scholarly journals Optical Resolution of Dimethyl α-Hydroxy-Arylmethylphosphonates via Diastereomer Complex Formation Using Calcium Hydrogen O,O′-Dibenzoyl-(2R,3R)-Tartrate; X-Ray Analysis of the Complexes and Products

Symmetry ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 758 ◽  
Author(s):  
Zita Rádai ◽  
Péter Bagi ◽  
Mátyás Czugler ◽  
Konstantin Karaghiosoff ◽  
György Keglevich
Keyword(s):  
Complex Formation ◽  
Single Crystal ◽  
Tartaric Acid ◽  
Intermolecular Interactions ◽  
Calcium Salt ◽  
Enantiomeric Excess ◽  
Optical Resolution ◽  
X Ray

Two dimethyl α-hydroxy-arylmethylphosphonates (aryl = Ph and 2-MeOPh) were subjected to optical resolution via diastereomer complex formation applying the acidic calcium salt of O,O′-dibenzoyl-(2R,3R)-tartaric acid as the resolving agent. The dominating diastereomer complexes, whose structure was determined by single crystal X-ray measurements, were obtained in 96% and 68% diastereomer excess values, respectively. After decomposing the diastereomer formations by extraction, and after recrystallizations, the major enantiomer (S and R, respectively) of the α-hydroxyphosphonates were prepared in enantiomeric excess values of 96% and 68%, respectively. The stereostructure of the two α-hydroxy-arylmethylphosphonates was again established by X-ray measurements. Detailed study on the X-ray data allowed valuable conclusions on the nature of the coordination in the complexes (intermolecular interactions), and on the H-bonding.

Substituent and Solvent Effects on Intermolecular Interactions in Crystals of N-Acylhydrazone Derivatives: Single-Crystal X-ray, Solid-State NMR, and Computational Studies

2014 ◽  
Vol 14 (5) ◽  
pp. 2263-2281 ◽  
Author(s):  
Liliana Mazur ◽  
Katarzyna N. Jarzembska ◽  
Radosław Kamiński ◽  
Krzysztof Woźniak ◽  
Edyta Pindelska ◽  
...  
Keyword(s):  
Solid State ◽  
Single Crystal ◽  
Intermolecular Interactions ◽  
Solvent Effects ◽  
Solid State Nmr ◽  
Computational Studies ◽  
X Ray

Quantitative Analysis of Intermolecular Interactions in 3‐Cyano‐2‐Pyridones: Evaluation through Single Crystal X‐ray Diffraction and Density Functional Theory

2018 ◽  
Vol 3 (21) ◽  
pp. 5864-5873
Author(s):  
Sunil K. Rai ◽  
Tomasz Sierański ◽  
Shaziya Khanam ◽  
Krishnan Ravi Kumar ◽  
Balasubramanian Sridhar ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Quantitative Analysis ◽  
Single Crystal ◽  
Intermolecular Interactions ◽  
Density Functional ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray

Synthesis, growth, structure and characterization of molybdenum zinc thiourea complex crystals

2015 ◽  
Vol 71 (3) ◽  
pp. 285-292 ◽  
Author(s):  
M. Rajasekar ◽  
K. Muthu ◽  
A. Aditya Prasad ◽  
R. Agilandeshwari ◽  
SP Meenakshisundaram
Keyword(s):  
Single Crystal ◽  
Diffraction Analysis ◽  
Intermolecular Interactions ◽  
Crystal Packing ◽  
Second Harmonic ◽  
Morphological Changes ◽  
Strong Interactions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters

Single crystals of molybdenum-incorporated tris(thiourea)zinc(II) sulfate (MoZTS) are grown by the slow evaporation solution growth technique. Crystal composition as determined by single-crystal X-ray diffraction analysis reveals that it belongs to the orthorhombic system with space groupPca21and cell parametersa= 11.153 (2),b= 7.7691 (14),c= 15.408 (3) Å,V= 1335.14 (4) Å3andZ= 4. The surface morphological changes are studied by scanning electron microscopy. The vibrational patterns in FT–IR are used to identify the functional group and TGA/DTA (thermogravimetric analysis/differential thermal analysis) indicates the stability of the material. The structure and the crystallinity of the material were confirmed by powder X-ray diffraction analysis and the simulated X-ray diffraction (XRD) closely matches the experimental one with varied intensity patterns. The band gap energy is estimated using diffuse reflectance data by the application of the Kubelka–Munk algorithm. The relative second harmonic generation (SHG) efficiency measurements reveal that MoZTS has an efficiency comparable to that of tris(thiourea)zinc(II) sulfate (ZTS). Hirshfeld surfaces were derived using single-crystal X-ray diffraction data. Investigation of the intermolecular interactions and crystal packingviaHirshfeld surface analysis reveal that the close contacts are associated with strong interactions. Intermolecular interactions as revealed by the fingerprint plot and close packing could be the possible reasons for facile charge transfer leading to SHG activity.

scholarly journals (S)-Pramipexole and Its Enantiomer, Dexpramipexole: A New Chemoenzymatic Synthesis and Crystallographic Investigation of Key Enantiomeric Intermediates

