DFT investigation of coupling constant anomalies in substituted β-lactams

Emily B Crull; Alexei V Buevich; Gary E Martin; Rohit Mahar; Bo Qu; Chris H Senanayake; Tadeusz F Molinski; R Thomas Williamson

doi:10.1002/mrc.5444

DFT investigation of coupling constant anomalies in substituted β-lactams

Magn Reson Chem. 2024 Aug;62(8):573-582. doi: 10.1002/mrc.5444. Epub 2024 Mar 21.

Authors

Emily B Crull¹, Alexei V Buevich², Gary E Martin³, Rohit Mahar^{4

5}, Bo Qu⁴, Chris H Senanayake⁴, Tadeusz F Molinski^{6

7}, R Thomas Williamson¹

Affiliations

¹ Department of Chemistry and Biochemistry, University of North Carolina Wilmington, Wilmington, North Carolina, USA.
² Analytical Research and Development, Merck & Co, Inc, Rahway, New Jersey, USA.
³ Department of Chemistry and Biochemistry, Seton Hall University, West Orange, New Jersey, USA.
⁴ TCG GreenChem, Inc, Ewing, New Jersey, USA.
⁵ Current address: Department of Chemistry, Hemvati Nandan Garhwal University, (A Central University), Srinagar, Uttarakhand, India.
⁶ Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California, USA.
⁷ Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, USA.

PMID: 38511664
DOI: 10.1002/mrc.5444

Abstract

β-lactams are a chemically diverse group of molecules with a wide range of biological activities. Having recently observed curious trends in ²J_HH coupling values in studies on this structural class, we sought to obtain a more comprehensive understanding of these diagnostic NMR parameters, specifically interrogating ¹J_CH, ²J_CH, and ²J_HH, to differentiate 3- and 4-monosubstituted β-lactams. Further investigation using computational chemistry methods was employed to explore the geometric and electronic origins for the observed and calculated differences between the two substitution patterns.

Keywords: Fermi contact; PIP‐HSQC; PIP‐HSQMBC; electrostatic potential; scalar couplings; β‐lactams.

Abstract

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