieu Raynal* and Laurent Bouteiller
Chem. Commun., 2019, 55, 8548-8551.
[P29] : “N-Substituted Benzene-1-Urea-3,5-Biscarboxamide (BUBA) : Easily Accessible C2-Symmetric Monomers for the Construction of Reversible and Chirally Amplified Helical Assemblies.”
Yan Li, Ludovic Dubreucq, Bruno G. Alvarenga, Matthieu Raynal,* and Laurent Bouteiller
Chem. Eur. J., 2019, 25, 10650-10661.
[P35] : “Experimental and computational diagnosis of the fluxional nature of a benzene-1,3,5-tricarboxamide-based hydrogen-bonded dimer.”
Matthieu Raynal,* Yan Li, Claire Troufflard, Cédric Przybylski, Geoffrey Gontard, Thomas Maistriaux, Julien Idé, Roberto Lazzaroni, Laurent Bouteiller, and Patrick Brocorens*
Phys. Chem. Chem. Phys., 2021, 23, 5207-5221.
(3) Authoritative and critical reviews and books
Biological homochirality. As a consequence of our interest in the use of circularly-polarized light as a chiral inducer for controlling the handedness of the aforementioned helical catalysts, we gained deep interest in the larger field of understanding the origin of the biological homochirality (i.e. the single chirality of biological molecules in terrestrial biology). Our critical literature overview has been published in Chem. Soc. Rev.[P39]
Supramolecular catalysis. Hydrogen-bonded helical catalysts are part of a large discipline dealing with the use of non-covalent interactions to drive catalytic reactions. The field is truly fascinating with a plethora of various approaches as reviewed in Chem. Soc. Rev.[P11],[P12] and book chapters.[BC1]-[BC4] P. van Leeuwen and I recently edited a book on this topic structured around 40 small chapters written by the specialists of the domain.[EB1]
Related publications :
[P11] : “Supramolecular catalysis. Part 1 : non-covalent interactions as a tool for building and modifying homogeneous catalysts.”
Matthieu Raynal,* Pablo Ballester, Anton Vidal-Ferran, and Piet W. N. M. van Leeuwen
Chem. Soc. Rev., 2014, 43, 1660-1733.
[P12] : “Supramolecular catalysis. Part 2 : artificial enzyme mimics.”
Matthieu Raynal,* Pablo Ballester, Anton Vidal-Ferran, and Piet W. N. M. van Leeuwen
Chem. Soc. Rev., 2014, 43, 1734-1787.
[BC1] : “Supramolecular Chemistry in Water”, Piet W. N. M. van Leeuwen, Matthieu Raynal pp 525-561 in first Edition, Stefan Kubik, Ed., 2019, Wiley-VCH Verlag, GmbH& Co. KGaA
[EB1] : “Supramolecular Catalysis : New Directions and Developments” co-edited with P. W. N. M. van Leeuwen, 2022 Wiley‐VCH GmbH, Print ISBN:9783527349029, Online ISBN:9783527832033, doi:10.1002/9783527832033
[BC2] : “Supramolecular Catalysis : An Introduction”, M. Raynal, P. W. N. M. van Leeuwen, in Supramolecular Catalysis : New Directions and Developments, First Edition, Eds. P. W. N. M. van Leeuwen and M. Raynal, WILEY-VCH GmbH, 12/2021, https://onlinelibrary.wiley.com/doi/10.1002/9783527832033.fmatter
[P39] : “Possible Chemical and Physical Scenarios Towards Biological Homochirality”
Quentin Sallembien,* Laurent Bouteiller, Jeanne Crassous,* Matthieu Raynal*
Chem. Soc. Rev., 2022, 51, 3436-3476.
[BC4] : “Supramolecular Regulation in Enantioselective Catalysis”, M. Raynal, A. Vidal-Ferran, in Topics in Enantioselective Catalysis : Recent Achievements and Future Challenges, Ed. A. Marinetti, World Scientific, 08/2022,