Biheteroaromatic Scaffolds to Design Unconventional Chiral Ionic Liquids

Chiral Ionic Liquids (CILs) constitute a class of solvents which got an increasing importance in the last ten years. They are used as solvents in asymmetric synthesis and in stereoselective polymerization, as chiral phases for gas chromatography, as chiral shift reagents in NMR spectroscopy and, in some cases, to generate cholesteric liquid crystals. Most of known CILs, are onium salts characterized by chiral substituents having one or several stereocenters. The aim of the research is to design, synthesize, characterize and test in electrochemical oxo-reduction processes a new family of non-conventional CILs in which the stereogenic element (a stereogenic axis) coincides with the function responsible for the IL properties. Using the successful strategy recently employed for designing "inherently chiral" oligotiophenes,1 some "inherently chiral" CILs have been prepared based on 1,1'-, 2,2'-bisimidazolium and 3,3'-bipyridinium atropisomeric scaffolds.Structural characterization by single-crystal X-ray analysis, HPLC characterizations, the evalution of configurationalstability and elettrochemical behaviour are described. Some alkylation reactions have been performed and the salts obtained have been characterized.