Atroposelective Synthesis, Structure and Properties of a Novel Class of Axially Chiral <i>N</i>‐Aryl Quinolinium Salt
Jamie S. Sweet, Sundaram Rajkumar, Paul Dingwall, Peter C. Knipe
Abstract
Abstract Inspired by naturally occurring molecules containing atropisomeric N + ‐C axes, we have developed a novel synthetic approach to generate a library of axially chiral N ‐aryl quinolinium salts. Enantiopurities up to 93 % ee were obtained via a four‐step route from commercially available precursors. Axial stereochemistry was controlled through an enantioselective ring‐closing Buchwald–Hartwig coupling reaction. The structure and properties of the salts were examined by X‐ray crystallography, DFT, UV‐Vis, and fluorescence spectroscopy, revealing high rotational barriers and solvatochromic behaviour.
Topics & Concepts
ChemistryAtropisomerSolvatochromismArylAxial symmetryMoleculeEnantioselective synthesisSalt (chemistry)Axial chiralityCombinatorial chemistryRing (chemistry)StereochemistryComputational chemistryCrystallographyOrganic chemistryCatalysisAlkylStructural engineeringEngineeringAxial and Atropisomeric Chirality SynthesisMolecular spectroscopy and chiralityAlkaloids: synthesis and pharmacology