cas 25779-13-9, (S)-(+)-1-Phenyl-1,2-ethanediol

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Marked improvement in the asymmetric reduction of 2-hydroxyacetophenone with mut-AcCR in a biphasic system
(S)-1-Phenyl-1,2-ethanediol (PED) is a vital chiral block in specialty chemical industries. The biotransformation of 2-hydroxyacetophenone (2-HAP) to (S)-PED was conducted successfully catalyzed with BL21(DE3)(pETDuet-gst-mut-accr-gdh) which harboring a c
Chao, Peng,Li, Dong-Li,Lou, Wen-Yong,Wang, Yao-Ying,Wei, Ping,Zong, Min-Hua,Zou, Qing-Jian
(2020)
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Enantioselective catalysis using planar chiral η6-arene chromium complexes: 1,2-Diols as cycloaddition catalysts
A highly selective Diels-Alder catalyst has been prepared from a commercially available tetrahydronaphthalene diol. Stereocontrol is greatly enhanced by introduction of a planar chiral arene chromium tricarbonyl group, achieved by face selective complexat
Jones, Graham B.,Guzel, Mustafa,Heaton, Steven B.
p. 4303 - 4320
(2000)
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Coexpression of a carbonyl reductase and glucose 6-phosphate dehydrogenase in Pichia pastoris improves the production of (S)-1-phenyl-1,2-ethanediol
To develop an efficient biocatalyst to produce optically active (S)-phenyl ethanediol (PED), a carbonyl reductase SCRII and glucose 6-phosphate dehydrogenase were coexpressed intracellularly in Pichia pastoris. The recombinant enzyme PpSCRII was purified
Geng, Yawei,Zhang, Rongzhen,Xu, Yan,Wang, Shanshan,Sha, Chong,Xiao, Rong
p. 172 - 178
(2011)
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Method for synthesizing chiral 1,2-diol compound
The invention relates to a method for synthesizing a chiral 1,2-diol compound, which comprises the following steps: sequentially adding a cobalt catalyst, a ligand, alpha-hydroxy ketone, an organic solvent and silane into a reaction system at 20-30 DEG C in a nitrogen atmosphere, then stirring the mixture, and carrying out column chromatography separation on the obtained product to obtain the chiral 1,2-diol compound. The high-yield cobalt catalyst in the earth crust is used, meanwhile, cheap silane (PMHS, 500 g/298 yuan) is used as a reducing agent, the asymmetric reduction reaction of alpha-hydroxy ketone can be efficiently achieved under the mild condition, and the chiral 1,2-diol compound with high yield and optical activity is obtained. Moreover, through the creative labor of the inventor, the reaction yield can reach 99%, and meanwhile, the content of the target product in the generated reaction product is 99% (namely, the yield is 99%, 99% ee).
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(2021/07/21)

Tridentate nitrogen phosphine ligand containing arylamine NH as well as preparation method and application thereof
The invention discloses a tridentate nitrogen phosphine ligand containing arylamine NH as well as a preparation method and application thereof, and belongs to the technical field of organic synthesis. The tridentate nitrogen phosphine ligand disclosed by the invention is the first case of tridentate nitrogen phosphine ligand containing not only a quinoline amine structure but also chiral ferrocene at present, a noble metal complex of the type of ligand shows good selectivity and extremely high catalytic activity in an asymmetric hydrogenation reaction, meanwhile, a cheap metal complex of the ligand can also show good selectivity and catalytic activity in the asymmetric hydrogenation reaction, and is very easy to modify in the aspects of electronic effect and space structure, so that the ligand has huge potential application value. A catalyst formed by the ligand and a transition metal complex can be used for catalyzing various reactions, can be used for synthesizing various drugs, and has important industrial application value.
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Paragraph 0117-0120

(2021/06/26)

