1. Determination of substitution sites in monosubstituted five-membered aromatic heterocycles
- Author
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Petra Kučerová, Roman Kubec, and Jan Schraml
- Subjects
chemistry.chemical_compound ,chemistry ,Stereochemistry ,Substitution (logic) ,Substituent ,Proton NMR ,General Materials Science ,General Chemistry ,Carbon-13 NMR ,Heteronuclear single quantum coherence spectroscopy ,Pyrrole - Abstract
Similar magnitudes of proton–proton couplings across three, four, and five bonds and proton–carbon couplings across two and three bonds combined with difficult to predict substituent effects make the results of an indiscriminate use of routine (COSY, HSQC, HMBC, etc.) techniques for substitution site determination in C-monosubstituted five-membered heteroaromatics suspect. As demonstrated on two examples of natural products, the use of 1,1-ADEQUATE leads to unambiguous substitution site determination lending thus further support to suggested inclusion of 1,1-ADEQUATE data into computer-assisted structure elucidation (CASE) protocols. Copyright © 2011 John Wiley & Sons, Ltd.
- Published
- 2011
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