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Journal articles on the topic 'Enantioselectivity'

Author: Grafiati

Published: 4 June 2021

Last updated: 25 July 2025

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1

Ying, Xiangxian, Shihua Yu, Meijuan Huang, et al. "Engineering the Enantioselectivity of Yeast Old Yellow Enzyme OYE2y in Asymmetric Reduction of (E/Z)-Citral to (R)-Citronellal." Molecules 24, no. 6 (2019): 1057. http://dx.doi.org/10.3390/molecules24061057.

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The members of the Old Yellow Enzyme (OYE) family are capable of catalyzing the asymmetric reduction of (E/Z)-citral to (R)-citronellal—a key intermediate in the synthesis of L-menthol. The applications of OYE-mediated biotransformation are usually hampered by its insufficient enantioselectivity and low activity. Here, the (R)-enantioselectivity of Old Yellow Enzyme from Saccharomyces cerevisiae CICC1060 (OYE2y) was enhanced through protein engineering. The single mutations of OYE2y revealed that the sites R330 and P76 could act as the enantioselectivity switch of OYE2y. Site-saturation mutage

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2

Majewski, Marek, Ryszard Lazny, and Agnieszka Ulaczyk. "Enantioselective ring opening of tropinone. A new entry into tropane alkaloids." Canadian Journal of Chemistry 75, no. 6 (1997): 754–61. http://dx.doi.org/10.1139/v97-091.

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The lithium enolate of tropinone reacts with alkyl chloroformates to give 6-N-carboalkoxy-N-methyl-2-cycloheptenones (4). These compounds can be produced enantioselectively, in up to 95% ee, if chiral lithium amides (derived from optically pure amines 5–7) are used for deprotonation of tropinone in the presence of additives. The effect of additives such as LiCl, LiBr, LiF, LiClO4, CeCl3, ZnCl2, LiOH, TMEDA, HMPA, and DMPU on enantioselectivity of this deprotonation–ring opening sequence varies from slight to very large depending on the chiral amide – additive combination. Especially large incr

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3

Filippi, A., A. Giardini, S. Piccirillo, and M. Speranza. "Gas-phase enantioselectivity." International Journal of Mass Spectrometry 198, no. 3 (2000): 137–63. http://dx.doi.org/10.1016/s1387-3806(00)00196-2.

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4

Feng, Binbin, Xia Li, Lijun Jin, et al. "Engineering the Activity of Old Yellow Enzyme NemR-PS for Efficient Reduction of (E/Z)-Citral to (S)-Citronellol." Catalysts 12, no. 6 (2022): 631. http://dx.doi.org/10.3390/catal12060631.

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The cascade catalysis of old yellow enzyme, alcohol dehydrogenase and glucose dehydrogenase has become a promising approach for one pot, two-step reduction of (E/Z)-citral to (S)-citronellol, serving as a chiral alcohol with rose fragrance. During the multi-enzymatic cascade catalysis, old yellow enzyme is responsible for the reduction of the conjugated C=C and the introduction of the chiral center, requiring high activity and (S)-enantioselectiviy. Herein, to improve the activity of the old yellow enzyme from Providencia stuartii (NemR-PS) with strict (S)-enantioselectivity, the semi-rational

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5

Ragusa, Andrea, Joseph M. Hayes, Mark E. Light, and Jeremy D. Kilburn. "Predicting Enantioselectivity: Computation as an Efficient “Experimental” Tool for Probing Enantioselectivity." European Journal of Organic Chemistry 2006, no. 16 (2006): 3545–49. http://dx.doi.org/10.1002/ejoc.200600368.

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6

Nguyen, Zachary A., Dylan Boucher, and Shelley D. Minteer. "Electrolyte Induced Solvent Cage Effects for Enantioselective Electrosynthesis." ECS Meeting Abstracts MA2022-02, no. 53 (2022): 2514. http://dx.doi.org/10.1149/ma2022-02532514mtgabs.

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Electrochemistry provides a tunable, regioselective, and green alternative to traditional synthetic organic methods, and access to reactive intermediates. Problematically, electrochemical redox events often go through planar radical intermediates, thus destroying enantioselectivity. As such, researchers have sought the “chiral electron”, a general methodology to impart enantioselectivity to electroorganic reactions. One strategy has been asymmetric transition metal catalysis while replacing the typical stochiometric redox reagent needed with electricity, thus providing a chiral pathway for ele

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7

Reetz, Manfred T., Sheng Wu, Huabao Zheng, and Shreenath Prasad. "Directed evolution of enantioselective enzymes: An unceasing catalyst source for organic chemistry." Pure and Applied Chemistry 82, no. 8 (2010): 1575–84. http://dx.doi.org/10.1351/pac-con-09-09-16.