Application of the redox system of Nocardia corallina B-276 in the enantioselective biotransformation of ketones and alcohols
The aim of this research was to evaluate the redox system of Nocardia corallina B-276 in the biotransformation of 1-phenyl-1-propanone (1a), 2-hydroxy-1-phenylethanone (2a) and methyl (2-chlorophenyl)(oxo)acetate (3a) into 1-phenylpropan-1-ol (1b), 1-phenyl-1,2-ethanediol (2b) and methyl (2-chlorophenyl)(hydroxy)acetate (3b). The biomass of N. corallina was obtained in a liquid medium with an initial pH of 8.50, but the pH changed during the 96 h of the culture media, the final pH was between 4.74 and 7.62. The N. corallina biomass biocatalyzed the enantioselective reduction of 1a–3a to the corresponding alcohols. Whereas, during the process of oxidation of the rac-alcohols 1b–3b, 1b was oxidized in enantioselective way, the oxidation of 2b was not selective, but 3b was biotransformed mainly to (R)-3b. These results are indicative that N. corallina produced reductases and oxidases, whereby the biocatalytic activity was influenced by the final pH of the culture media, the reaction time and structure of the substrate.
Alvarez, Norberto Manjarrez,Pérez Méndez, Herminia I.,Oba, Aida Solís,Cabello, Lucía Ortega,Lara Carvajal, María T.,Valencia Ledezma, Omar E.,Martínez-Casares, Rubria M.
p. 279 - 290
(2020/06/01)

Highly regio- and enantio-selective hydrolysis of two racemic epoxides by GmEH3, a novel epoxide hydrolase from Glycine max
A novel epoxide hydrolase from Glycine max, designated GmEH3, was excavated based on the computer-aided analysis. Then, gmeh3, a GmEH3-encoding gene, was cloned and successfully expressed in E. coli Rosetta(DE3). Among the ten investigated rac-epoxides, GmEH3 possessed the highest and best complementary regioselectivities (regioselectivity coefficients, αS = 93.7% and βR = 97.2%) in the asymmetric hydrolysis of rac-m-chlorostyrene oxide (5a), and the highest enantioselectivity (enantiomeric ratio, E = 55.6) towards rac-phenyl glycidyl ether (7a). The catalytic efficiency (kcatS/KmS = 2.50 mM?1 s?1) of purified GmEH3 for (S)-5a was slightly higher than that (kcatR/KmR = 1.52 mM?1 s?1) for (R)-5a, whereas the kcat/Km (5.16 mM?1 s?1) for (S)-7a was much higher than that (0.09 mM?1 s?1) for (R)-7a. Using 200 mg/mL wet cells of E. coli/gmeh3 as the biocatalyst, the scale-up enantioconvergent hydrolysis of 150 mM rac-5a at 25 °C for 1.5 h afforded (R)-5b with 90.2% eep and 95.4% yieldp, while the kinetic resolution of 500 mM rac-7a for 2.5 h retained (R)-7a with over 99% ees and 43.2% yields. Furthermore, the sources of high regiocomplementarity of GmEH3 for (S)- and (R)-5a as well as high enantioselectivity towards rac-7a were analyzed via molecular docking (MD) simulation.
Zhang, Chen,Li, Chuang,Zhu, Xiu-xiu,Liu, You-yi,Zhao, Jun,Wu, Min-chen
p. 2795 - 2803
(2020/09/01)

Absolute stereochemical determination of 1,2-diols via complexation with dinaphthyl borinic acid
Rapid derivatization of chiral 1,2-diols with dinaphthyl borinic acid (DBA) leads to a cyclic boronate, enabling the absolute stereochemical prediction via exciton-coupled circular dichroic (ECCD) of the naphthyl groups. Aryl- and alkyl-substituted 1,2-diols derivatized with DBA yield a predictable ECCD, which is also in agreement with theoretical predictions derived from computationally minimized structures.
Torabi Kohlbouni, Saeedeh,Sarkar, Aritra,Zhang, Jun,Li, Xiaoyong,Borhan, Babak
supporting information
p. 817 - 823
(2020/03/26)

Diversity and oriented synthesis of clopidogrel drug derivatives
An efficient synthetic route has been developed for the synthesis of new clopidogrel drug derivatives. Key step of this method is to replacement of mesyl protected alcohol group with various aliphatic amines in presence of base. Various clopidogrel drug d
Tejeswararao
p. 3007 - 3011
(2021/01/06)

