24461-61-8Relevant articles and documents
Enantioselective ammonolysis of phenylglycine methyl ester with lipase-pluronic nanoconjugate in tertiary butanol
Wu, Xiaoling,Wang, Rui,Zhang, Yifei,Ge, Jun,Liu, Zheng
, p. 1407 - 1410 (2014)
Asymmetrical ammonolysis of (R)- and (S)-phenylglycine methyl ester was carried out by using a lipase (CALB)-polymer (Pluronic) nanoconjugate as the catalyst, displaying a 11-fold increased catalytic rate compared to the free CALB in tertiary butanol. Graphical Abstract: The asymmetrical ammonolysis of (R)- and (S)-phenylglycine methyl ester was accomplished using a lipase-Pluronic nanoconjugate, displaying a 11-fold higher catalytic rate compared to the free lipase.[Figure not available: see fulltext.]
Dynamic kinetic resolution of phenylglycine esters via lipase-catalysed ammonolysis
Wegman,Hacking,Rops,Pereira,Van Rantwijk,Sheldon
, p. 1739 - 1750 (1999)
Ammonolysis of D,L-phenylglycine methyl ester catalysed by Novozym 435 at 40°C in tert-butyl alcohol gave D-phenylglycine amide in 78% ee at 46% conversion, corresponding to an enantiomeric ratio (E) of 16. Lowering the temperature improved the enantioselectivity (E = 52 at -20°C). Combination of ammonolysis with pyridoxal-catalysed in situ racemisation of the unconverted ester (dynamic kinetic resolution), at -20°C, gave D- phenylglycine amide with 88% ee at 85% conversion. The amide racemised much slower than the ester at this low temperature.
Rubrosides A-H, new bioactive tetramic acid glycosides from the marine sponge Siliquariaspongia japonica
Sata,Wada,Matsunaga,Watabe,Van Soest,Fusetani
, p. 2331 - 2339 (1999)
Eight new tetramic acid glycosides named rubrosides A-H have been isolated from the marine sponge Siliquariaspongia japonica. Their structures were elucidated on the basis of spectral data as tetramic acid glycosides containing polyenes terminating in a 4-chloro-2-methyltetrahydrofuran ring. The absolute stereochemistry of the furan functionality in the two major metabolites, rubrosides D and F, was determined by the NMR method using chiral anisotropic reagents for tetrahydro-2-furoic acid derived by RuO4 oxidation. The absolute stereochemistry of tetramic acid and of the sugar moieties in all rubrosides was deduced by chiral GC analysis of chemical degradation products. The rubrosides induced numerous large intracellular vacuoles in 3Y1 rat fibroblasts at concentrations of 0.5-1.0 μg/mL, and rubrosides A, C, D, and E were cytotoxic against P388 murine leukemia cells with IC50 values of 0.046-0.21 μg/mL. Most rubrosides show antifungal activity against Aspergillus fumigatus and Candida albicans.
Preparation method of oxazolidinone compound
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Paragraph 0051-0053, (2021/11/10)
The preparation method comprises the following steps 1): dissolving aromatic amino acid in methanol, dissolving the aromatic amino acid in methanol, heating up to 50 - 60 °C heat preservation 1 - 2h, 2) reducing: adding a catalytic amount of lithium salt in ethanol water as a solvent. 3) Ring-closing: toluene is used as a solvent, a reduction product and diethyl carbonate are added to 100 °C, a sodium methoxide solution is added dropwise, and the product is obtained after completion of the dropwise addition and after-treatment and purification after completion of the normal pressure distillation to the temperature of 100 °C heat preservation. The lithium salt is introduced to participate in the reaction, sodium borohydride is selected as a solvent, sodium borohydride is completely dissolved, and the lithium salt can be free from the compound to improve the reaction activity, so that the use amount of sodium borohydride is reduced to 2 equivalent, and the production cost is remarkably reduced.
Highly Stable Zr(IV)-Based Metal-Organic Frameworks for Chiral Separation in Reversed-Phase Liquid Chromatography
Jiang, Hong,Yang, Kuiwei,Zhao, Xiangxiang,Zhang, Wenqiang,Liu, Yan,Jiang, Jianwen,Cui, Yong
supporting information, p. 390 - 398 (2021/01/13)
Separation of racemic mixtures is of great importance and interest in chemistry and pharmacology. Porous materials including metal-organic frameworks (MOFs) have been widely explored as chiral stationary phases (CSPs) in chiral resolution. However, it remains a challenge to develop new CSPs for reversed-phase high-performance liquid chromatography (RP-HPLC), which is the most popular chromatographic mode and accounts for over 90% of all separations. Here we demonstrated for the first time that highly stable Zr-based MOFs can be efficient CSPs for RP-HPLC. By elaborately designing and synthesizing three tetracarboxylate ligands of enantiopure 1,1′-biphenyl-20-crown-6, we prepared three chiral porous Zr(IV)-MOFs with the framework formula [Zr6O4(OH)8(H2O)4(L)2]. They share the same flu topological structure but channels of different sizes and display excellent tolerance to water, acid, and base. Chiral crown ether moieties are periodically aligned within the framework channels, allowing for stereoselective recognition of guest molecules via supramolecular interactions. Under acidic aqueous eluent conditions, the Zr-MOF-packed HPLC columns provide high resolution, selectivity, and durability for the separation of a variety of model racemates, including unprotected and protected amino acids and N-containing drugs, which are comparable to or even superior to several commercial chiral columns for HPLC separation. DFT calculations suggest that the Zr-MOF provides a confined microenvironment for chiral crown ethers that dictates the separation selectivity.
