14182-57-1Relevant academic research and scientific papers
Iron-Catalyzed Diastereoselective Synthesis of Disubstituted Morpholines via C-O or C-N Bond Formation
Aubineau, Thomas,Dupas, Alexandre,Zeng, Tian,Cossy, Janine
supporting information, p. 525 - 531 (2020/08/28)
The diastereoselective synthesis of 2,6- and 3,5-disubstituted morpholines was achieved from 1,2-amino ethers and 1,2-hydroxy amines substituted by an allylic alcohol using an iron(III) catalyst. The morpholines were obtained either by C-O or C-N bond formation. A plausible mechanism is suggested, involving a thermodynamic equilibrium to explain the formation of the cis diastereoisomer as the major product.
Synthesis, structure, and reaction of chiral 2-azidoimidazolinium salts: (7aS)-3-azido-5,6,7,7a-tetrahydro-2-[(1R)-1-phenylethyl]-1H-pyrrolo[1,2-c]imidazolium hexafluorophosphate and 2-azido-1,3-bis[(S)-1-phenylethyl]imidazolinium hexafluorophosphate
Kitamura, Mitsuru,Ishikawa, Akihiro,Okauchi, Tatsuo
supporting information, p. 1794 - 1797 (2016/04/05)
Two chiral 2-azidoimidazolinium salts [(7aS)-3-azido-5,6,7,7a-tetrahydro-2-[(1R)-1-phenylethyl]-1H-pyrrolo[1,2-c]imidazolium hexafluorophosphate (2) and 2-azido-1,3-bis[(S)-1-phenylethyl]imidazolinium hexafluorophosphate (3)] were synthesized, and their structures were determined by X-ray single crystal structural analysis. Migratory amidation reaction of enol silyl ether with 3 proceeded, but good diastereoselectivity was not observed in the reaction.
Mild Amide-Cleavage Reaction Mediated by Electrophilic Benzylation
Yamada, Kohei,Karuo, Yukiko,Tsukada, Yuichi,Kunishima, Munetaka
supporting information, p. 14042 - 14047 (2016/09/21)
An extremely mild method for amide-cleavage by using the triazine-based benzylating reagent 4-(4,6-diphenoxy-1,3,5-triazin-2-yl)-4-benzylmorpholinium trifluoromethanesulfonate (DPT-BM), which spontaneously releases benzyl cation species when being dissolved at room temperature, has been developed. O-Benzylation of the amide with DPT-BM and the subsequent hydrolysis of the resulting intermediate benzyl imidate salt afford the corresponding amine and benzyl ester, which can be converted by hydrogenolysis into a carboxylic acid under neutral conditions. O-Benzylation proceeds depending on both steric and electronic factors around the amide group. Thus, some amides have been selectively cleaved over other amides. Furthermore, intramolecular chemoselective cleavage of an amide group in the presence of an ester group was achieved. Such selective hydrolytic reactions cannot be performed with Meerwein reagents as well as under acidic or basic hydrolytic conditions.
Characterization of an enantioselective amidase from Cupriavidus sp. KNK-J915 (FERM BP-10739) useful for enzymatic resolution of racemic 3-piperidinecarboxamide
Nojiri, Masutoshi,Taoka, Naoaki,Yasohara, Yoshihiko
, p. 136 - 142 (2014/12/10)
A novel amidase (CsAM) acting on (R,S)-N-benzyl-3-piperidinecarboxamide was purified from Cupriavidus sp. KNK-J915 (FERM BP-10739) and characterized. The enzyme acts on (R,S)-N-benzyl-3-piperidinecarboxamide S-selectively to yield (R)-N-benzyl-3-piperidinecarboxamide. Analytical gel filtration column chromatography and SDS-PAGE revealed that the enzyme is a tetramer with a subunit of approximately 47 kDa. It has a broad substrate spectrum against nitrogen-containing heterocyclic amides. Its optimal pH and temperature are 8.0-9.0 and 50 °C, respectively. The CsAM gene was cloned and sequenced, and it was found to comprise 1341 bp and encode a polypeptide of 46,388 Da. The deduced amino acid sequence exhibited 78% identity to that of a putative amidase (CnAM) from Cupriavidus necator JMP134. The cultured cells of recombinant Escherichia coli producing CnAM could be used for the S-selective hydrolysis of (R,S)-N-benzyl-3-piperidinecarboxamide but could not be used for the S-selective hydrolysis of (R,S)-3-piperidinecarboxamide because of its very low level of selectivity. In contrast, the cultured cells of recombinant E. coli producing CsAM could hydrolyze both (R,S)-N-benzyl-3-piperidinecarboxamide and (R,S)-3-piperidinecarboxamide with high S-selectivity.