Reprogramming Epoxide Hydrolase to Improve Enantioconvergence in Hydrolysis of Styrene Oxide Scaffolds
Enantioconvergent hydrolysis by epoxide hydrolase is a promising method for the synthesis of important vicinal diols. However, the poor regioselectivity of the naturally occurring enzymes results in low enantioconvergence in the enzymatic hydrolysis of styrene oxides. Herein, modulated residue No. 263 was redesigned based on structural information and a smart variant library was constructed by site-directed modification using an “optimized amino acid alphabet” to improve the regioselectivity of epoxide hydrolase from Vigna radiata (VrEH2). The regioselectivity coefficient (r) of variant M263Q for the R-isomer of meta-substituted styrene oxides was improved 40–63-fold, and variant M263V also exhibited higher regioselectivity towards the R-isomer of para-substituted styrene oxides compared with the wild type, which resulted in improved enantioconvergence in hydrolysis of styrene oxide scaffolds. Structural insight showed the crucial role of residue No. 263 in modulating the substrate binding conformation by altering the binding surroundings. Furthermore, increased differences in the attacking distance between nucleophilic residue Asp101 and the two carbon atoms of the epoxide ring provided evidence for improved regioselectivity. Several high-value vicinal diols were readily synthesized (>88% yield, 90%–98% ee) by enantioconvergent hydrolysis using the reprogrammed variants. These findings provide a successful strategy for enhancing the enantioconvergence of native epoxide hydrolases through key single-site mutation and more powerful enzyme tools for the enantioconvergent hydrolysis of styrene oxide scaffolds into single (R)-enantiomers of chiral vicinal diols. (Figure presented.).
Li, Fu-Long,Qiu, Yan-Yan,Zheng, Yu-Cong,Chen, Fei-Fei,Kong, Xu–Dong,Xu, Jian-He,Yu, Hui-Lei
supporting information
p. 4699 - 4706
(2020/09/21)

An easy and low-cost method of embedding chiral molecules in metal-organic frameworks for enantioseparation
A facile method, post-synthetic exchange of modulators (PSEm), has been demonstrated here to prepare chiral metal-organic frameworks for enantioseparation. Based on this method, three chiral porous Zr-based metal-organic frameworks have been prepared through exchanging the coordinated modulators on metal clusters of MOFs with commercially available chiral carboxylic acid molecules. In addition, the obtained materials show enantioselectivity toward three different enantiomers, which presents a proof of concept for the design of MOF materials for enantioseparation by an easy and low-cost method. This journal is
Cao, Rong,Fang, Zhi-Bin,Hu, Xiao-Jing,Huang, Ge,Liu, Tian-Fu,Zhang, Shuo
supporting information
p. 7459 - 7462
(2020/07/15)

Enantiocomplementary C–H Bond Hydroxylation Combining Photo-Catalysis and Whole-Cell Biocatalysis in a One-Pot Cascade Process
Enantiocomplementary hydroxylation of alkyl aromatics through a one-pot photo-biocatalytic cascade reaction is described. The photoredox process is implemented in aqueous phase with O2 as oxidant and the subsequent (R)- or (S)-selective bioreduction is performed by whole cell system without the addition of the expensive cofactor (NADPH). This mild, operationally simple protocol transforms a wide variety of readily available aromatic compounds into valuable chiral alcohols with high yield (up to 90 %) and stereoselectivity (up to 99 %), thereby displaying important potentials in organic synthesis.
Peng, Yongzhen,Li, Danyang,Fan, Jiajie,Xu, Weihua,Xu, Jian,Yu, Huilei,Lin, Xianfu,Wu, Qi
supporting information
p. 821 - 825
(2020/02/20)

Cleavage of N-H Bond of Ammonia via Metal-Ligand Cooperation Enables Rational Design of a Conceptually New Noyori-Ikariya Catalyst
The asymmetric transfer hydrogenation (ATH) of ketones/imines with Noyori-Ikariya catalyst represents an important reaction in both academia and fine chemical industry. The method allows for the preparation of chiral secondary alcohols/amines with very good to excellent optical purities. Remarkably, the same chiral Noyori-Ikariya complex is also a precatalyst for a wide range of other chemo- and stereoselective reductive and oxidative transformations. Among them are enantioselective sulfonamidation of acrylates (intramolecular aza-Michael reaction) and carboxylation of indoles with CO2. Development of these catalytic reactions has been inspired by the realized cleavage of the N-H bond of sulfonamides and indoles by the 16e- amido derivative of the 18e- precatalyst via metal-ligand cooperation (MLC). This paper summarizes our efforts to investigate N-H bond cleavage of gaseous ammonia in solution via MLC and reports the serendipitous discovery of a new class of chiral tridentate I3[N,N′,N″] Ru and Ir metallacycles, derivatives of the famous M-FsDPEN catalysts (M = Ru, Ir). The protonation of these metallacycles by strong acids containing weakly coordinating (chiral) anions generates ionic complexes, which were identified as conceptually novel Noyori-Ikariya precatalysts. For example, the ATH of aromatic ketones with some of these complexes proceeds with up to 99% ee.
Dub, Pavel A.,Matsunami, Asuka,Kuwata, Shigeki,Kayaki, Yoshihito
p. 2661 - 2677
(2019/02/14)

