The 1H and 13C NMR chemical shifts of Strychnos alkaloids revisited at the DFT level

• Published in: Magnetic resonance in chemistry Vol. 58; no. 6; pp. 532 - 539
• Main Authors: Semenov, Valentin A., Samultsev, Dmitry O., Krivdin, Leonid B.
• Format: Journal Article
• Language: English
• Published: Bognor Regis Wiley Subscription Services, Inc 01-06-2020
• Subjects: 1H and 13C NMR; Alkaloids; Density functional theory; DFT; Mathematical analysis; NMR; Nuclear magnetic resonance; Strychnine; Strychnos alkaloids
• ISSN: 0749-1581; 1097-458X
• DOI: 10.1002/mrc.4948

The density functional theory calculation of 1H and 13C NMR chemical shifts in a series of ten 10 classically known Strychnos alkaloids with a strychnine skeleton was performed at the PBE0/pcSseg‐2//pcseg‐2 level. It was found that calculated 1H and 13C NMR chemical shifts provided a markedly good correlation with experiment characterized by a mean absolute error of 0.08 ppm in the range of 7 ppm for protons and 1.67 ppm in the range of 150 ppm for carbons, so that a mean absolute percentage error was as small as ~1% in both cases.
The DFT calculation of 1H and 13C NMR chemical shifts in a series of 10 classically known Strychnos alkaloids with a strychnine carbon skeleton was performed at the PBE0/pcSseg‐2//pcseg‐2 level. It was found that calculated 1H and 13C NMR chemical shifts provided a markedly good correlation with experiment characterized by a mean absolute error of 0.08 ppm in the range of 7 ppm for protons and 1.67 ppm in the range of 150 ppm for carbons.