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

2021 ◽  
Vol 77 (4) ◽  
pp. 186-196
Author(s):  
Negin Lal Zakaria ◽  
Mehrdad Pourayoubi ◽  
Mahsa Eghbali Toularoud ◽  
Michal Dušek ◽  
Eliska Skorepova

The crystal structures of two single-enantiomer amidophosphoesters with an (O)2P(O)(N) skeleton and one single-enantiomer phosphoric triamide with an (N)2P(O)(N) skeleton were studied. The compounds are diphenyl [(R)-(+)-α-4-dimethylbenzylamido]phosphate, (I), and diphenyl [(S)-(−)-α-4-dimethylbenzylamido]phosphate, (II), both C21H22NO3P, and N-(2,6-difluorobenzoyl)-N′,N′′-bis[(R)-(+)-α-ethylbenzyl]phosphoric triamide, C25H28F2N3O2P, (III). The asymmetric units contain two amidophosphoester molecules for (I) and (II), and one phosphoric triamide molecule for (III). In the crystal structures of (I) and (II), molecules are assembled in a similar one-dimensional chiral ribbon architecture, but with almost a mirror-image relationship with respect to each other through N—H...O(P) and C—H...O(P) hydrogen bonds along [010]. In the crystal structure of (III), the chiral tape architecture along [100] is mediated by N—H...O(P) and N—H...O(C) hydrogen bonds, and the tapes are connected into slabs by C—H...O interactions (along the ab plane). The differences/similarities of the two diastereotopic phenoxy groups in (I)/(II) and the two chiral amine fragments in (III) were studied on the grounds of geometry, conformation and contribution to the crystal packing, as well as 1H and 13C signals in a solution NMR study.

2015 ◽  
Vol 71 (11) ◽  
pp. 1388-1391
Author(s):  
Vinola Z. Rodrigues ◽  
C. P. Preema ◽  
S. Naveen ◽  
N. K. Lokanath ◽  
P. A. Suchetan

Crystal structures of twoN-(aryl)arylsulfonamides, namely, 4-methoxy-N-(4-methylphenyl)benzenesulfonamide, C14H15NO3S, (I), andN-(4-fluorophenyl)-4-methoxybenzenesulfonamide, C13H12FNO3S, (II), were determined and analyzed. In (I), the benzenesulfonamide ring is disordered over two orientations, in a 0.516 (7):0.484 (7) ratio, which are inclined to each other at 28.0 (1)°. In (I), the major component of the sulfonyl benzene ring and the aniline ring form a dihedral angle of 63.36 (19)°, while in (II), the planes of the two benzene rings form a dihedral angle of 44.26 (13)°. In the crystal structure of (I), N—H...O hydrogen bonds form infiniteC(4) chains extended in [010], and intermolecular C—H...πarylinteractions link these chains into layers parallel to theabplane. The crystal structure of (II) features N—H...O hydrogen bonds forming infinite one dimensionalC(4) chains along [001]. Further, a pair of C—H...O intermolecular interactions consolidate the crystal packing of (II) into a three-dimensional supramolecular architecture.


Author(s):  
Wojciech Nitek ◽  
Agnieszka Kania ◽  
Henryk Marona ◽  
Anna M. Waszkielewicz ◽  
Ewa Żesławska

The aroxyalkylaminoalcohol derivatives are a group of compounds known for their pharmacological action. The crystal structures of four new xylenoxyaminoalcohol derivatives having anticonvulsant activity are reported, namely, 2-{[2-(2,6-dimethylphenoxy)ethyl]amino}-1-phenylethan-1-ol, C18H23NO2, 1, the salt N-[2-(2,6-dimethylphenoxy)ethyl]-1-hydroxy-1-phenylethan-2-aminium 3-hydroxybenzoate, C18H24NO2 +·C7H5O3 −, 2, and two polymorphs of the salt (R)-N-[2-(2,6-dimethylphenoxy)ethyl]-1-hydroxy-1-phenylethan-2-aminium chloride, C18H24NO2 +·Cl−, 3 and 3p. Both polymorphs crystallize in the space group P21212 and each has two cations and two anions in the asymmetric unit (Z′ = 2). The molecules in the polymorphs show differences in their molecular conformations and intermolecular interactions. The crystal packing of neutral 1 is dominated by intermolecular O—H...N hydrogen bonds, resulting in the formation of one-dimensional chains. In the crystal structures of the salt forms (2, 3 and 3p), each protonated N atom is engaged in a charge-assisted hydrogen bond with the corresponding anion. The protonation of the N atom also influences the conformation of the molecular linker between the two aromatic rings and changes the orientation of the rings. The crystal packing of the salt forms is dominated by intermolecular O—H...O hydrogen bonds, resulting in the creation of chains and rings. Structural studies have been enriched by the calculation of Hirshfeld surfaces and the corresponding fingerprint plots.


