An enantioselective NMR shift reagent for cationic aromatics.
[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.
Dignam
Catherine F
CF
Department of Chemistry, Bates College, Lewiston, Maine 04240, USA.
Richards
Christopher J
CJ
Zopf
Jason J
JJ
Wacker
Lee S
LS
Wenzel
Thomas J
TJ
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
D002412:Cations; D003505:Cyclodextrins; D028581:Lanthanoid Series Elements; D047028:Macrocyclic Compounds; D011108:Polymers; D012997:Solvents; C494074:calix(4)resorcarene; D047250:Calixarenes; D011392:Proline