Functionalized Chiral Bambusurils: Synthesis and Host-Guest Interactions with Chiral Carboxylates


                          Jan Sokolov, Adam Štefek, Vladimír Šindelář* ^


  Department of Chemistry and RECETOX, Faculty of Science, Masaryk University, Kamenice 5, 625 00
                                       Brno, Czech Republic.

                                  E-mail: sindelar@chemi.muni.cz


Bambusurils are a group of macrocyclic compounds that features notable anion recognition
properties.^1 Bambusurils can bind inorganic anions as well as carboxylates, sulfonates or organic
phosphates.^2-4 Recently we started investigating enantioselective binding of chiral carboxylates
by chiral bambusuril derivatives.^5 Hereby we report synthesis and supramolecular behavior of two
new representatives of chiral bambusuril macrocycles bearing ester groups (Figure 1) that are
suitable for further modifications.^6 Supramolecular properties of the new macrocycles were studied
by means of NMR. New bambusurils exhibit enantioselective binding of chiral carboxylate anions.
Comparison of the new macrocycle with a previously reported one shows that introduction of the
substituents has significant impact on the enantioselectivity. The results also indicate that
selectivity towards structurally different carboxylates is governed by bulkiness of the
substituents that surround bambusuril portals. Lastly, we would like to show the application of the
previously reported chiral bambusuril as chiral solvating agent.

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Figure 1. Structures of new chiral bambusuril macrocycles.







References

^1 T. Lizal, and V. Sindelar, Isr. J. Chem. 2018, 58 (3-4), 326–333.

^2 V. Havel and V. Sindelar, ChemPlusChem 2015, 80 (11), 1601–1606.

^3 V. Havel, V. Sindelar, M. Necas, and A. E. Kaifer, Chem Commun 2014, 50 (11), 1372–1374.

^4 T. Fiala and V. Sindelar, Supramol. Chem. 2016, 28 (9-10), 810–816.

^5 J. Sokolov, and V. Šindelář, Chem. Eur. J. 2018, 24 (58), 15482–15485.

^6 J. Sokolov, A. Štefek and V. Šindelář, ChemPlusChem 2020, 85 (6), 1307–1314.