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Directed evolution has emerged as a powerful method for engineering essentially any catalytic parameter of enzymes for application in synthetic organic chemistry and biotechnology, including thermostability, substrate scope, and enantioselectivity. Enantioselectivity is especially crucial when applying biocatalysts to synthetic organic chemistry. This contribution focuses on recent methodology developments in laboratory evolution of stereoselective enzymes, hydrolases, and monooxygenases serving as the enzymes. Specifically, iterative saturation mutagenesis (ISM) has been developed as an unusu

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8

Wang, Tairan, Ran Wei, Yingting Feng, et al. "Engineering of Yeast Old Yellow Enzyme OYE3 Enables Its Capability Discriminating of (E)-Citral and (Z)-Citral." Molecules 26, no. 16 (2021): 5040. http://dx.doi.org/10.3390/molecules26165040.

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The importance of yeast old yellow enzymes is increasingly recognized for direct asymmetric reduction of (E/Z)-citral to (R)-citronellal. As one of the most performing old yellow enzymes, the enzyme OYE3 from Saccharomyces cerevisiae S288C exhibited complementary enantioselectivity for the reduction of (E)-citral and (Z)-citral, resulting in lower e.e. value of (R)-citronellal in the reduction of (E/Z)-citral. To develop a novel approach for the direct synthesis of enantio-pure (R)-citronellal from the reduction of (E/Z)-citral, the enzyme OYE3 was firstly modified by semi-rational design to i

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9

Cowan, Don A., and Helen D. Simpson. "Controlling the enantioselectivity of sec-alcohol dehydrogenase from thermoanaerobacterium sp. KET4BL." Protein & Peptide Letters 4, no. 1 (1997): 25–32. http://dx.doi.org/10.2174/092986650401221012141152.

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Abstract: The control of enantioselectivity by miscible organic solvents of a thermostable sec-ADH, purified from an anaerobic, thermophilic bacterium designated Therm.oanaerobacterium sp. Ket4B1, has been investigated. Experiments to compare the initial rates of oxidation of (R)-.and (S)-butan-2-ol in the presence of Oto 40% (v/v) acetonitrile revealed that the v0Rfv0s initial ratio increased with increasing solvent concentration. Other co-solvents were also found to influence the enantioselectivity but there was no direct correlation between either the log P or the dielectric constant of the

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10

Gan, Li, and Michael A. Brook. "Hydrosilylation of ketones catalyzed by C2-symmetric proline-derived complexes." Canadian Journal of Chemistry 84, no. 10 (2006): 1416–25. http://dx.doi.org/10.1139/v06-116.

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Extracoordinate chiral hydrosilanes were generated in situ from triethoxysilane and a C2-symmetric ligand derived from bisproline 7. In the presence of a catalytic amount of ligand 7, prochiral ketones were reduced in moderate yield with moderate enantioselectivity (up to 64% ee). Alternatively, TiF4 complexes of 7 were used to provide higher enantioselectivity and with improved yields. The copper complex of ligand 7 and 29Si NMR data provide some guidance as to the key factors responsible for the observed reactivity at the silicon and at the ligand centre.Key words: extracoordinate chiral sil

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11

Yin, Yingchun, and Xin Jin. "Polyether-functionalized ionic liquid-assisted Rh-AMPP-catalyzed asymmetric hydrogenation of ketopantoyl lactone to D-(−)-pantolactone." Journal of Physics: Conference Series 2783, no. 1 (2024): 012029. http://dx.doi.org/10.1088/1742-6596/2783/1/012029.

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Abstract In this paper, the reaction of chiral Rh-AMPP catalysts for the asymmetric hydrogenation of ketopantoyl lactone to D-(-)pantolactone under a polyether guanidinium salt ionic liquid ([Me(EO)16TMG][OMs])/toluene homogeneous catalytic system was investigated. The impact of polyether ionic liquid doping on the catalytic activity and enantioselectivity was investigated. To separate and recycle chiral Rh-AMPP catalysts, a “homogeneous catalytic-liquid/solid separation” system on the basis of [Me(EO)16TMG][OMs] was constructed. The catalytic system exhibited high catalytic activity, enantios

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12

Li, Xu, Shanshan Dong, Ting Fan, Qingji Wang, and Tongfei Shi. "Role of Chiral Skeleton in Chiral Phosphoric Acids Catalyzed Asymmetric Transfer Hydrogenation: A DFT Study." Catalysts 13, no. 1 (2023): 98. http://dx.doi.org/10.3390/catal13010098.