Enantioselective Resolution Copolymerization of Racemic Epoxides and Anhydrides: Efficient Approach for Stereoregular Polyesters and Chiral Epoxides
Herein we report an efficient strategy for preparing isotactic polyesters and chiral epoxides via enantioselective resolution copolymerization of racemic terminal epoxides with anhydrides, mediated by enantiopure bimetallic complexes in conjunction with a nucleophilic cocatalyst. The chirality of both the axial linker and the diamine backbones of the ligand are responsible for the chiral induction of this kinetic resolution copolymerization process. The catalyst systems exhibit exceptional levels of enantioselectivity with a kinetic resolution coefficient exceeding 300 for various racemic epoxides, affording highly isotactic copolymers (selectivity factors of more than 300) with a completely alternating structure and low polydispersity index. Most of the produced isotactic polyesters are typical semicrystalline materials with melting temperatures in the range from 77 to 160 °C.
Li, Jie,Ren, Bai-Hao,Wan, Zhao-Qian,Chen, Shi-Yu,Liu, Ye,Ren, Wei-Min,Lu, Xiao-Bing
supporting information
p. 8937 - 8942
(2019/06/11)

Structurally Defined α-Tetralol-Based Chiral Hypervalent Iodine Reagents
A novel class of chiral hypervalent iodine reagents containing an α-tetralol scaffold is introduced. Iodine triacetate is employed in a key step as a highly selective and efficient iodinating reagent for a short and convenient synthesis of iodine(III) derivatives. Solid-state X-ray analyses offer valuable structural information, while reactivities and stereoselectivities are investigated in three model reactions.
Hokamp, Tobias,Wirth, Thomas
p. 8674 - 8682
(2019/07/03)

Aromatic Donor-Acceptor Interaction-Based Co(III)-salen Self-Assemblies and Their Applications in Asymmetric Ring Opening of Epoxides
Aromatic donor-acceptor interaction as the driving force to assemble cooperative catalysts is described. Pyrene/naphthalenediimide functionalized Co(III)-salen complexes self-assembled into bimetallic catalysts through aromatic donor-acceptor interactions and showed high catalytic activity and selectivity in the asymmetric ring opening of various epoxides. Control experiments, nuclear magnetic resonance (NMR) spectroscopy titrations, mass spectrometry measurement, and X-ray crystal structure analysis confirmed that the catalysts assembled based on the aromatic donor-acceptor interaction, which can be a valuable noncovalent interaction in supramolecular catalyst development.
Liang, Jian,Soucie, Luke N.,Blechschmidt, Daniel R.,Yoder, Aaron,Gustafson, Addie,Liu, Yu
supporting information
p. 513 - 518
(2019/01/14)

Significantly enhancing the biocatalytic synthesis of chiral alcohols by semi-rationally engineering an anti-Prelog carbonyl reductase from Acetobacter sp. CCTCC M209061
Chiral alcohols and their derivatives are vital building blocks to synthesize pharmaceutical drugs and high-valued chemicals. Wild-type carbonyl reductase AcCR from Acetobacter sp. has ideal enantioselectivity toward 11 prochiral substrates (e.e.>99%) but poor activity. In this work, a semi-rational engineering was performed to enhance the activity of AcCR. Fortunately, three positive double-mutants (mut-E144A/G152 L, mut-G152 L/Y189 N, and mut-I147 V/G152 L) with specific activity 17–61 folds higher than that of enzyme without modified were achieved. Kinetic studies suggested that the catalytic efficiencies (kcat/Km) of these mutants were also well enhanced. Finally, these modified mut-AcCRs were successfully applied in asymmetric reductions of 11 structurally diverse prochiral substrates (200 mM) with excellent product yields (76.8%–99.1%) and enantiomeric excess (e.e.>99%), which provides an alternative strategy for efficient synthesis of chiral alcohols for pharmaceuticals industry with ideal yield and enantioselectivity.
Wei, Ping,Guo, Ze-Wang,Wu, Xiao-Ling,Liang, Shan,Ou, Xiao-Yang,Xu, Pei,Zong, Min-Hua,Yang, Ji-Guo,Lou, Wen-Yong
(2019/09/18)

