title: An enantioselective NMR shift reagent for cationic aromatics.
abstract: [structure: see text] The water-soluble tetra l-prolinylmethyl derivative of a tetrasulfonated calix[4]resorcarene is an effective chiral NMR solvating agent for compounds with bicyclic aromatic or indole rings. Complexation of bicyclic substrates with the calix[4]resorcarene is likely promoted by hydrophobic effects. The bicyclic substrates have larger association constants with the calix[4]resorcarene than similar phenyl-containing compounds. Substantial enantiomeric discrimination is observed for several resonances in the (1)H NMR spectra of these substrates.
authors.affiliation: Department of Chemistry, Bates College, Lewiston, Maine 04240, USA.
authors.forename: Catherine F
authors.initials: CF
authors.lastname: Dignam
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Richards
authors.forename: Jason J
authors.initials: JJ
authors.lastname: Zopf
authors.forename: Lee S
authors.initials: LS
authors.lastname: Wacker
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Wenzel
mesh_terms: D047250:Calixarenes / Q000737:chemistry; D002412:Cations; D003505:Cyclodextrins / Q000737:chemistry*; D028581:Lanthanoid Series Elements / Q000737:chemistry; D047028:Macrocyclic Compounds / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D011108:Polymers / Q000737:chemistry; D011392:Proline / Q000031:analogs & derivatives / Q000737:chemistry; D012997:Solvents; D013237:Stereoisomerism
chemical_list: D002412:Cations; D003505:Cyclodextrins; D028581:Lanthanoid Series Elements; D047028:Macrocyclic Compounds; D011108:Polymers; D012997:Solvents; C494074:calix(4)resorcarene; D047250:Calixarenes; D011392:Proline