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Chiral phosphoric acids (CPAs) have received considerable attention due to their high activity for enantioselective transformations. However, the role of various chiral skeletons of CPAs in regulating the mechanism and enantioselectivity of asymmetric transfer hydrogenation has remained unclear. Density functional theory (DFT) calculations are performed to elucidate the role of chiral skeletons on the acidity, mechanism, enantioselectivity, and kinetic stabilities of transition states (TSs) in Asymmetric Transfer Hydrogen (ATH) reaction catalyzed by five CPAs. We found that the acidity of CPAs

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13

Yagi, Yoichiro, Takatomo Kimura, and Makoto Kamezawa. "Biomolecular Chemical Simulations on Enantioselectivity and Reactivity of Lipase Enzymes to Azulene Derivatives." Natural Product Communications 17, no. 6 (2022): 1934578X2211085. http://dx.doi.org/10.1177/1934578x221108572.

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Biomolecular chemical simulations have recently become a useful research method in the fields of organic chemistry and bioscience. In the last few years, we have been focusing on the biomolecular computational simulation on lipase enzyme and ligand complexes to predict the enantioselectivity and reactivity of lipases toward non-natural organic compounds. In this paper, we describe the molecular simulations including molecular dynamics (MD) and fragment molecular orbital (FMO) calculations for the complexes of Candida antarctica lipase type A (CALA) and trifluoromethylazulene alcohol derivative

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14

Pradhan, Suresh K., Krishanlal R. Thakker, and Andrew T. McPhail. "Enantioselectivity in camphor pinacolisation." Tetrahedron Letters 28, no. 16 (1987): 1813–16. http://dx.doi.org/10.1016/s0040-4039(00)95429-7.

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15

Lämmerhofer, Michael. "Chiral separations and enantioselectivity." Journal of Chromatography A 1269 (December 2012): 1–2. http://dx.doi.org/10.1016/j.chroma.2012.10.009.

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16

Hölscher, Bernd, Norbert A Braun, Berthold Weber, Claus-Hermann Kappey, Manfred Meier, and Wilhelm Pickenhagen. "Enantioselectivity in Odor Perception." Helvetica Chimica Acta 87, no. 7 (2004): 1666–80. http://dx.doi.org/10.1002/hlca.200490151.

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17

Debashis, Sahu, Jana Kalyanashis, Sen Anik, and Ganguly Bishwajit. "Enantioselectivity of [4+2] cycloaddition between cyclopentadiene and azachalcone with DNA based hybrid catalyst in aqueous medium: A computational study." Journal of India Chemical Society Vol. 95, Dec 2018 (2018): 1551–58. https://doi.org/10.5281/zenodo.5644772.

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Computation and Simulation Unit (Analytical Discipline and Centralized Instrument Facility), CSIR-Central Salt and Marine Chemicals Research Institute, Bhavnagar-364 002, Gujarat, India Academy of Scientific and Innovative Research, CSIR-CSMCRI, Bhavnagar-364 002, Gujarat, India <em>E-mail</em>: ganguly@csmcri.res.in <em>Manuscript received online 20 November 2018, accepted 05 December 2018</em> DNA-based asymmetric catalysis is an important subset of hybrid catalysis where the chirality of DNA is utilized to induce the product enantioselectivity of metal-catalyzed reaction. The DNA-based asym

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18

Pinto, Andrea, Immacolata Serra, Diego Romano, et al. "Preparation of Sterically Demanding 2,2-Disubstituted-2-Hydroxy Acids by Enzymatic Hydrolysis." Catalysts 9, no. 2 (2019): 113. http://dx.doi.org/10.3390/catal9020113.