Enantioselective synthesis of (R)-2-arylpropanenitriles catalysed by ene-reductases in aqueous media and in biphasic ionic liquid-water systems
Brenna, Elisabetta,Crotti, Michele,Gatti, Francesco G.,Manfredi, Alessia,Monti, Daniela,Parmeggiani, Fabio,Santangelo, Sara,Zampieri, Davila
, p. 2425 - 2431 (2014/08/18)
The enantioselective reduction of α-methylene nitrile derivatives catalysed by ene-reductases affords the corresponding (R)-2-arylpropanenitriles with high conversion values. The reaction is investigated either in aqueous medium (with an organic cosolvent or by loading the substrate onto hydrophobic resins) or in a biphasic ionic liquid-water system. The use of ionic liquids, herein with isolated ene-reductases, is found to improve the work-up and the substrate recovery method. The synthetic manipulation of the final chiral nitrile derivatives indicates how this biocatalysed method can be exploited for the preparation of a wide range of chiral compounds.
Synthesis of chiral disulfides: Potential reagents for enantioselective sulfurization
Mukhlall, Joshua A.,Noll, Bruce C.,Hersh, William H.
scheme or table, 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 conversion of α-arylnitriles by Klebsiella oxytoca
Ewert, Christian,Lutz-Wahl, Sabine,Fischer, Lutz
body text, p. 2573 - 2578 (2009/04/06)
A new bacterial isolate Klebsiella oxytoca 38.1.2 with stereoselective nitrile hydratase activity against rac-2-phenylglycine nitrile, rac-2-phenylpropionitrile and rac-mandelonitrile was investigated. The cultivation conditions for growth and nitrile hydratase formation were studied. An intracellular (S)-enantioselective nitrile hydratase and a putative (S)-selective amidase were found to be induced in the presence of rac-2-phenylpropionitrile. The temperature dependence on the enantioselectivity of the nitrile hydratase active cells was studied in more detail for the biotransformation of rac-2-phenylpropionitrile and rac-mandelonitrile. By increasing the temperature from 15 °C to 37 °C, the apparent enantiomeric ratio of the conversion of rac-2-phenylpropionitrile to (S)-2-phenylpropionamide increased from 16 to 35 at nearly 50% conversion rate. rac-Mandelonitrile was converted to (S)-mandelamide with an enantiomeric excess of up to 95% in a 80% yield without further conversion to mandelic acid.
Introduction of single mutation changes arylmalonate decarboxylase to racemase
Terao, Yosuke,Miyamoto, Kenji,Ohta, Hiromichi
, p. 3600 - 3602 (2008/09/20)
The introduction of only one mutation based on the estimated reaction mechanism endowed arylmalonate decarboxylase with a racemase activity, which catalyses racemisation of α-arylpropionates. The Royal Society of Chemistry 2006.
Enantioselective hydrolysis of various racemic α-substituted arylacetonitriles using Rhodococcus sp. CGMCC 0497
Wu, Zhong-Liu,Li, Zu-Yi
, p. 3305 - 3312 (2007/10/03)
The enantioselective hydrolysis of 17 racemic α-substituted arylacetonitriles by Rhodococcus sp. CGMCC 0497 is described. The corresponding (R)-amides and (S)-acids were obtained with excellent enantiomeric excess in most cases. The effect of steric and electronic factors on the outcome of the reactions are discussed here. The results prove that nitrile-converting enzymes are efficient tools for the synthesis of sterically unencumbered chiral α-arylpropionic acids and amides.
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.