Enantiocomplementary decarboxylative hydroxylation combining photocatalysis and whole-cell biocatalysis in a one-pot cascade process
Designing a green, highly efficient and stereoselective catalytic system to generate valuable enantioenriched products is a long-standing goal in green chemistry. Here, we report a one-pot cascade combining photocatalysts with (R)- or (S)-selective ketoreductases for the decarboxylative carbonylation of carboxylic acids and the subsequent bioreduction to generate valuable chiral alcohols. Using this approach, various chiral alcohols with complementary (R)- or (S)-configurations were prepared with good yields (up to 93%) and excellent stereoselectivity (up to 99% ee). Such a photochemo-enzymatic one-pot whole-cell process combines the advantages of both photocatalysts and enzyme catalysts and provides a mild, green, metal-free and highly stereoselective alternative in asymmetric decarboxylative hydroxylation reactions.
Xu, Jian,Arkin, Mamatjan,Peng, Yongzhen,Xu, Weihua,Yu, Huilei,Lin, Xianfu,Wu, Qi
supporting information
p. 1907 - 1911
(2019/04/27)

Highly regio- And stereoselective synthesis of cyclic carbonates from biomass-derived polyols: Via organocatalytic cascade reaction
The cascade reaction of CO2, vicinal diols, and propargylic alcohol, was firstly achieved by dual Lewis base (LB) organocatalytic systems involving LB-CO2 adducts and commercially available organic amines. This methodology could overcome the chemical inertness of CO2, providing an alternative route to various functionalized five-membered cyclic carbonates in moderate to high yields under mild reaction conditions (25 °C, 1.0 atm of CO2). More importantly, this method could also be applied for facile and efficient synthesis of chiral polycyclic carbonates from biomass-derived polyols with complete configuration retention of chiral centers. This study provides an environment-friendly, scalable and cost effective protocol to construct value-added cyclic carbonates with multi-functional groups and chiral centers.
Zhou, Hui,Zhang, Hui,Mu, Sen,Zhang, Wen-Zhen,Ren, Wei-Min,Lu, Xiao-Bing
supporting information
p. 6335 - 6341
(2019/12/03)

One-Pot Three-Step Consecutive Transformation of L-α-Amino Acids to (R)- and (S)-Vicinal 1,2-Diols via Combined Chemical and Biocatalytic Process
Optically pure vicinal 1,2-diols are versatile chiral building blocks in the fine chemical and pharmaceutical industries. L-α-amino acid is a good feedstock source for high value-added product production since it is inexpensive and renewable. However, conversion of L-α-amino acids to enantioenriched vicinal 1,2-diols remains a significant challenge. In this study, combining a simple chemical process and a three-enzyme cascade biocatalysis system, we have successfully implemented a one-pot sequential process for the transformation of L-α-amino acids into enantiopure vicinal 1,2-diols in aqueous medium. Firstly, the NaBH4-H2SO4 system converted L-α-amino acids to (S)-amino alcohols via amino acid carboxyl reduction. Secondly, the three-enzyme (transaminase, carbonyl reductase and glucose dehydrogenase) cascade biocatalysis system converted amino alcohols to enantiopure vicinal 1,2-diols via amino alcohol deamination, α-hydroxy ketone asymmetric reduction and cofactor regeneration. Taking advantage of the two different reaction systems, chiral vicinal 1,2-diols could be obtained from L-α-amino acids with high yields (69–90 %) and excellent ee values (91–>99 % ee).
Zhang, Jian-Dong,Zhao, Jian-Wei,Gao, Li-Li,Zhao, Jing,Chang, Hong-Hong,Wei, Wen-Long
p. 5032 - 5037
(2019/10/28)

Well-confined polyoxometalate-ionic liquid in silicic framework for environmentally friendly asymmetric di-hydroxylation of olefins
Chiral 1,2-diols with a high yield could be directly prepared from asymmetric di-hydroxylation of olefins via an eco-friendly and enduring catalyst, in which abundant "chiral pools" of polyoxometalate-ionic liquid were target-designed into the silicic framework (POM-ILS) and well stabilized in aqueous media.
Liang, Dong,Wang, Yan,Wang, Sifan,Song, Chengkun,Shi, Yonghe,Liu, Qinghao,Zhu, Hailin,Li, Xia,Liu, Laishuan,Zhu, Na
p. 6102 - 6106
(2019/03/12)