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Preparation of optically-pure derivatives of 2-hydroxy-2-(3-hydroxyphenyl)-2-phenylacetic acid of general structure 2 was accomplished by enzymatic hydrolysis of the correspondent esters. A screening with commercial hydrolases using the methyl ester of 2-hydroxy-2-(3-hydroxyphenyl)-2-phenylacetic acid (1a) showed that crude pig liver esterase (PLE) was the only preparation with catalytic activity. Low enantioselectivity was observed with substrates 1a–d, whereas PLE-catalysed hydrolysis of 1e proceeded with good enantioselectivity (E = 28), after optimization. Enhancement of the enantioselecti

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19

Chênevert, Robert, and Linda D'astous. "Enzyme catalysed hydrolysis of chlorophenoxypropionates." Canadian Journal of Chemistry 66, no. 5 (1988): 1219–22. http://dx.doi.org/10.1139/v88-199.

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We report on the enzymatic hydrolysis of methyl 2-phenoxypropionate and of the following chlorinated derivatives: methyl o-chloro-, m-chloro-, p-chloro-, and o,p-dichloro-2-phenoxypropionates. α-Chymotrypsin, lipase, and pig liver esterase have an R enantioselectivity whereas subtilisin has an S enantioselectivity. Enantiomeric excesses (e.e.) cover a wide range (from 5 to 100%).

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20

Li, Maolin, Yujie Yuan, Wesley Harrison, Zhengyi Zhang, and Huimin Zhao. "Asymmetric photoenzymatic incorporation of fluorinated motifs into olefins." Science 385, no. 6707 (2024): 416–21. http://dx.doi.org/10.1126/science.adk8464.

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Enzymes capable of assimilating fluorinated feedstocks are scarce. This situation poses a challenge for the biosynthesis of fluorinated compounds used in pharmaceuticals, agrochemicals, and materials. We developed a photoenzymatic hydrofluoroalkylation that integrates fluorinated motifs into olefins. The photoinduced promiscuity of flavin-dependent ene-reductases enables the generation of carbon-centered radicals from iodinated fluoroalkanes, which are directed by the photoenzyme to engage enantioselectively with olefins. This approach facilitates stereocontrol through interaction between a si

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21

Tang, Lixia, Xuechen Zhu, Huayu Zheng, Rongxiang Jiang, and Maja Majerić Elenkov. "Key Residues for Controlling Enantioselectivity of Halohydrin Dehalogenase from Arthrobacter sp. Strain AD2, Revealed by Structure-Guided Directed Evolution." Applied and Environmental Microbiology 78, no. 8 (2012): 2631–37. http://dx.doi.org/10.1128/aem.06586-11.

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ABSTRACTHalohydrin dehalogenase fromAgrobacterium radiobacterAD1 (HheC) is a valuable tool in the preparation ofRenantiomers of epoxides and β-substituted alcohols. In contrast, the halohydrin dehalogenase fromArthrobactersp. AD2 (HheA) shows a lowSenantioselectivity toward most aromatic substrates. Here, three amino acids (V136, L141, and N178) located in the two neighboring active-site loops of HheA were proposed to be the key residues for controlling enantioselectivity. They were subjected to saturation mutagenesis aimed at evolving anS-selective enzyme. This led to the selection of two out

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22

Ritter, Helmut, Antonia Stöhr та Philippe Favresse. "Oligomerization of optically active N-(4-hydroxyphenyl)mandelamide in the presence of β-cyclodextrin and the minor role of chirality". Beilstein Journal of Organic Chemistry 10 (10 жовтня 2014): 2361–66. http://dx.doi.org/10.3762/bjoc.10.246.

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The oxidative oligomerization of a chiral mandelamide derivative (N-(4-hydroxyphenyl)mandelamide, 1) was performed in the presence of horseradish peroxidase, laccase and N,N'-bis(salicylidene)ethylenediamine-iron(II) to obtain chiral oligophenols 2. The low enantioselectivity of the enzymatic catalyzed asymmetric enantiomer-differentiating oligomerizations was investigated. In addition, the poor influence of cyclodextrin on the enantioselectivity of enzymatic catalyzed asymmetric enantiomer-differentiating oligomerizations was studied.

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23

Antipov, Eugene, Art E. Cho, K. Dane Wittrup, and Alexander M. Klibanov. "Highly l and d enantioselective variants of horseradish peroxidase discovered by an ultrahigh-throughput selection method." Proceedings of the National Academy of Sciences 105, no. 46 (2008): 17694–99. http://dx.doi.org/10.1073/pnas.0809851105.

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A highly efficient selection method for enhanced enzyme enantioselectivity based on yeast surface display and fluorescence-activated cell sorting (FACS) is developed and validated. Its application to horseradish peroxidase has resulted in enzyme variants up to 2 orders of magnitude selective toward either substrate enantiomer at will. These marked improvements in enantioselectivity are demonstrated for the surface-bound and soluble enzymes and rationalized by computational docking studies.

