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

Abstract

The crystal structures of two single-enantiomer amidophosphoesters with an (O) 2 P(O)(N) skeleton, i.e. diphenyl [(R)-(+)--methylbenzylamido]phosphate, (I), and diphenyl [(S)-(À)--methylbenzylamido]phosphate, (II), both C 20 H 20 -NO 3 P, are reported. In both structures, chiral one-dimensional hydrogenbonded architectures, along [010], are mediated by N-HÁ Á ÁOP interactions. The statistically identical assemblies include the noncentrosymmetric graph-set motif C(4) and the compounds crystallize in the chiral space group P2 1 . As a result of synergistic co-operation from C-HÁ Á ÁO interactions, a two-dimensional superstructure is built including a noncentrosymmetric R 4 4 (22) hydrogenbonded motif. A Cambridge Structural Database survey was performed on (O) 2 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 2,3 J X-P (X = H or C) coupling constants from the NMR spectra of (I) and (II) have been studied. In each compound, the two diastereotopic C 6 H 5 O groups are different, which is reflected in the different chemical shifts and some coupling constants.

Conformational flexibility in amidophosphoesters: a CSD analysis completed with two new crystal structures of (C6H5O)2P(O)X [X = NHC7H13 and N(CH2C6H5)2]

“…The P O bond lengths [1.4645 (18) Å for (I) and 1.4578 (10) Å for (II)] are comparable to those in analogous compounds (Sabbaghi et al, 2019) and are slightly longer than the normal P O double-bond length (1.45 Å ; Corbridge, 1995). The P-N bond lengths [1.607 (2) Å for (I) and 1.6232 (11) Å for (II)] are standard for structures with an (O) 2 P(O)(N) skeleton (Sabbaghi et al, 2019) and are smaller than a typical P-N single-bond length (Corbridge, 1995).…”

The synergistic co-operation of N—H...O=P hydrogen bonds and C—H...OX weak intermolecular interactions (X is =P or —C) in the (CH3O)2P(O)(NH–NHC6F5) amidophosphoester: a combined X-ray crystallographic and theoretical study

“…The P O bond lengths are within the standard range for analogous compounds (Keikha et al, 2017) and are longer than the normal P O bond length (1.45 Å ; Corbridge, 1995). The P-N bond lengths are standard for structures with an (O) 2 (N)P(O) skeleton (Sabbaghi et al, 2019) and less than a typically average P-N bond length (Corbridge, 1995).…”

Structural differences/similarities of diastereotopic groups in three new chiral phosphoramides

“…Chiral phosphoramides are well known for some biochemical properties, typically in the formulation of different classes of drugs (Warren et al, 2016), and offer a promising perspective toward developing diverse systems, such as enantioselective catalysts (Liao et al, 2019) and chiral adsorbent polymers (Ahmadabad et al, 2019). Some subclasses of phosphoramides, for example, amidophosphoesters and phosphoric triamides, were studied with respect to chirality and have attracted much attention for further studies (Sabbaghi et al, 2019;Ariani et al, 2017).…”

“…The P O group in a phosphoramide shows a good hydrogen-bond acceptor capability (Eghbali Toularoud et al, 2018), which is a suitable property for applications related to sorption; thus, chiral phosphoramide-based polymers were manufactured and used for the separation of single enantiomers from their racemic mixtures (Ahmadabad et al, 2019). Recently, we have reported the first enantiomeric pair for both (O) 2 P(O)(N)-based (Sabbaghi et al, 2019) and C(O)NH-P(O)(N) 2 -based structures (Eghbali Toularoud et al, 2018), and some single-enantiomer compounds belonging to different families, including both small molecules and macromolecules (Ariani et al, 2017;Ahmadabad et al, 2019).…”