Appropriately substituted quinolines can exist as atropisomers. Canonical atropisomers are stereoisomers that arise from hindered rotation around a σ-bond . Like stereoisomers with point chirality, atropisomers can bind macromolecular targets with distinct kinetics as well as different affinities . Atropisomeric quinolines and quinoline-like heterocycles are well known. They are found in pharmaceuticals such as Sotorasib, a first-in-class mutant KRAS G12C inhibitor , as well as novel HIV-I integrase inhibitors . Atropisomeric quinolines also serve as the molecular framework for catalysts with widespread use in organic synthesis and process research, such as QUINAP . Although many macrocyclic peptide natural products contain unusual structural isomers, sometimes called atropisomers , non-canonical atropisomers , or ansamers , that result from threaded-loop or knot-like structures , true canonical atropisomers are also important constituents of this class of compounds, such as the famous case of the cyclic glycopeptide vancomycin . Peptides or cyclic peptides containing atropoisomeric quinolines would add a sophisticated layer of stereochemical complexity to macrocyclic peptide libraries.