2014 ◽  
Vol 70 (10) ◽  
pp. 998-1002 ◽  
Author(s):  
Mehrdad Pourayoubi ◽  
Atekeh Tarahhomi ◽  
Arnold L. Rheingold ◽  
James A. Golen

InN,N,N′,N′-tetraethyl-N′′-(4-fluorobenzoyl)phosphoric triamide, C15H25FN3O2P, (I), andN-(2,6-difluorobenzoyl)-N′,N′′-bis(4-methylpiperidin-1-yl)phosphoric triamide, C19H28F2N3O2P, (II), the C—N—C angle at each tertiary N atom is significantly smaller than the two P—N—C angles. For the other new structure,N,N′-dicyclohexyl-N′′-(2-fluorobenzoyl)-N,N′-dimethylphosphoric triamide, C21H33FN3O2P, (III), one C—N—C angle [117.08 (12)°] has a greater value than the related P—N—C angle [115.59 (9)°] at the same N atom. Furthermore, for most of the analogous structures with a [C(=O)NH]P(=O)[N(C)(C)]2skeleton deposited in the Cambridge Structural Database [CSD; Allen (2002).Acta Cryst.B58, 380–388], the C—N—C angle is significantly smaller than the two P—N—C angles; exceptions were found for four structures with theN-methylcyclohexylamide substituent, similar to (III), one structure with the seven-membered cyclic amide azepan-1-yl substituent and one structure with anN-methylbenzylamide substituent. The asymmetric units of (I), (II) and (III) contain one molecule, and in the crystal structures, adjacent molecules are linkedviapairs of N—H...O=P hydrogen bonds to form dimers.


2018 ◽  
Vol 74 (5) ◽  
pp. 608-617 ◽  
Author(s):  
Mahsa Eghbali Toularoud ◽  
Mehrdad Pourayoubi ◽  
Michal Dušek ◽  
Václav Eigner ◽  
Krishnan Damodaran

The two single-enantiomer phosphoric triamides N-(2,6-difluorobenzoyl)-N′,N′′-bis[(S)-(−)-α-methylbenzyl]phosphoric triamide, [2,6-F2-C6H3C(O)NH][(S)-(−)-(C6H5)CH(CH3)NH]2P(O), denoted L-1, and N-(2,6-difluorobenzoyl)-N′,N′′-bis[(R)-(+)-α-methylbenzyl]phosphoric triamide, [2,6-F2-C6H3C(O)NH][(R)-(+)-(C6H5)CH(CH3)NH]2P(O), denoted D-1, both C23H24F2N3O2P, have been investigated. In their structures, chiral one-dimensional hydrogen-bonded architectures are formed along [100], mediated by relatively strong N—H...O(P) and N—H...O(C) hydrogen bonds. Both assemblies include the noncentrosymmetric graph-set motifs R 2 2(10), R 2 1(6) and C 2 2(8), and the compounds crystallize in the chiral space group P1. Due to the data collection of L-1 at 120 K and of D-1 at 95 K, the unit-cell dimensions and volume show a slight difference; the contraction in the volume of D-1 with respect to that in L-1 is about 0.3%. The asymmetric units of both structures consist of two independent phosphoric triamide molecules, with the main difference being seen in one of the torsion angles in the OPNHCH(CH3)(C6H5) part. The Hirshfeld surface maps of these levo and dextro isomers are very similar; however, they are near mirror images of each other. For both structures, the full fingerprint plot of each symmetry-independent molecule shows an almost asymmetric shape as a result of its different environment in the crystal packing. It is notable that NMR spectroscopy could distinguish between compounds L-1 and D-1 that have different relative stereocentres; however, the differences in chemical shifts between them were found to be about 0.02 to 0.001 ppm under calibrated temperature conditions. In each molecule, the two chiral parts are also different in NMR media, in which chemical shifts and P–H and P–C couplings have been studied.


2010 ◽  
Vol 65 (11) ◽  
pp. 1363-1371 ◽  
Author(s):  
Christoph Wölper ◽  
Alejandra Rodríguez-Gimeno ◽  
Katherine Chulvi Iborra ◽  
Peter G. Jones ◽  
Armand Blaschette

Co-crystallization of N-methyl-substituted ureas with di(organosulfonyl)amines, (RSO2)2NH, leads unpredictably to either molecular co-crystals or, via proton transfer, to uronium salts. As a sequel to former reports, this communication describes the formation and the crystal structures of the new ionic compounds 1,1-dimethyluronium di(4-fluorobenzenesulfonyl)amide (1, monoclinic, space group P21/c, Z´ = 1) and di(1-methylurea)hydrogen(I) di(4-fluorobenzenesulfonyl)amide (2, triclinic, P1̄, Z´ = 1); both salts were obtained from dichloromethane/petroleum ether. In the structure of 2, the urea moieties of the cationic homoconjugate are connected by a very short [O-H· · ·O]+ hydrogen bond [d(O· · ·O) = 244.6(2) pm, θ (O-H· · ·O)≈170°, bridging H atom asymmetrically disordered over two positions]. The O-protonation induces a specific elongation of the C-O bond lengths to 131.2(2) pm in 1 or 129.5(2) and 127.4(2) pm in 2, as compared to literature data of ca. 126 pm for the unprotonated ureas. Both crystal structures are dominated by conventional two- and threecentre hydrogen bonds, which involve the OH and all NH donors and give rise to one-dimensional cation-anion arrays. In particular, the ionic entities of 1 are alternatingly associated into simple chains propagated by glide-plane operations parallel to the c axis, whereas the donor-richer structure of 2 displays inversion symmetric dimers of formula units, which are further hydrogen-bonded into strands propagated by translation parallel to the a axis.