Catalysts ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 941
Author(s):  
Samuele Ciceri ◽  
Patrizia Ferraboschi ◽  
Paride Grisenti ◽  
Shahrzad Reza Elahi ◽  
Carlo Castellano ◽  
...  
Keyword(s):  
Single Crystal ◽  
Enantiomeric Excess ◽  
Three Dimensional ◽  
Building Blocks ◽  
Chemoenzymatic Synthesis ◽  
Racemic Mixture ◽  
Candida Antarctica Lipase ◽  
Crystallographic Investigation ◽  
Reaction Conditions ◽  
X Ray

A new chemoenzymatic method has been developed for the synthesis of (S)- and (R)-N-(6-hydroxy-4,5,6,7-tetrahydrobenzo[d]thiazol-2-yl) acetamide, two key synthons for the preparation of (S)-pramipexole, an anti-Parkinson drug, and its enantiomer dexpramipexole, which is currently under investigation for the treatment of eosinophil-associated disorders. These two building blocks have been obtained in good yields and high enantiomeric excess (30% and >98% ee for the R-enantiomer, and 31% and >99% ee for the S- one) through a careful optimization of the reaction conditions, starting from the corresponding racemic mixture and using two consecutive irreversible transesterifications, catalyzed by Candida antarctica lipase type A. Single crystal X-ray analysis has been carried out to unambiguously define the stereochemistry of the two enantiomers, and to explore in depth their three-dimensional features.

Synthese neuer optisch aktiver Rh-Komplexe: Die Kristallstruktur von [(5S)-3,4-Bis(diphenylphosphino)-5-menthoxy-2(5H)-furanon](1,5-cyclooctadien)rhodium-hexafluorophosphat / Synthesis of New Optically Active Rh-Complexes: The Crystal Structure of [(5S)-3,4-Bis(diphenylphosphino)-5-menthoxy-2(5 H)-furanone](1,5-cyclooctadiene)rhodium-hexafluorophosphate

1989 ◽  
Vol 44 (8) ◽  
pp. 884-888 ◽  
Author(s):  
Dieter Fenske ◽  
Kurt Merzweiler
Keyword(s):  
Crystal Structure ◽  
Methyl Ester ◽  
Single Crystal ◽  
Enantiomeric Excess ◽  
Optically Active ◽  
Monoclinic Space Group ◽  
Space Group ◽  
X Ray ◽  
Lattice Constants

The chiral diphosphine 1 reacts with [(diolefin)Rh(THF)2]PF6 (diolefine: 1.5-cyclooctadiene, norbornadiene) to form the complexes 4 and 5. The structure of 4 was determined by single crystal X-ray analysis. 4 crystallizes in the monoclinic space group P21. The lattice constants (at 180 K) are: a = 974.0(6); b = 3889.2(29); c = 1309.4(5) pm; β = 105.25(4)°. The hydrogenation of methyl-α-acetamidocinnamate in the presence of 5 yields (R)-N-acetylphenylalanine methyl ester with 33% enantiomeric excess.

Bifunctional bis(oxazolines) as potential ligands in catalytic asymmetric reactions

2004 ◽  
Vol 82 (2) ◽  
pp. 306-313 ◽  
Author(s):  
Stephen Hanessian ◽  
Eric Jnoff ◽  
Noemy Bernstein ◽  
Michel Simard
Keyword(s):  
Single Crystal ◽  
Key Words ◽  
Enantiomeric Excess ◽  
Asymmetric Reactions ◽  
Potential Utility ◽  
X Ray Diffraction ◽  
Asymmetric Addition ◽  
X Ray ◽  
Oxazoline Ligands ◽  
Cu Complexes

C2-symmetrical bis(oxazoline) ligands bearing pendant alkylthio ether groups were synthesized, and the structures of Cu complexes were determined by single crystal X-ray diffraction. The potential utility in catalysis was shown in the asymmetric addition of methyllithium to an aromatic aldimine, which resulted in a mixture of products with an enantiomeric excess of 68%.Key words: two-center catalysis, bis(oxazoline), aldimine, imine alkylation.

Assembly of Layer-Type Organosilver(I) Complexes Incorporating Nitrate and Isomeric Halophenylethynide Ligands

2014 ◽  
Vol 67 (12) ◽  
pp. 1849 ◽  
Author(s):  
Ping-Shing Cheng ◽  
Sam C. K. Hau ◽  
Thomas C. W. Mak
Keyword(s):  
Single Crystal ◽  
Intermolecular Interactions ◽  
Coordination Networks ◽  
Ethynyl Group ◽  
X Ray ◽  
Nitrate Complexes

Single-crystal X-ray analysis of a series of 10 silver(i) nitrate complexes containing carbon-rich ligands each composed of a halosubstituted phenyl nucleus bearing a terminal ethynyl group at various positions provided detailed information on the influence of ligand disposition and orientation, coordination preferences, and the co-existence of silver(i)–ethynide and silver(i)–halogen interactions in the construction of coordination networks, which are consolidated by argentophilic and weak intra or intermolecular interactions.

Single crystal x-ray diffuse scattering studies of the intermolecular interactions in solid C60

1997 ◽  
Vol 86 (1-3) ◽  
pp. 2327-2328 ◽  
Author(s):  
R. Moret ◽  
P. Launois ◽  
S. Ravy ◽  
M. Julier ◽  
J.M. Godard
Keyword(s):  
Single Crystal ◽  
Intermolecular Interactions ◽  
Diffuse Scattering ◽  
X Ray
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