Supramolecular helical catalysts : chirality induction and beyond

Résumé :

Helices are commonly formed by symmetry breaking operating during the bottom-up assembly of small molecules or monomers and their sense of rotation can be controlled by various methods. Important progress has been made in controlling the chiral and structural properties of supramolecular discrete assemblies and polymers.[1] Benzene-1,3,5- tricarboxamide[2] (BTA) are ubiquitous synthons for the preparation of hydrogen-bonded helices but it remains to be demonstrated how a given macroscopic property, notably related to chirality (e.g. chiroptical, magnetic, catalytic), can be affected by tuning the structure of these supramolecular polymers or copolymers. We demonstrated that the supramolecular chirality of BTA assemblies can be transferred to intrinsically achiral metal centres (Rh, Cu) located at their periphery.[3] How the selectivity of a catalytic reaction of reference can be affected by the nature of the monomers, the presence of metal centres, and the addition of achiral additives will be particularly discussed.[4] Not only a fine tuning of the chirality of the supramolecular assemblies but also a proper control of their dynamicity is key to address important challenges. We recently disclose the possibility to select one major (70%-79%) amongst four possible stereoisomers of an amino alcohol by applying the supramolecular helical catalyst in either concomitant (with no inversion of catalyst handedness) or sequential (with inversion of catalyst handedness) hydrosilylation and hydroamination reactions [5].

References :

[1] Yashima E. et al. Chem. Rev., 2016, 116, 13752.
[2] Cantekin S. et al. Chem. Soc. Rev., 2012, 41, 6125.
[3] Desmarchelier A. et al. J. Am. Chem. Soc., 2016, 138, 4908.
[4] (a) Li Y. et al. J. Am. Chem Soc., 2020, 142, 5676. (b) Martínez-Aguirre M. A. et al. Angew. Chem. Int. Ed., 2021, 60, 4183. (c) Hammoud A. et al. Chem. Eur. J., 2023, e202300189. (d) Kong H. et al. ChemistryEurope, 2023, 1, e202300027.
[5] Chen, R. et al. Nature Commun., 2024, 15, 4116

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Contact : adrien.quintard@univ-grenoble-alpes.fr