74042-63-0Relevant articles and documents
Absolute configuration and polymorphism of 2-phenylbutyramide and α-methyl-α-phenylsuccinimide
Khrustalev, Victor N.,Sandhu, Bhupinder,Bentum, Samuel,Fonari, Alexandr,Krivoshein, Arcadius V.,Timofeeva, Tatiana V.
, p. 3360 - 3369 (2014/07/21)
Crystal structures of racemic and homochiral forms of 2-phenylbutyramide (1) and 3-methyl-3-phenylpyrrolidine-2,5-dione (2) were investigated in detail by a single crystal X-ray diffraction study. Absolute configurations of the homochiral forms of 1 and 2, obtained by chromatographic separation of racemates, were determined. It was revealed that racemate and homochiral forms of 1 are very similar in terms of supramolecular organization (H-bonded ribbons) in crystal, infrared (IR) spectral characteristics, and melting points. The presence of two different molecular conformations in homochiral forms of 1 allowed mimicking of crystal packing of the H-bonded ribbons in racemate 1. Two polymorph modifications (monoclinic and orthorhombic) comprising very similar H-bonded zigzag-like chains were found for the homochiral forms of compound 2 that were significantly different in terms of crystal structure, IR spectra, and melting points from the racemic form of 2. Unlike compound 1, homochiral forms of compound 2 have a higher density than the corresponding racemate which contradicts the Wallach rule and indicates that, in this case, homochiral forms are more stable than racemate forms.
Synthesis of chiral disulfides: Potential reagents for enantioselective sulfurization
Mukhlall, Joshua A.,Noll, Bruce C.,Hersh, William H.
, p. 199 - 212 (2012/01/06)
Synthesis of chiral phosphorothioates for use as antisense oligonucleotides might benefit from the use of chiral disulfides. This paper reports the synthesis of chiral analogs of phenylacetyl disulfide and of 5-methyl-3H-1,2,4-dithiazol-3-one from the same set of 2-arylalkanoic acids. The X-ray crystal structures of the disulfides derived from (R) and [S]-2-phenylpropanoic acid establish the stereochemistry and the helicity of these materials, and density functional theory calculations suggest that the high specific rotations can be due to preferred retention of this helicity in solution. Chiral HPLC showed that the final products were formed with enantiomeric purities from 86.1% to >99.9%.
Enantioselective biotransformations of racemic α-substituted phenylacetonitriles and phenylacetamides using Rhodococcus sp. AJ270
Wang, Mei-Xiang,Lu, Gang,Ji, Gai-Jiao,Huang, Zhi-Tang,Meth-Cohn, Otto,Colby, John
, p. 1123 - 1135 (2007/10/03)
Rhodococcus sp. AJ270 is an efficient whole-cell system able to catalyze the stereoselective conversions of racemic α-substituted phenylacetonitriles and amides under very mild conditions into enantiopure carboxylic acids and derivatives. The nitrile hydratase involved generally has a broad substrate spectrum against phenylacetonitriles irrespective of the electronic nature of the α-substituent while the amidase is very sensitive to both the electronic and steric factors of the substituent of amides. The overall enantioselectivity of nitrile hydrolysis is mainly determined by the combination of selectivities of nitrile hydratase and of amidase, with the latter being a major contributor. The amidase has high S-enantiocontrol against amides while the nitrile hydratase exhibits low R-selectivity against nitriles. The scope and limitations of this enantioselective biotransformation process are discussed. Copyright (C) 2000 Elsevier Science Ltd.