Calix[8]arene as New Platform for Cobalt-Salen Complexes Immobilization and Use in Hydrolytic Kinetic Resolution of Epoxides
Eight cobalt-salen complexes have been covalently attached to a calix[8]arene platform through a flexible linker by a procedure employing Click chemistry. The corresponding well-defined catalyst proved its efficiency in the hydrolytic kinetic resolution (HKR) of various epoxides through an operative bimetallic cooperative activation, demonstrating highly enhanced activity when compared to its monomeric analogue. As an insoluble complex, this multisite cobalt-salen catalyst could be easily recovered and reused in successive catalytic runs. Products were isolated by a simple filtration with virtually no cobalt traces and without requiring a prior purification by flash chromatography.
Abdellah, Ibrahim,Martini, Cyril,Dos Santos, Amandine,Dragoe, Diana,Guérineau, Vincent,Huc, Vincent,Schulz, Emmanuelle
p. 4761 - 4767
(2018/10/02)

Lewis pairs for ring-opening alternating copolymerization of cyclic anhydrides and epoxides
A simple and highly active catalytic process for ring-opening alternating copolymerization (ROAC) of cyclic anhydrides and epoxides still remains a key challenge. Herein, we have described an effective group of versatile and low-toxic zinc dicarbyl/amine Lewis pairs for the ROAC. The facile route showed a high catalytic activity (TOF ≤ 210 h-1 at 110 °C) and perfectly alternating selectivity (>99%). An unexpected highly regioselective ring-opening of asymmetric epoxides (PO, ECH and SO) was also achieved by the combination of zinc alkyls (or aryls) and amines. Of note, deprotonation side reaction of α-H of anhydrides with organic bases was uncovered, and subsequently was inhibited by using nonpolar solvents and Lewis acid/base pairs. Thus, an array of polyesters was synthesized by the coupling of various anhydrides (PA, CHA, SA and NA) and epoxides (CHO, PO, ECH and SO) using the same Lewis pairs. Furthermore, variable temperature 1H NMR spectral and MALDI TOF MS analyses were performed to understand the possible mechanism and microstructure. The experimental results indicated that zwitterionic alkoxide and carboxylate intermediates alternately formed to enhance the ester repeat units in chain initiation and propagation. This work provides a simple and green catalytic strategy to prepare diversified polyesters from the ROAC process of cyclic anhydrides and epoxides with considerable catalytic activity and alternating selectivity.
Ji, He-Yuan,Wang, Bin,Pan, Li,Li, Yue-Sheng
supporting information
p. 641 - 648
(2018/02/14)

Molecular Basis for the High Activity and Enantioselectivity of the Carbonyl Reductase from Sporobolomyces salmonicolor toward α-Haloacetophenones
In an effort to develop a practical method for the synthesis of optically pure 2,2,2-trifluoro-1-phenylethanol, we found that the carbonyl reductase (SSCR) from Sporobolomyces salmonicolor showed excellent activity and enantioselectivity toward the halogenated acetophenones. Especially, SSCR exhibited more than 1000 times higher activity toward α,α,α-trifluoroacetophenone than unsubstituted acetophenone, a strikingly different observation from the previously well-studied alcohol dehydrogenase (LBADH) from Lactobacillus brevis. Enzyme-substrate docking and site-directed mutagenesis studies revealed the molecular basis for the high enzyme activity and enantioselectivity of SSCR toward the α-halogenated acetophenones. The hydrogen bond of the Asn207 side chain with the substrate halogen atom and the XH/π interaction of the substrate phenyl group with the side chains of Ser222/Thr223 resulted in the formation of the highly reactive conformation of α-halogenated acetophenones in the active site of the enzyme. (S)-2,2,2-Trifluoro-1-phenylethanol was prepared in excellent isolated yield and enantiomeric excess from the reduction of α,α,α-trifluoroacetophenone with mutant T209A. These results suggest that tuning the interactions between the halogen atoms/phenyl group of the substrate and the amino acid residues of the enzyme would lead to valuable mutants for the practical synthesis of β-haloalcohols.
Chen, Xi,Zhang, Hongliu,Feng, Jinhui,Wu, Qiaqing,Zhu, Dunming
p. 3525 - 3531
(2018/04/14)

