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Enantiodifferentiation of α‐hydroxyalkanephosphonic acids in 31 P NMR with application of α‐cyclodextrin as chiral discriminating agent
Author(s) -
Rudzińska Ewa,
Dziȩdzioła Gabriela,
Berlicki Łukasz,
Kafarski Paweł
Publication year - 2010
Publication title -
chirality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.43
H-Index - 77
eISSN - 1520-636X
pISSN - 0899-0042
DOI - 10.1002/chir.20707
Subject(s) - chemistry , enantiomer , cyclodextrin , reagent , chemical shift , nmr spectra database , proton nmr , enantiomeric excess , spectral line , computational chemistry , stereochemistry , organic chemistry , enantioselective synthesis , catalysis , physics , astronomy
α‐Cyclodextrin was shown to be convenient chemical shift reagent for determination of the enantiomeric composition of α‐hydroxyphosphonic acids by means of 31 P NMR. The developed methodology appeared to be reliable, repetitive, easy to perform and simple for interpretation. Enantiomeric discrimination in the 31 P NMR spectra for 12 of 13 studied hydroxyphosphonates was achieved, with baseline separation of resonances obtained for eight compounds. In those cases, the chemical nonequivalence values ranged from 0.069 to 0.313 ppm. The studies showed that enantioselectivity is strongly influenced by the solution pD and the optimal condition was found at pD 2 or 10 depending on the guest structure. On the basis of the ROESY spectra the complexation modes of selected hydroxyphosphonates with α‐cyclodextrin was postulated. Chirality 2010. © 2009 Wiley‐Liss, Inc.