Two single-enantiomer amidophosphoesters: a database study on the chirality of (O) 2 P(O)(N)-based structures

• Published in: Acta crystallographica. Section C, Structural chemistry Structural chemistry, 2019-01, Vol.75 (Pt 1), p.77-84
• Main Authors: Sabbaghi, Fahimeh, Pourayoubi, Mehrdad, Nečas, Marek, Damodaran, Krishnan
• Format: Article
• Language: English
• ISSN: 2053-2296; 2053-2296
• DOI: 10.1107/S205322961801673X

The crystal structures of two single-enantiomer amidophosphoesters with an (O) P(O)(N) skeleton, i.e. diphenyl [(R)-(+)-α-methylbenzylamido]phosphate, (I), and diphenyl [(S)-(-)-α-methylbenzylamido]phosphate, (II), both C H NO P, are reported. In both structures, chiral one-dimensional hydrogen-bonded architectures, along [010], are mediated by N-H...OP interactions. The statistically identical assemblies include the noncentrosymmetric graph-set motif C(4) and the compounds crystallize in the chiral space group P2 . As a result of synergistic co-operation from C-H...O interactions, a two-dimensional superstructure is built including a noncentrosymmetric R (22) hydrogen-bonded motif. A Cambridge Structural Database survey was performed on (O) P(O)(N)-based structures in order to review the frequency of space groups observed in this family of compounds; the hydrogen-bond motifs in structures with chiral space groups and the types of groups inducing chirality are discussed. The J (X = H or C) coupling constants from the NMR spectra of (I) and (II) have been studied. In each compound, the two diastereotopic C H O groups are different, which is reflected in the different chemical shifts and some coupling constants.