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Abstract We present a method to use long‐range CH coupling constants to derive the correct diastereoisomer from the molecular constitution of small molecules. A set of 792JCHand3JCHvalues collected from a single HSQMBC experiment on a sample of strychnine were used in the CASE‐3D (computer‐assisted 3D structure elucidation) protocol. In addition to the most commonly used3JCHcoupling constants, the subset of 322JCHvalues alone showed an excellent degree of configuration selection. The study is mainly based on comparison of DFT‐calculated2,3JCHvalues with experimental ones, critical for the case of2JCH. But the configuration selection also works well using3JCHvalues predicted from a semi‐empirical Karplus‐based equation limited to H−C−C−C fragments. The robustness, shown using strychnine as a proof of concept, makes theJ‐based CASE‐3D analysis a viable option for the application in fields such as peptide and carbohydrate research, organic synthesis, natural‐product identification and analysis, as well as medicinal chemistry.
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J ‐modulated 19 F‐ and 1 H‐detected dual‐optimized inverted 1 J CC 1,n‐ADEQUATE: A universal ADEQUATE experiment
Abstract The recently reported19F‐detected dual‐optimized inverted1JCC1,n‐ADEQUATE experiment and the previously reported1H‐detected version have been modified to incorporateJ‐modulation, making it feasible to acquire all 1,1‐ and 1,n‐ADEQUATE correlations as well as1JCCandnJCChomonuclear scalar couplings in a single experiment. The experiments are demonstrated usingN,N‐dimethylamino‐2,5,6‐trifluoro‐3,4‐phthalonitrile andN,N‐dimethylamino‐3,4‐phthalonitrile.
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- Award ID(s):
- 2116395
- PAR ID:
- 10531785
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- Magnetic Resonance in Chemistry
- Volume:
- 61
- Issue:
- 3
- ISSN:
- 0749-1581
- Page Range / eLocation ID:
- 169 to 179
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1002/mrc.5324
