2025/03/11 by Anna Hruzíková, Vahid Barati, Aneta Ešnerová +4 · 1 voice
Agricultural and Biological Sciences · Chemistry · #Organophosphorus compounds synthesis #Phytochemistry and biological activities of Ficus species #Synthetic Organic Chemistry Methods
paper · pdf · doi:10.1002/chem.202500330
openalex publication_date 2025/03/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/05/21
Abstract Model phosphonamidates derived from 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) with molecular flexibility tuned by amino acid substituents were prepared as pairs of diastereoisomers (DSIs) differing in configuration on phosphorus atom. X‐ray diffraction (XRD) determined absolute configuration on phosphorus and revealed conformational flexibility of six‐membered oxa‐phospha‐cycle. Quantum‐chemical calculations combined with machine learning provided 2–4 representative conformers from each DSI present in solution. 31 P chemical shift of RS DSIs was higher compared to the SS ones. Calculated 31 P‐ 1 H as well as 31 P‐ 13 C J ‐couplings followed Karplus dependence of J ‐coupling values on dihedral angles between interacting nuclei, showing reasonable match with the literature data. The effect of molecular flexibility quantified by parameter nConf 20 on NMR parameters was significant, especially for residual dipolar couplings (RDCs), where Pearson correlation factor R decreased with increasing nConf 20 parameter.