Process for the preparation of optically active 4-oxochroman-2-carboxylic acid derivatives
申请人:SANWA KAGAKU KENKYUSHO CO., LTD.
公开号:EP0488047A1
公开(公告)日:1992-06-03
There is described a process for the preparation of optically active 4-oxochroman-2-carboxylic acid derivatives as intermediates for synthesizing hydantoin compounds which shows strong inhibition to aldose reductases to cure incurable complications of diabetes. According to the process, the derivatives are prepared by fractionally recrystallizing a salt of racemic 4-oxochroman-2-carboxylic acid derivative with an optically active secondary amine or diamine.
Mechanisms of hydrogenation. Part IX. Induced asymmetry in homogeneous hydrogenation at a rhodium complex by the use of optically active amide ligands
作者:P. Abley、F. J. McQuillin
DOI:10.1039/j39710000844
日期:——
Homogeneoushydrogenation of methyl trans- or cis-3-phenylbut-2-enoate at a rhodiumcomplex in presence of a series of opticallyactive amides yields methyl 3-phenylbutanoate showing an appreciable degree of optical activity depending on the amide. The asymmetry of the methyl 3-phenylbutanoate formed is correlated with the chirality of the amideligand in the complex.
Supramolecular interactions in X-ray structures of oxalamides: Green synthesis and characterization
作者:Areli A. Molina-Paredes、Jesús A. Lara-Cerón、Marisol Ibarra-Rodríguez、Casiano del Angel-Mosqueda、H.V. Rasika Dias、Víctor M. Jiménez-Pérez、Blanca M. Muñoz-Flores
DOI:10.1016/j.molstruc.2022.133144
日期:2022.9
high purity. NMR and single-crystal X-ray diffraction results revealed the characteristic intermolecular and intramolecular interactions of N,N'-oxalamides across the amide core. Notably, the X-raystructure of 1 reveals that amide hydrogen presents a trifurcated character due to the intra and intermolecular hydrogen interactions. Additionally, the crystal structure of lithium complex 7 shows CH/π stacking
如今,全世界化学家面临的最大挑战之一是设计具有高原子经济性和低 E 因子的环保合成方法。无溶剂反应是避免浪费的最佳方法之一。在这里,我们报告了在草酰氯和相应的伯胺(2-氟苯胺(1)、2,6-二异丙基苯胺(2)、2,6-二甲基苯胺(3 )之间进行的五种草酰胺的简短系列无溶剂合成。 )、(1R)-1-苯乙胺 ( 4 )和顺式-桃金娘胺 ( 5 ) 在冰浴中;HCl 的释放被饱和 NaOH 溶液中和。所有草酰胺1-5以良好的收率和高纯度提供。NMR 和单晶 X 射线衍射结果揭示了N,N'-草酰胺在酰胺核心上的特征分子间和分子内相互作用。值得注意的是, 1的 X 射线结构表明,由于分子内和分子间的氢相互作用,酰胺氢呈现出三叉特征。此外,锂络合物7的晶体结构显示芳环和四氢呋喃分子之间的CH/π堆积。
Resolution of α-phenylethylamine by its acidic derivatives
α-Phenylethylamine was resolved by its own derivatives formed with a homologous series of dicarboxylic acids. The structure of the oxalamic acid diastereoisomeric salts was investigated by the single-crystal X-ray diffraction method.
The reaction between bis-imidoylchlorides 2 derived from oxalic acid and several aromatic and aliphatic amines was investigated. While primary aromatic amines need a thermical activation by refluxing, primary aliphatic amines give mainly at room temperature the amidines 3 in moderatly up to good yields.Proceeding from enantiomeric pure amines e.g. (R)- or (S)-1-phenethylamine the new homochiral oxalic amidines 3y and 3z with C-2-symmetry were obtained. Several secondary amines react with the bis-imidoylchloride 2a to give via intramolecular cycloacylation derivatives of isatine. The new synthesized amidines 3 perform systems with a strong molecular dynamic like prototropie and E/Z-interconversion. All new compounds described were characterized by elemental analysis and spectroscopic methods.