2013 ◽  
Vol 69 (12) ◽  
pp. 1549-1552 ◽  
Author(s):  
Vladimir V. Chernyshev ◽  
Sergey Y. Efimov ◽  
Ksenia A. Paseshnichenko ◽  
Andrey A. Shiryaev

The title salt, C8H12NO+·C7H10NO5−, crystallizes in two polymorphic modifications,viz.monoclinic (M) and orthorhombic (O). The crystal structures of both polymorphic modifications have been established from laboratory powder diffraction data. The crystal packing motifs in the two polymorphs are different, but the conformations of the anions are generally similar. InM, the anions are linked by pairs of hydrogen bonds of the N—H...O and O—H...O types into chains along theb-axis direction, and neighbouring molecules within the chain are related by the 21screw axis. The cations link these chainsviaO—H...O and N—H...O hydrogen bonds into layers parallel to (001). InO, the anions are linked by O—H...O hydrogen bonds into helices along [001], and neighbouring molecules within the helix are related by the 21screw axis. The neighbouring helical turns are linked by N—H...O hydrogen bonds. The cations link the helicesviaO—H...O and N—H...O hydrogen bonds, thus forming a three-dimensional network.


2018 ◽  
Vol 74 (8) ◽  
pp. 1111-1116 ◽  
Author(s):  
Shet M. Prakash ◽  
S. Naveen ◽  
N. K. Lokanath ◽  
P. A. Suchetan ◽  
Ismail Warad

2-Aminopyridine and citric acid mixed in 1:1 and 3:1 ratios in ethanol yielded crystals of two 2-aminopyridinium citrate salts, viz. C5H7N2 +·C6H7O7 − (I) (systematic name: 2-aminopyridin-1-ium 3-carboxy-2-carboxymethyl-2-hydroxypropanoate), and 3C5H7N2 +·C6H5O7 3− (II) [systematic name: tris(2-aminopyridin-1-ium) 2-hydroxypropane-1,2,3-tricarboxylate]. The supramolecular synthons present are analysed and their effect upon the crystal packing is presented in the context of crystal engineering. Salt I is formed by the protonation of the pyridine N atom and deprotonation of the central carboxylic group of citric acid, while in II all three carboxylic groups of the acid are deprotonated and the charges are compensated for by three 2-aminopyridinium cations. In both structures, a complex supramolecular three-dimensional architecture is formed. In I, the supramolecular aggregation results from Namino—H...Oacid, Oacid...H—Oacid, Oalcohol—H...Oacid, Namino—H...Oalcohol, Npy—H...Oalcohol and Car—H...Oacid interactions. The molecular conformation of the citrate ion (CA3−) in II is stabilized by an intramolecular Oalcohol—H...Oacid hydrogen bond that encloses an S(6) ring motif. The complex three-dimensional structure of II features Namino—H...Oacid, Npy—H...Oacid and several Car—H...Oacid hydrogen bonds. In the crystal of I, the common charge-assisted 2-aminopyridinium–carboxylate heterosynthon exhibited in many 2-aminopyridinium carboxylates is not observed, instead chains of N—H...O hydrogen bonds and hetero O—H...O dimers are formed. In the crystal of II, the 2-aminopyridinium–carboxylate heterosynthon is sustained, while hetero O—H...O dimers are not observed. The crystal structures of both salts display a variety of hydrogen bonds as almost all of the hydrogen-bond donors and acceptors present are involved in hydrogen bonding.


Author(s):  
K. Rajkumar ◽  
S. Sivakumar ◽  
R. Arulraj ◽  
Manpreet Kaur ◽  
Jerry P. Jasinski ◽  
...  

The syntheses and crystal structures of 3-(2-chloroethyl)-r-2,c-6-diphenylpiperidin-4-one, C19H20ClNO, (I), and 3-(2-chloroethyl)-r-2,c-6-bis(4-fluorophenyl)piperidin-4-one, C19H18ClF2NO, (II), are described. The piperidone ring adopts a chair conformation in (I), whereas a slightly distorted chair conformation is formed in (II). The dihedral angle between the mean plane of the phenyl rings is 59.1 (1)° in (I) and 76.1 (1)° in (II). The crystal packing features weak intermolecular N—H...O hydrogen bonds in each structure.


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