146300-52-9Relevant academic research and scientific papers
HPLC separation of 2-aryloxycarboxylic acid enantiomers on chiral stationary phases
Charushin, V. N.,Chulakov, E. N.,Krasnov, V. P.,Levit, G. L.,Sadretdinova, L. Sh.,Tumashov, A. A.,Vakarov, S. A.
, p. 900 - 907 (2021/06/07)
The possibility for separating enantiomers of a number of practically significant 2-aryloxycarboxylic acids was studied by normal- and reversed-phase HPLC on popular chiral stationary phases. The best separation parameters were achieved on the chiral phases with the polysaccharide base Chiralcel OD-H and Chiralpack AD under the normal-phase HPLC conditions. The (S)- and (R)-enantiomers of 2-(1-naphthyloxy)- and 2-(2-iodophenoxy)propionic acids with enantiomeric excess ee >99% were isolated using preparative chiral HPLC.
Enantioselective Synthesis of α-Thiocarboxylic Acids by Nitrilase Biocatalysed Dynamic Kinetic Resolution of α-Thionitriles
Lauder, Kate,Anselmi, Silvia,Finnigan, James D.,Qi, Yuyin,Charnock, Simon J.,Castagnolo, Daniele
supporting information, p. 10422 - 10426 (2020/07/24)
The enantioselective synthesis of α-thiocarboxylic acids by biocatalytic dynamic kinetic resolution (DKR) of nitrile precursors exploiting nitrilase enzymes is described. A panel of 35 nitrilase biocatalysts were screened and enzymes Nit27 and Nit34 were found to catalyse the DKR of racemic α-thionitriles under mild conditions, affording the corresponding carboxylic acids with high conversions and good-to-excellent ee. The ammonia produced in situ during the biocatalytic transformation favours the racemization of the nitrile enantiomers and, in turn, the DKR without the need of any external additive base.
Kinetic resolution of α-substituted alkanoic acids promoted by homobenzotetramisole
Yang, Xing,Birman, Vladimir B.
supporting information; experimental part, p. 11296 - 11304 (2011/10/19)
A new method for catalytic nonenzymatic kinetic resolution of α-substituted alkanoic acids has been developed, which relies on their activation with DCC followed by enantioselective alcoholysis of the intermediate symm-anhydrides in the presence of the amidine-based catalyst homobenzotetramisole (HBTM). Moderate to excellent selectivity factors (s=5-96) have been obtained in the case of several classes of substrates, namely, α-aryl-, α-aryloxy/alkoxy-, α-halo-, α-azido-, and α-phthalimido-alkanoic acids. Under similar conditions, α-(arylthio/alkylthio)-alkanoic acids undergo dynamic kinetic resolution providing corresponding esters in up to 92 % ee and up to 93 % yield. Copyright
Nonenzymatic dynamic kinetic resolution of α-(arylthio)- and α-(alkylthio)alkanoic acids
Yang, Xing,Birman, Vladimir B.
, p. 5553 - 5555 (2011/07/09)
Dynamic solution: The title acids undergo dynamic kinetic resolution during an enantioselective esterification catalyzed by (S)-homobenzotetramisole ((S)-HBTM; see scheme). This method extends the scope of the carboxylic acid derivatives that are amenable to the nonenzymatic version of this transformation. Copyright
Homobenzotetramisole-catalyzed kinetic resolution of α-Aryl-, α-Aryloxy-, and α-Arylthioalkanoic acids
Yang, Xing,Birman, Vladimir B.
supporting information; experimental part, p. 2301 - 2304 (2010/01/19)
Effective kinetic resolutions of α-aryl-, αaryloxy-, and α-arylthioalkanoic acids have been achieved via in situ generation of their symmetrical anhydrides and enantioselective alcoholysis in the presence of homobenzotetramisole (HBTM) 3.
Microbial deracemization of α-substituted carboxylic acids: Control of the reaction path
Kato, Dai-Ichiro,Miyamoto, Kenji,Ohta, Hiromichi
, p. 2965 - 2973 (2007/10/03)
A novel approach to preparing optically active α-substituted carboxylic acids using the whole cells of Nocardia diaphanozonaria JCM 3208 is described. When 2-phenylthiopropanoic acid and 2-methyl-3-phenylpropanoic acid were subjected to the reaction under aerobic conditions, the oxidation reaction proceeded preferentially rather than deracemization of these substrates. Herein, we report the design of reaction conditions to increase the deracemization activity in preference to oxidation reactions. In addition, we have successfully detected a metabolic intermediate in the reaction mixture of 2-methyl-3-phenylpropanoic acid, which indicates that the deracemization is a competitive reaction against the α-oxidation pathway of fatty acid metabolism.
Microbial deracemization of α-substituted carboxylic acids: Substrate specificity and mechanistic investigation
Kato, Dai-Ichiro,Mitsuda, Satoshi,Ohta, Hiromichi
, p. 7234 - 7242 (2007/10/03)
A new enzymatic method for the preparation of optically active α-substituted carboxylic acids is reported. This technique is called deracemization reaction, which provides us with a route to obtain the enantiomerically pure compounds, theoretically in 100% yield starting from the racemic mixture. This means that the synthesis of a racemate is almost equal to the synthesis of the optically active compound, and this concept is entirely different from the commonly accepted one in the asymmetric synthesis. Using the growing cell system of Nocardia diaphanozonaria JCM3208, racemates of 2-aryl- and 2-aryloxypropanoic acid are deracemized smoothly and (R)-form-enriched products are recovered in high chemical yield (>50%). In addition, using optically active starting compounds and deuterated derivatives as well as inhibitors, we have disclosed the fact that a new type of enzyme takes part in this biotransformation, and that the reaction proceeds probably via the same mechanism as that in rat liver.
Preparation of enantiomerically pure sulfoxides from lactic acid and 3-hydroxybutyric acid. Isopropenyl tolyl sulfoxide and 2-(phenylsulfinyl)acrylate
Breitschuh,Seebach
, p. 1170 - 1178 (2007/10/02)
The EPC-synthesis of sulfoxides from readily available starting materials ('chiral pool') is demonstrated for the first time. Cyclic and open-chain thioethers derived from lactic and 3-hydroxybutyric acid are oxidized to sulfoxides, and the resulting prod