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24

Chen, Ying-Chun, Chang-Jiang Xu, Wei Du, and Łukasz Albrecht. "Lewis Basic Amine Catalyzed Aza-Michael Reaction of Indole- and Pyrrole-3-carbaldehydes." Synthesis 52, no. 18 (2020): 2650–61. http://dx.doi.org/10.1055/s-0040-1707176.

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3-Formyl substituted indoles or pyrroles can form HOMO-raised dearomative aza-dienamine-type intermediates with secondary amines, which can undergo direct aza-Michael addition to β-trifluoromethyl enones to afford N-alkylated products efficiently, albeit with low to fair enantioselectivity. In addition, similar asymmetric aza-Michael additions of these heteroarenes and crotonaldehyde are realized under dual catalysis of chiral amines, and the adducts are obtained with moderate to good enantioselectivity.

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25

Kossler, D., and N. Cramer. "Neutral chiral cyclopentadienyl Ru(ii)Cl catalysts enable enantioselective [2+2]-cycloadditions." Chemical Science 8, no. 3 (2017): 1862–66. http://dx.doi.org/10.1039/c6sc05092a.

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A chiral version of the Cp*Ru(COD)Cl complex equipped with an atropchiral cyclopentadienyl (Cp<sup>x</sup>) ligand enables [2+2]-cycloadditions between bicyclic olefins and alkynes with excellent reactivity and enantioselectivity. A streamlined synthesis of the Cp<sup>x</sup> ligand by a C–H functionalisation approach is shown. The chloride counterion of the neutral Cp<sup>x</sup>Ru<sup>II</sup> complex is essential for enantioselectivity.

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26

Cusumano, Alexander, Tianyi Zhang, William Goddard, and Brian Stoltz. "Origins of Enhanced Enantioselectivity in the Pd-Catalyzed Decarboxylative Allylic Alkylation of N-Benzoyl Lactams." Catalysts 13, no. 9 (2023): 1258. http://dx.doi.org/10.3390/catal13091258.

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We explore the origins of the marked improvement in enantioselectivity in the inner-sphere (PHOX)Pd-catalyzed allylic alkylation of N-benzoyl lactam nucleophiles over their carbocyclic counterparts. We employ density functional theory calculations to aid in the interpretation of experimental results. Ultimately, we propose that the enhancement in enantioselectivity arises primarily from noncovalent interactions between the substrate and ligand rather than secondary substrate chelation, as previously hypothesized.

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27

Wang, Hualei, Wenyuan Gao, Huihui Sun, et al. "Protein Engineering of a Nitrilase from Burkholderia cenocepacia J2315 for Efficient and Enantioselective Production of (R)-o-Chloromandelic Acid." Applied and Environmental Microbiology 81, no. 24 (2015): 8469–77. http://dx.doi.org/10.1128/aem.02688-15.

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ABSTRACTThe nitrilase-mediated pathway has significant advantages in the production of optically pure aromatic α-hydroxy carboxylic acids. However, low enantioselectivity and activity are observed on hydrolyzingo-chloromandelonitrile to produce optically pure (R)-o-chloromandelic acid. In the present study, a protein engineering approach was successfully used to enhance the performance of nitrilase obtained fromBurkholderia cenocepaciastrain J2315 (BCJ2315) in hydrolyzingo-chloromandelonitrile. Four hot spots (T49, I113, Y199, and T310) responsible for the enantioselectivity and activity of BC

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28

Guo, Chao, Yanpu Chen, Yu Zheng, et al. "Exploring the Enantioselective Mechanism of Halohydrin Dehalogenase from Agrobacterium radiobacter AD1 by Iterative Saturation Mutagenesis." Applied and Environmental Microbiology 81, no. 8 (2015): 2919–26. http://dx.doi.org/10.1128/aem.04153-14.

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ABSTRACTHalohydrin dehalogenase fromAgrobacterium radiobacterAD1 (HheC) shows great potential in producing valuable chiral epoxides and β-substituted alcohols. The wild-type (WT) enzyme displays a highR-enantiopreference toward most aromatic substrates, whereas noS-selective HheC has been reported to date. To obtain more enantioselective enzymes, seven noncatalytic active-site residues were subjected to iterative saturation mutagenesis (ISM). After two rounds of screening aspects of both activity and enantioselectivity (E), three outstanding mutants (Thr134Val/Leu142Met, Leu142Phe/Asn176His, a

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29

Ottosson, Jenny, and Karl Hult. "Thermodynamic Analysis of Enzyme Enantioselectivity." Biochemical Society Transactions 28, no. 5 (2000): A317. http://dx.doi.org/10.1042/bst028a317b.