Chiral Ion-Pair Organocatalyst-Promoted Efficient Enantio-selective Reduction of α-Hydroxy Ketones
The enantioselective reduction of α-hydroxy ketones with catecholborane has been developed employing 5 mol% of an 1,1′-bi-2-naphthol (BINOL)-derived ion-pair organocatalyst. This methodology provides a straightforward access to the corresponding aromatic 1,2-diols in high yields (up to 90%) with excellent enantioselectivities (up to 97%). Furthermore, the α-amino ketones also could be reduced with moderate ee values under mild reaction condition. (Figure presented.).
Zhang, Yiliang,He, Li,Shi, Lei
p. 1926 - 1931
(2018/03/27)

Accessible Bifunctional Oxy-Tethered Ruthenium(II) Catalysts for Asymmetric Transfer Hydrogenation
A concise synthesis of new oxy-tethered ruthenium complexes effective for the asymmetric transfer hydrogenation of aromatic ketones is described. The oxy-tether was constructed via a defluorinative etherification arising from an intramolecular nucleophilic substitution of a perfluorinated phenylsulfonyl substituent. The obtained tethered complexes exhibited desirable catalytic activity and selectivity, especially in the asymmetric transfer hydrogenation of functionalized aromatic ketones. The robustness and rigidity of the tether contribute to their superior catalytic performance relative to the nontethered prototype complex.
Matsunami, Asuka,Ikeda, Marika,Nakamura, Hitomi,Yoshida, Minori,Kuwata, Shigeki,Kayaki, Yoshihito
supporting information
p. 5213 - 5218
(2018/09/13)

Multicore Artificial Metalloenzymes Derived from Acylated Proteins as Catalysts for the Enantioselective Dihydroxylation and Epoxidation of Styrene Derivatives
Artificial metalloenzymes (AME′s) are an interesting class of selective catalysts, where the chiral environment of proteins is used as chiral ligand for a catalytic metal. Commonly, the active site of an enzyme is modified with a catalytically active metal. Here we present an approach, where the commercial proteins lysozyme (LYS) and bovine serum albumin (BSA) can be converted into highly active and enantioselective AME′s. This is achieved by acylation of the proteins primary amino groups, which affords the metal salts in the core of the protein. A series of differently acylated LYS and BSA were reacted with K2OsO2(OH)4, RuCl3, and Ti(OMe)4, respectively, and the conjugates were tested for their catalytic activity in dihydroxylation and epoxidation of styrene and its derivatives. The best suited system for dihydroxylation is fully acetylated LYS conjugated with K2OsO2(OH)4, which converts styrene to 1,2-phenylethanediol with an enantioselectivity of 95 % ee (S). BSA fully acylated with hexanoic acid and conjugated with three moles RuCl3 per mole protein shows the highest ee values for the conversion of styrene to the respective epoxide with enenatioselectivities of over 80 % ee (R), a TON of more than 2500 and a yield of up to 78 % within 24 h at 40 °C. LYS has two favored selective binding sites for the metal catalyst and BSA has even three. The AME′s with titanate in the active center invert the enantioselectivity of styrene epoxidation.
Leurs, Melanie,Dorn, Bjoern,Wilhelm, Sascha,Manisegaran, Magiliny,Tiller, Joerg. C.
supporting information
p. 10859 - 10867
(2018/08/03)

Semirational Engineering of the Naphthalene Dioxygenase from Pseudomonas sp. NCIB 9816-4 towards Selective Asymmetric Dihydroxylation
Enzyme-catalyzed asymmetric dihydroxylation is a powerful tool for the selective oxyfunctionalization of various organic compounds. By applying Rieske non-heme dioxygenases (ROs), molecular oxygen and a reduction equivalent are needed for the generation of vicinal cis-diols. We report a comprehensive mutagenesis study of the active site of the naphthalene dioxygenase from Pseudomonas sp. NCIB 9816-4 comprising 62 variants. We aimed to understand the important structure–function relationships by investigating different substituted arene substrates and the geometry of the active site. Introducing single-point mutations at positions F202, A206, V260, H295, F352, and L307 resulted in drastic shifts in the reaction specificity, regioselectivity, and stereoselectivity (≥90 %) while maintaining the residual activity towards the natural substrate naphthalene.
Halder, Julia M.,Nestl, Bettina M.,Hauer, Bernhard
p. 178 - 182
(2017/12/26)

