84624-17-9Relevant articles and documents
Novel chiral stationary phases based on 3,5-dimethyl phenylcarbamoylated β-cyclodextrin combining cinchona alkaloid moiety
Zhu, Lunan,Zhu, Junchen,Sun, Xiaotong,Wu, Yaling,Wang, Huiying,Cheng, Lingping,Shen, Jiawei,Ke, Yanxiong
, p. 1080 - 1090 (2020/05/25)
Novel chiral selectors based on 3,5-dimethyl phenylcarbamoylated β-cyclodextrin connecting quinine (QN) or quinidine (QD) moiety were synthesized and immobilized on silica gel. Their chromatographic performances were investigated by comparing to the 3,5-dimethyl phenylcarbamoylated β-cyclodextrin (β-CD) chiral stationary phase (CSP) and 9-O-(tert-butylcarbamoyl)-QN-based CSP (QN-AX). Fmoc-protected amino acids, chiral drug cloprostenol (which has been successfully employed in veterinary medicine), and neutral chiral analytes were evaluated on CSPs, and the results showed that the novel CSPs characterized as both enantioseparation capabilities of CD-based CSP and QN/QD-based CSPs have broader application range than β-CD-based CSP or QN/QD-based CSPs. It was found that QN/QD moieties play a dominant role in the overall enantioseparation process of Fmoc-amino acids accompanied by the synergistic effect of β-CD moiety, which lead to the different enantioseparation of β-CD-QN-based CSP and β-CD-QD-based CSP. Furthermore, new CSPs retain extraordinary enantioseparation of cyclodextrin-based CSP for some neutral analytes on normal phase and even exhibit better enantioseparation than the corresponding β-CD-based CSP for certain samples.
Structure-guided engineering of: Meso -diaminopimelate dehydrogenase for enantioselective reductive amination of sterically bulky 2-keto acids
Cheng, Xinkuan,Chen, Xi,Feng, Jinhui,Wu, Qiaqing,Zhu, Dunming
, p. 4994 - 5002 (2018/10/17)
meso-Diaminopimelate dehydrogenase (DAPDH) and mutant enzymes are an excellent choice of biocatalysts for the conversion of 2-keto acids to the corresponding d-amino acids. However, their application in the enantioselective reductive amination of bulky 2-keto acids, such as phenylglyoxylic acid, 2-oxo-4-phenylbutyric acid, and indole-3-pyruvic acid, is still challenging. In this study, the structure-guided site-saturation mutagenesis of a Symbiobacterium thermophilum DAPDH (StDAPDH) gave rise to a double-site mutant W121L/H227I, which showed dramatically improved enzyme activities towards various 2-keto acids including these sterically bulky substrates. Several d-amino acids were prepared in optically pure form. The molecular docking of substrates into the active sites of wild-type and mutant W121L/H227I enzymes revealed that the substrate binding cavity of the mutant enzyme was reshaped to accommodate these bulky substrates, thus leading to higher enzyme activity. These results lay a foundation for further shaping the substrate binding pocket and manipulating the interactions between the substrate and binding sites to access highly active d-amino acid dehydrogenases for the preparation of synthetically challenging d-amino acids.
Ureidopeptide-based Bronsted bases: Design, synthesis and application to the catalytic enantioselective synthesis of β-amino nitriles from (arylsulfonyl)acetonitriles
Diosdado, Saioa,Lopez, Rosa,Palomo, Claudio
, p. 6526 - 6531 (2014/06/09)
The addition of cyanoalkyl moieties to imines is a very attractive method for the preparation of β-amino nitriles. We present a highly efficient organocatalytic methodology for the stereoselective synthesis of β-amino nitriles, in which the key to success is the use of ureidopeptide-based Bronsted base catalysts in combination with (arylsulfonyl)acetonitriles as synthetic equivalents of the acetonitrile anion. The method gives access to a variety of β-amino nitriles with good yields and excellent enantioselectivities, and broadens the stereoselective Mannich-type methodologies available for their synthesis. Learning from peptides: A concise route for the catalytic enantioselective synthesis of β-amino nitriles has been achieved by using ureidopeptide-based Bronsted bases as catalysts in the Mannich reaction of N-Boc imines and (arylsulfonyl)acetonitriles (see scheme; Boc=tert-butoxycarbonyl, napht=naphthyl, TMS=trimethylsilyl).