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30

Pieters, Roland J., Jeffrey H. Lutje Spelberg, Richard M. Kellogg, and Dick B. Janssen. "The enantioselectivity of haloalkane dehalogenases." Tetrahedron Letters 42, no. 3 (2001): 469–71. http://dx.doi.org/10.1016/s0040-4039(00)01947-x.

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31

Filippi, A., A. Giardini, S. Piccirillo, and M. Speranza. "ChemInform Abstract: Gas-Phase Enantioselectivity." ChemInform 31, no. 38 (2000): no. http://dx.doi.org/10.1002/chin.200038300.

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32

Kourist, R., B. Heinze, L. Fransson, K. Hult, and U. T. Bornscheuer. "Engineering the Enantioselectivity ofB. subtilis." Chemie Ingenieur Technik 78, no. 9 (2006): 1412. http://dx.doi.org/10.1002/cite.200650053.

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33

Shaykhutdinova, Polina, and Martin Oestreich. "Further Structural Modification of Sulfur-Stabilized Silicon Cations with Binaphthyl Backbones." Synthesis 51, no. 10 (2019): 2221–29. http://dx.doi.org/10.1055/s-0037-1610697.

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The synthesis and spectroscopic characterization of two novel cationic silicon–sulfur Lewis pairs with a chiral 4,4′-disubstituted binaphthyl silepine backbone are described. Both Lewis acids induce significant enantioselectivity in the model Diels–Alder reaction of cyclohexa-1,3-diene and chalcone but additional substitution of the binaphthyl backbone exerts a minimal effect on enantioinduction compared to previously reported Lewis acids. Another silicon cation with a chiral spirocyclic backbone induces enantioselectivity in the same range but its synthesis is laborious.

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34

Gucma, Mirosław, W. Marek Gołębiewski, and Maria Krawczyk. "Application of chiral ligands: carbohydrates, nucleoside-lanthanides and other Lewis acid complexes to control regio- and stereoselectivity of the dipolar cycloaddition reactions of nitrile oxides and esters." RSC Advances 5, no. 17 (2015): 13112–24. http://dx.doi.org/10.1039/c4ra15975f.

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35

Parfenova, Lyudmila V., Irina V. Zakirova, Pavel V. Kovyazin та ін. "Intramolecular mobility of η5-ligands in chiral zirconocene complexes and the enantioselectivity of alkene functionalization by organoaluminum compounds". Dalton Transactions 45, № 32 (2016): 12814–26. http://dx.doi.org/10.1039/c6dt01366j.

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36

Menichetti, Andrea, Sebastiano Di Pietro, Valeria Di Bussolo, Lucilla Favero, and Mauro Pineschi. "Experimental and Computational Studies Unraveling the Peculiarity of Enolizable Oxoesters in the Organocatalyzed Mannich-Type Addition to Cyclic N-Acyl Iminium Ions." Molecules 25, no. 8 (2020): 1903. http://dx.doi.org/10.3390/molecules25081903.

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γ− and δ-Oxoesters are easily available starting materials that have been sparingly used in some organocatalyzed reactions proceeding with a high enantioselectivity. In our experimentation we found that the use of these compounds as the enolizable (nucleophilic) component in organocatalyzed Mannich-type reactions using in situ-generated cyclic N-acyl iminium ions gave low diastereoselectivity and low to moderate values of enantioselectivity. This significant drop of facial selectivity with respect to simple aliphatic aldehydes has been rationalized by means of density functional theory (DFT) c

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37

Xu, En-Jie, Yan Song, Zhong-Lin Wei, et al. "Novel chiral proline-based organocatalysts with amide and thiourea–amine units for highly efficient asymmetric aldol reaction in saturated brine without additives." Canadian Journal of Chemistry 97, no. 5 (2019): 352–59. http://dx.doi.org/10.1139/cjc-2018-0352.

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A series of novel proline-based organocatalysts with amide and thiourea-amine units (7a–7f) were developed and evaluated in the asymmetric aldol reaction of 4-nitrobenzaldehyde with cyclohexanone. The organocatalyst (7c or 7d, 5 mol%) exhibited efficient catalytic activity to afford aldol products in high diastereoselectivity (up to >99:1), enantioselectivity (up to >99%), and yield (up to >96%) at 0 °C in saturated brine without adding an acid. Aldol products of benzaldehyde derivatives almost universally provide high diastereoselectivity and enantioselectivity.

