The role of two-dimensional nuclear magnetic resonance spectroscopy in computer-enhanced structure elucidation

Fully Automated Structure ElucidationA Spectroscopist's Dream Comes True

“…It consists of subspectrum, connectivity matrix, and the HOSE code for all heavy atoms. 13 C-NMR parameters (chemical shift, multiplicity, intensity, and rms-values for chemical shifts) are stored for each carbon atom of every substructure. The rms-values were derived from sets of equivalent substructures in the SpecInfo data base.…”

“…All hits of the subspectra search are starting nodes SN of a graph. The overlap of a matching substructure (numbers [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] with the starting structure leads to an intermediate substructure, depicted by the nodes of the graph (letters A-S). A particular search path is terminated if the spectrum resulting from the overlap is not completely contained in the query spectrum (open circles).…”

Computer‐assisted structure elucidation of natural products with limited 2D NMR data: application of the StrucEluc system

“…The examples reported by Munk and co-workers 20,21 demonstrate that the allowed distance between the coupled nuclei can be defined by the user. However, the CASE system described here has no ability to detect non-standard correlations.…”

“…At present, there are approximately 20 applications available that can be applied to spectral data analysis to elucidate a molecular structure. In recent years the following applications have been reported in the literature: RASTR (STREC), 18 X-PERT, 19 SESAMI, 20,21 CHEMICS, 22 SpecSolv, 23 CISOC-SES 24 /NMR-SAMS, 25 COCON, 26,27 LSD, 28 LUCY, 29 SENECA 30 and others. For the modern CASE systems, 1D 13 C, 1 H and 2D NMR spectra, COSY, HMQC/HSQC and HMBC and the molecular formula defined on the basis of high-resolution mass spectrometry (HRMS) usually serve as the raw data inputs.…”

Automated Interpretation of NMR Spectra for Small Organic Molecules in Solution

“…At that time, CASE was driven by chemical shift interpretation through data base search, even though the idea of constraining structure assembly by 2-D COSY and HMBC data had already emerged. 26 Correlation-driven structure generation appeared as a new paradigm for CASE systems and was first reported in 1991 in the paper entitled 'Logical for Structure Determination' that presented the basics of the LSD software. 27 A chemist considers that the task of structure elucidation has reached its end when all bonds have been set between the atoms (2-D structure) and when the relative configuration of asymmetric centers have been determined (relative 3-D structure), and, for enantiomerically pure compounds, when absolute configurations are known (absolute 3-D structure).…”