TY - JOUR
T1 - Efficient NMR enantiodiscrimination of bridge fluorinated paracyclophanes using lanthanide tris β-diketonate complexes
AU - Roche, Alex J.
AU - Rabinowitz, Sheryl A.
AU - Cox, Kasey A.
N1 - Funding Information:
We would like to thank Mr. Alexander A. Marchione (DuPont) for stimulating and productive discussions, and technical assistance in the presentation of spectra. The National Science Foundation is acknowledged for allowing the purchase of a Varian Mercury Plus Spectrometer and Agilent HPLC-MS system through instrumentation Grants ( NSF CHE-0116145 and NSF CHE-0541663 ). Contract/Grant sponsor for this study is National Science Foundation ( CHE-0116145 ) and National Science Foundation ( CHE-0541663 ).
PY - 2013/11/30
Y1 - 2013/11/30
N2 - A selection of amino-substituted 1,1,2,2,9,9,10,10 octafluoro[2.2] paracyclophanes were tested for enantiodiscrimination by 1H and 19F NMR spectroscopy via their interaction with different lanthanide tris β-diketonate chiral shift reagents. The amino-, and the pseudo-ortho di-amino substituted octafluoro[2.2]paracyclophanes, both of which exhibit planar chirality, revealed significant shifts and splittings of various 1H and 19F NMR signals upon the addition of the chiral shift reagents, which allowed the easy determination of the enantiomeric purity. When the chiral shift reagent was added to an inseparable mixture of the (chiral) pseudo-meta, and (achiral) pseudo-para diamino analogues, both the chiral and achiral molecules revealed NMR doubling. In the case of the achiral molecule, this NMR behavior is due to the meso nature of the pseudo-para species.
AB - A selection of amino-substituted 1,1,2,2,9,9,10,10 octafluoro[2.2] paracyclophanes were tested for enantiodiscrimination by 1H and 19F NMR spectroscopy via their interaction with different lanthanide tris β-diketonate chiral shift reagents. The amino-, and the pseudo-ortho di-amino substituted octafluoro[2.2]paracyclophanes, both of which exhibit planar chirality, revealed significant shifts and splittings of various 1H and 19F NMR signals upon the addition of the chiral shift reagents, which allowed the easy determination of the enantiomeric purity. When the chiral shift reagent was added to an inseparable mixture of the (chiral) pseudo-meta, and (achiral) pseudo-para diamino analogues, both the chiral and achiral molecules revealed NMR doubling. In the case of the achiral molecule, this NMR behavior is due to the meso nature of the pseudo-para species.
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U2 - 10.1016/j.tetasy.2013.09.024
DO - 10.1016/j.tetasy.2013.09.024
M3 - Article
AN - SCOPUS:84887624050
VL - 24
SP - 1382
EP - 1388
JO - Tetrahedron Asymmetry
JF - Tetrahedron Asymmetry
SN - 0957-4166
IS - 21-22
ER -