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38

Godinho, Luis F., Carlos R. Reis, Pieter G. Tepper, Gerrit J. Poelarends, and Wim J. Quax. "Discovery of an Escherichia coli Esterase with High Activity and Enantioselectivity toward 1,2-O-Isopropylideneglycerol Esters." Applied and Environmental Microbiology 77, no. 17 (2011): 6094–99. http://dx.doi.org/10.1128/aem.05122-11.

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ABSTRACTEscherichia colihas been widely used as an expression host for the identification of desired biocatalysts through screening or selection assays. We have previously usedE. coliin growth selection and screening assays for identification ofBacillus subtilislipase variants (located in the periplasm) with improved activity and enantioselectivity toward 1,2-O-isopropylideneglycerol (IPG) esters. In the course of these studies, we discovered thatE. coliitself exhibits significant cytoplasmic esterase activity toward IPG esters. In order to identify the enzyme (or enzymes) responsible for this

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39

Gallarati, Simone, Raimon Fabregat, Rubén Laplaza, Sinjini Bhattacharjee, Matthew D. Wodrich, and Clemence Corminboeuf. "Reaction-based machine learning representations for predicting the enantioselectivity of organocatalysts." Chemical Science 12, no. 20 (2021): 6879–89. http://dx.doi.org/10.1039/d1sc00482d.

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40

Bakr, Brandon W., and C. David Sherrill. "Analysis of transition state stabilization by non-covalent interactions in organocatalysis: application of atomic and functional-group partitioned symmetry-adapted perturbation theory to the addition of organoboron reagents to fluoroketones." Physical Chemistry Chemical Physics 20, no. 27 (2018): 18241–51. http://dx.doi.org/10.1039/c8cp02029a.

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41

Kean, Suzanna D., Christopher J. Easton, Stephen F. Lincoln, and David Parker. "A Preparative and Solution Study of a Modified b-Cyclodextrin and its Europium(III) Complex, and their Interactions with Racemic Amino Acid Anions." Australian Journal of Chemistry 54, no. 8 (2001): 535. http://dx.doi.org/10.1071/ch01102.

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The synthesis and characterization of 6A-deoxy-6A-(1,4,7-tri(carboxylatomethyl)-1,4,7,10-tetraazacyclododecan-10-yl)-β-cyclodextrin (1b) are reported. A fluorescence lifetime study of its Eu3+ complex (1c) is consistent with one water coordinating Eu3+ in addition to hepta-coordination by (1b). 1H NMR studies are consistent with (1b) forming host–guest complexes with (R/S)-histidinate (2a), (R/S)-tyrosinate (2b), (R/S)-phenylalaninate (2c), and (R/S)-tryptophanate (2d), with enantioselectivity shown for (2b). Similar studies are consistent with (1c) complexing (2a–d), with enantioselectivity s

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42

Illesinghe, Jayamini, Richard Ebeling, Brett Ferguson, et al. "An Evaluation of Some Hindered Diamines as Chiral Modifiers of Metal-Promoted Reactions." Australian Journal of Chemistry 57, no. 2 (2004): 167. http://dx.doi.org/10.1071/ch03238.

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Diamino analogues of the C2-symmetric chiral diphosphine ligands DuPHOS and BPE have been prepared and evaluated as chiral modifiers of the osmium tetraoxide dihydroxylation of stilbene. NMR experiments showed that these ligands were too bulky to coordinate to osmium. Less hindered analogues of these ligands were prepared and some were shown to act as ligands in dihydroxylation reactions but with poor enantioselectivity (e.e. < 10%). The diamines have also been briefly evaluated as ligands in rhodium-catalyzed hydroformylation and copper-catalyzed phenolic coupling reactions. Once again, on

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Liu, Chunxiao, Bo Wang, Jingling Diao, and Zhiqiang Zhou. "Enantioselective toxicity and bioaccumulation of epoxiconazole enantiomers to the green alga Scenedesmus obliquus." RSC Advances 6, no. 64 (2016): 59842–50. http://dx.doi.org/10.1039/c6ra12617k.

