## Abstract A method is proposed which automatically compares experimental and predicted ^1^H chemical shifts, integrals and scalar couplings and allows the structure on which the predictions are based to be confirmed or refuted. The method is comparatively insensitive to the variable presence of l
Towards the automatic analysis of 1H NMR spectra: Part 5. Confirmation of chemical structure with flow-NMR
β Scribed by Lee Griffiths
- Publisher
- John Wiley and Sons
- Year
- 2005
- Tongue
- English
- Weight
- 103 KB
- Volume
- 44
- Category
- Article
- ISSN
- 0749-1581
- DOI
- 10.1002/mrc.1724
No coin nor oath required. For personal study only.
β¦ Synopsis
Abstract
A shift comparison procedure, which allows the use of flow spectra in automatic structure confirmation, is described. The effect of imperfect proton scaling at the analysis stage, loss of solute resonances under large solvent signals and the intermittent detection of labile protons are considered. The derivation of a suitable threshold acceptance criterion in the absence of explicit knowledge of spectral prediction reliability is also discussed.
The methodology yielded approximately 10β15% incorrect structure confirmation, but the exact number depends on the reliability of spectral prediction and the number of incorrect but closely related structures postulated. Copyright Β© 2006 John Wiley & Sons, Ltd.
π SIMILAR VOLUMES
A method of comparing predicted and experimental chemical shifts was used to confirm or refute postulated structures. 1H NMR spectra returned all true positives with a false positive rate of 4%. When an analogous procedure was adopted for 13C NMR spectra, the false positive rate dropped to 1%, where
## Abstract FlowβNMR allows more rapid and convenient acquisition of NMR spectra. Its main application area has therefore been in multiple parallel synthesis or combinatorial chemistry. At the same time, there is a significant need to automate the analysis of the resultant spectra. However, flowβNM
## Abstract A method was developed for the extraction of accurate NMR integrals, even where partially convoluted with other solute or solvent resonances, and then automatically allocating these to multiplets. The method yields an overall error of 7%, an assessment which includes a statistical distr
## Abstract A reliable method of automatically assigning oneβdimensional proton spectra is described. The method relies on the alignment of the proton spectrum with an associated heteronuclear singleβquantum coherence (HSQC) spectrum, transferring the stoichiometry and couplings to the HSQC. The HS