7782-24-3Relevant articles and documents
Enantioselective oxidation of (±)-2-phenyl-1-propanol to (S)-2-phenyl-1-propionic acid with Acetobacter aceti: Influence of medium engineering and immobilization
Gandolfi, Raffaella,Borrometi, Antonella,Romano, Andrea,Sinisterra Gago, Jose V.,Molinari, Francesco
, p. 2345 - 2349 (2002)
The enantioselective oxidation of (RS)-2-phenyl-1-propanol to (S)-2-phenylpropionic acid catalysed by Acetobacter aceti occurred under very mild conditions. The rate, substrate tolerance and enantioselectivity (enantiomeric ratio, E >200) can be increased
The Mechanism and Stereochemistry of Asymmetric Transformation via Chiral Oxazolines
Shibata, Saizo,Matsushita, Hajime,Kaneko, Hajime,Noguchi, Masao,Sakurai, Takao,et al.
, p. 3531 - 3535 (1984)
The stereoselectivity of asymmetric transformation of 2-substituted alkanoic acid via oxazolines was clarified by measuring the isomeric ratio of 13C-labeled lithio oxazolines by 13C NMR.The mechanism of the process was discussed fro
Enantioselective oxidation of (RS)-2-phenyl-1-propanol to (S)-2-phenylpropanoic acid with Gluconobacter oxydans: Simplex optimization of the biotransformation
Molinari, Francesco,Villa, Raffaella,Aragozzini, Fabrizio,Leon, Rosa,Prazeres, Duarte M. F.
, p. 3003 - 3009 (1999)
The microbial oxidation of racemic 2-phenyl-1-propanol by Gluconobacter oxydans DSM 50049 was investigated. Whole bacterial cells were used to produce (S)-(+)-2-phenylpropanoic acid with high enantiomeric excess (E>200). A simplex sequential method was em
Optimization of the chiral inversion of 2-phenylpropionic acid by Verticillium lecanii
Thomason, Michael J.,Rhys-Williams, William,Lloyd, Andrew W.,Hanlon, Geoffrey W.
, p. 263 - 269 (1997)
Previous studies have demonstrated that Verticillium lecanii might be used as a microbial model of the inversion of 2-arylpropionic acids in man. This paper describes the optimization of the inversion process in respect of culture medium, pH, cell density and substrate concentration. The study demonstrates that optimum inversion occurs in Sorensen's phosphate buffer at pH 5.5. The extent and rate of inversion were also shown to be dependent on substrate concentration and cell density. This study will form the basis of the development of a microbial model of the metabolism of 2-arylpropionic acids which might be suitable for the in-vitro screening of new compounds in this class.
Experimental and Model Studies on Continuous Separation of 2-Phenylpropionic Acid Enantiomers by Enantioselective Liquid-Liquid Extraction in Centrifugal Contactor Separators
Feng, Xiaofeng,Tang, Kewen,Zhang, Pangliang,Yin, Shuangfeng
, p. 235 - 244 (2016)
Multistage enantioselective liquid-liquid extraction (ELLE) of 2-phenylpropionic acid (2-PPA) enantiomers using hydroxypropyl-β-cyclodextrin (HP-β-CD) as extractant was studied experimentally in a counter-current cascade of centrifugal contactor separators (CCSs). Performance of the process was evaluated by purity (enantiomeric excess, ee) and yield (Y). A multistage equilibrium model was established on the basis of single-stage model for chiral extraction of 2-PPA enantiomers and the law of mass conservation. A series of experiments on the extract phase/washing phase ratio (W/O ratio), extractant concentration, the pH value of aqueous phase, and the number of stages was conducted to verify the multistage equilibrium model. It was found that model predictions were in good agreement with the experimental results. The model was applied to predict and optimize the symmetrical separation of 2-PPA enantiomers. The optimal conditions for symmetric separation involves a W/O ratio of 0.6, pH of 2.5, and HP-β-CD concentration of 0.1 mol L-1 at a temperature of 278 K, where eeeq (equal enantiomeric excess) can reach up to 37% and Yeq (equal yield) to 69%. By simulation and optimization, the minimum number of stages was evaluated at 98 and 106 for eeeq > 95% and eeeq > 97%. Chirality 28:235-244, 2016.
Enantioselective Synthesis of Chiral Carboxylic Acids from Alkynes and Formic Acid by Nickel-Catalyzed Cascade Reactions: Facile Synthesis of Profens
Fu, Kaiyue,Ma, Yu,Sun, Yaxin,Tang, Bo,Yang, Guang,Yang, Peng,Yue, Jieyu,Zhang, Li,Zhou, Jianrong Steve
supporting information, (2021/11/22)
We report a stereoselective conversion of terminal alkynes to α-chiral carboxylic acids using a nickel-catalyzed domino hydrocarboxylation-transfer hydrogenation reaction. A simple nickel/BenzP* catalyst displayed high activity in both steps of regioselective hydrocarboxylation of alkynes and subsequent asymmetric transfer hydrogenation. The reaction was successfully applied in enantioselective preparation of three nonsteroidal anti-inflammatory profens (>90 % ees) and the chiral fragment of AZD2716.