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Leśniarek, Aleksandra, Anna Chojnacka, and Witold Gładkowski. "Application of Lecitase® Ultra-Catalyzed Hydrolysis to the Kinetic Resolution of (E)-4-phenylbut-3-en-2-yl Esters." Catalysts 8, no. 10 (2018): 423. http://dx.doi.org/10.3390/catal8100423.

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The possibility of using Lecitase® Ultra as a novel alternative biocatalyst for the kinetic resolution of model racemic allyl esters of (E)-4-phenylbut-3-en-3-ol: Acetate (4a) and propionate (4b) through their enantioselective hydrolysis was investigated. Reaction afforded (+)-(R)-alcohol (3) and unreacted (−)-(S)-ester (4a or 4b). Hydrolysis of propionate 4b proceeded with higher enantioselectivity than acetate 4a. (R)-Alcohol (3) with highest enantiomeric excess (93–99%) was obtained at 20–30 °C by hydrolysis of propionate 4b, while the highest optical purity of unreacted substrate was obser

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Kozma, Viktória, Zsolt Szakonyi та György Szőllősi. "β-Amino Acid Organocatalysts in the Asymmetric Michael Addition of Isobutyraldehyde to N-Substituted Maleimides". Catalysts 12, № 9 (2022): 992. http://dx.doi.org/10.3390/catal12090992.

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Asymmetric Michael additions of carbonyl compounds to N-substituted maleimides are among the most convenient reactions to prepare optically pure succinimide building blocks. Although a few β-amino acids were found to be highly efficient organocatalysts in the addition of α-branched aldehydes, the effect of their structure on the results of these reactions has not yet been investigated. In the present study, we disclose several unexpected and interesting structural effects of aliphatic and cycloaliphatic β-amino acids obtained in the enantioselective conjugate addition of isobutyraldehyde to N-

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Brand, Stephen K., Joel E. Schmidt, Michael W. Deem, et al. "Enantiomerically enriched, polycrystalline molecular sieves." Proceedings of the National Academy of Sciences 114, no. 20 (2017): 5101–6. http://dx.doi.org/10.1073/pnas.1704638114.

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Zeolite and zeolite-like molecular sieves are being used in a large number of applications such as adsorption and catalysis. Achievement of the long-standing goal of creating a chiral, polycrystalline molecular sieve with bulk enantioenrichment would enable these materials to perform enantioselective functions. Here, we report the synthesis of enantiomerically enriched samples of a molecular sieve. Enantiopure organic structure directing agents are designed with the assistance of computational methods and used to synthesize enantioenriched, polycrystalline molecular sieve samples of either ena

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Li, Jiacheng, Jianjiong Li, Yunfeng Cui, et al. "Asymmetric Synthesis of Both Enantiomers of Dimethyl 2-Methylsuccinate by the Ene-Reductase-Catalyzed Reduction at High Substrate Concentration." Catalysts 12, no. 10 (2022): 1133. http://dx.doi.org/10.3390/catal12101133.

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Chiral dimethyl 2-methylsuccinate (1) is a very important building block for the manufacturing of many active pharmaceutical ingredients and fine chemicals. The asymmetric reduction of C=C double bond of dimethyl citraconate (2), dimethyl mesaconate (3) or dimethyl itaconate (4) by ene-reductases (ERs) represents an attractive straightforward approach, but lack of high-performance ERs, especially (S)-selective ones, has limited implementing this method to prepare the optically pure dimethyl 2-methylsuccinate. Herein, three ERs (Bac-OYE1 from Bacillus sp., SeER from Saccharomyces eubayanus and

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Xiao, Qiong, Yifan Tang, Ping Xie та Dali Yin. "Asymmetric amination of α,α-dialkyl substituted aldehydes catalyzed by a simple chiral primary amino acid and its application to the preparation of a S1P1 agonist". RSC Advances 9, № 57 (2019): 33497–505. http://dx.doi.org/10.1039/c9ra06210f.

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Mitra, Mainak, Olaf Cusso, Satish S. Bhat, et al. "Highly enantioselective epoxidation of olefins by H2O2 catalyzed by a non-heme Fe(ii) catalyst of a chiral tetradentate ligand." Dalton Transactions 48, no. 18 (2019): 6123–31. http://dx.doi.org/10.1039/c8dt04449j.

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Doyle, Michael P., and Wenhao Hu. "Enantioselectivity for catalytic cyclopropanation with diazomalonates." Arkivoc 2003, no. 7 (2003): 15–22. http://dx.doi.org/10.3998/ark.5550190.0004.703.

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