Wide-scope enantioselective voltammetry: inherently chiral selectors meet chiral probes representative of different stereogenic elements

Abstract. Enantioselective electroanalysis is an attractive target of high potential interest. Of course enantiodiscrimination can only be achieved with the electron transfer process taking place at a chiral electrode|medium interphase. In this frame, remarkable performances have been recently observed employing selectors endowed with "inherent chirality", i.e. in which chirality and key functional properties originate from the same element.[1,2] Successful chiral voltammetry tests have been obtained (a) on chiral electrode surfaces based on inherently chiral, electroactive heterocycle-based oligomers, including cyclic ones [3-6] and (b) on achiral electrodes in inherently chiral ionic liquids or achiral ionic liquids with inherently chiral additives [7,8]. An attractive feature of the above approach is its general validity. We have observed that a given inherently chiral selector can discriminate the enantiomers of even very different chiral probes (and, symmetrically, the enantiomers of a given probe can be discriminated by different inherently chiral selectors). Such observations now include cases representative of four different classes of stereogenic elements, corresponding to stereocentre-based chirality, axial chirality, helical chirality and planar chirality. A selection of examples will be presented and discussed. The support of Fondazione Cariplo/Regione Lombardia "Avviso congiunto per l’incremento dell’attrattività del sistema di ricerca lombardo e della competitività dei ricercatori candidati su strumenti ERC - edizione 2016” (Project 2016-0923) is gratefully acknowledged. [1] Curr. Opin. Electrochem. 8 (2018) 60-72; [2] Curr. Opin. Electrochem. 7 (2018) 188-199; [3] Angew. Chem. Int. Ed. 53 (2014) 2623-2627; [4] Chem-Eur. J. 20 (2014) 15261-15634; [5] Chem. Sci. 6 (2015) 1706-1711; [6] Chem-Eur. J. 22 (2016) 10839-10847; [7] Angew. Chem. Int. Ed. 56 (2017) 2079 –2082; [8] Electrochem. Comm. 89 (2018) 57-61.