Reshaping the active pocket of esterase Est816 for resolution of economically important racemates
Fan, Xinjiong,Fu, Yao,Liu, Xiaolong,Zhao, Meng
, p. 6126 - 6133 (2021/09/28)
Bacterial esterases are potential biocatalysts for the production of optically pure compounds. However, the substrate promiscuity and chiral selectivity of esterases usually have a negative correlation, which limits their commercial value. Herein, an efficient and versatile esterase (Est816) was identified as a promising catalyst for the hydrolysis of a wide range of economically important substrates with low enantioselectivity. We rationally designed several variants with up to 11-fold increased catalytic efficiency towards ethyl 2-arylpropionates, mostly retaining the initial substrate scope and enantioselectivity. These variants provided a dramatic increase in efficiency for biocatalytic applications. Based on the best variant Est816-M1, several variants with higher or inverted enantioselectivity were designed through careful analysis of the structural information and molecular docking. Two stereoselectively complementary mutants, Est816-M3 and Est816-M4, successfully overcame and even reversed the low enantioselectivity, and several 2-arylpropionic acid derivatives with highEvalues were obtained. Our results offer potential industrial biocatalysts for the preparation of structurally diverse chiral carboxylic acids and further lay the foundation for improving the catalytic efficiency and enantioselectivity of esterases.
Palladium-Catalyzed Asymmetric Markovnikov Hydroxycarbonylation and Hydroalkoxycarbonylation of Vinyl Arenes: Synthesis of 2-Arylpropanoic Acids
Guan, Zheng-Hui,Ren, Zhi-Hui,Wang, Yuan,Yang, Hui-Yi,Yao, Ya-Hong,Zou, Xian-Jin
supporting information, p. 23117 - 23122 (2021/09/18)
Asymmetric hydroxycarbonylation is one of the most fundamental yet challenging methods for the synthesis of carboxylic acids. Herein, we reported the development of a palladium-catalyzed highly enantioselective Markovnikov hydroxycarbonylation of vinyl arenes with CO and water. A monodentate phosphoramidite ligand L6 plays vital role in the reaction. The reaction tolerates a range of functional groups, and provides a facile and atom-economical approach to an array of 2-arylpropanoic acids including several commonly used non-steroidal anti-inflammatory drugs. The catalytic system has also enabled an asymmetric Markovnikov hydroalkoxycarbonylation of vinyl arenes with alcohols to afford 2-arylpropanates. Mechanistic investigations suggested that the hydropalladation is irreversible and is the regio- and enantiodetermining step, while hydrolysis/alcoholysis is probably the rate-limiting step.
Efficient Assay for the Detection of Hydrogen Peroxide by Estimating Enzyme Promiscuous Activity in the Perhydrolysis Reaction
Wilk, Monika,Ostaszewski, Ryszard
, p. 1464 - 1469 (2021/02/01)
Hydrogen peroxide is an ideal oxidant in view of its availability, atom economy, or green aspects. Furthermore, it is produced by the cell mitochondria and plays a meaningful role in controlling physiological processes, but its unregulated production leads to the destruction of organs. Due to its diverse roles, a fast and selective method for hydrogen peroxide detection is the major limitation to preventing the negative effects caused by its excess. Therefore, we aimed to develop an efficient assay for the detection of H2O2. For this purpose, we combined the enzymatic method for the detection of hydrogen peroxide with the estimation of the promiscuity of various enzymes. We estimated the activity of an enzyme in the reaction of p-nitrophenyl esters with hydrogen peroxide resulting in the formation of peracid. To our knowledge, there is no example of a simple, multi-sensor demonstrating the promiscuous activity of an enzyme and detecting hydrogen peroxide in aqueous media.
1,3,2-Diazaphospholenes Catalyze the Conjugate Reduction of Substituted Acrylic Acids
Reed, John H.,Cramer, Nicolai
, p. 4262 - 4266 (2020/07/13)
The potent nucleophilicity and remarkably low basicity of 1,3,2-diazaphospholenes (DAPs) is exploited in a catalytic, metal-free 1,4-reduction of free α,β-unsaturated carboxylic acids. Notably, the reduction occurs without a prior deprotonation of the carboxylic acid moiety and hence does not consume an additional hydride equivalent. This highlights the excellent nucleophilic character and low basicity of DAP-hydrides. Functional groups such as Cbz group or alkyl halides which can be problematic with classical transition-metal catalysts are well tolerated in the DAP-catalyzed process. Moreover, the transformation is characterized by a low catalyst loading, mild reaction conditions at ambient temperature as well as fast reaction times and high yields. The proof-of-principle for a catalytic enantioselective version is described.