Enantioselective Dihydroxylation of Alkenes Catalyzed by 1,4-Bis(9-O-dihydroquinidinyl)phthalazine-Modified Binaphthyl–Osmium Nanoparticles
A series of unprecedented binaphthyl–osmium nanoparticles (OsNPs) with chiral modifiers were applied in the heterogeneous asymmetric dihydroxylation of alkenes. A remarkable size effect of the OsNPs, depending on the density of the covalent organic shells, on the reactivity and enantioselectivity of the dihydroxylation reaction was revealed. Successful recycling of the OsNPs was also demonstrated and high reaction efficiency and enantioselectivity were maintained.
Zhu, Jie,Sun, Xiao-Tao,Wang, Xiao-Dong,Wu, Lei
p. 1788 - 1792
(2018/04/30)

Alternative Strategies with Iodine: Fast Access to Previously Inaccessible Iodine(III) Compounds
Non-iodinated arenes can be easily and selectively converted into (diacetoxyiodo)arenes in a single step under mild conditions by using iodine triacetates as reagents. The oxidative step is decoupled from the synthesis of hypervalent iodine(III) reagents, which can now be prepared conveniently in a one-pot synthesis for subsequent reactions without prior purification. The chemistry of iodine triacetates was also expanded to heteroatom ligand exchanges to form novel inorganic hypervalent iodine compounds.
Hokamp, Tobias,Mollari, Leonardo,Wilkins, Lewis C.,Melen, Rebecca L.,Wirth, Thomas
p. 8306 - 8309
(2018/06/29)

Cis -Oxoruthenium complexes supported by chiral tetradentate amine (N4) ligands for hydrocarbon oxidations
We report the first examples of ruthenium complexes cis-[(N4)RuIIICl2]+ and cis-[(N4)RuII(OH2)2]2+ supported by chiral tetradentate amine ligands (N4), together with a high-valent cis-dioxo complex cis-[(N4)RuVI(O)2]2+ supported by the chiral N4 ligand mcp (mcp = N,N′-dimethyl-N,N′-bis(pyridin-2-ylmethyl)cyclohexane-1,2-diamine). The X-ray crystal structures of cis-[(mcp)RuIIICl2](ClO4) (1a), cis-[(Me2mcp)RuIIICl2]ClO4 (2a) and cis-[(pdp)RuIIICl2](ClO4) (3a) (Me2mcp = N,N′-dimethyl-N,N′-bis((6-methylpyridin-2-yl)methyl)cyclohexane-1,2-diamine, pdp = 1,1′-bis(pyridin-2-ylmethyl)-2,2′-bipyrrolidine)) show that the ligands coordinate to the ruthenium centre in a cis-α configuration. In aqueous solutions, proton-coupled electron-transfer redox couples were observed for cis-[(mcp)RuIII(O2CCF3)2]ClO4 (1b) and cis-[(pdp)RuIII(O3SCF3)2]CF3SO3 (3c′). Electrochemical analyses showed that the chemically/electrochemically generated cis-[(mcp)RuVI(O)2]2+ and cis-[(pdp)RuVI(O)2]2+ complexes are strong oxidants with E° = 1.11-1.13 V vs. SCE (at pH 1) and strong H-atom abstractors with DO-H = 90.1-90.8 kcal mol-1. The reaction of 1b or its (R,R)-mcp counterpart with excess (NH4)2[CeIV(NO3)6] (CAN) in aqueous medium afforded cis-[(mcp)RuVI(O)2](ClO4)2 (1e) or cis-[((R,R)-mcp)RuVI(O)2](ClO4)2 (1e?), respectively, a strong oxidant with E(RuVI/V) = 0.78 V (vs. Ag/AgNO3) in acetonitrile solution. Complex 1e oxidized various hydrocarbons, including cyclohexane, in acetonitrile at room temperature, affording alcohols and/or ketones in up to 66% yield. Stoichiometric oxidations of alkenes by 1e or 1e? in tBuOH/H2O (5:1 v/v) afforded diols and aldehydes in combined yields of up to 98%, with moderate enantioselectivity obtained for the reaction using 1e?. The cis-[(pdp)RuII(OH2)2]2+ (3c)-catalysed oxidation of saturated C-H bonds, including those of ethane and propane, with CAN as terminal oxidant was also demonstrated.
Tse, Chun-Wai,Liu, Yungen,Wai-Shan Chow, Toby,Ma, Chaoqun,Yip, Wing-Ping,Chang, Xiao-Yong,Low, Kam-Hung,Huang, Jie-Sheng,Che, Chi-Ming
p. 2803 - 2816
(2018/03/21)

Kinetic Resolution of 1,2-Diols via NHC-Catalyzed Site-Selective Esterification
A kinetic resolution of 1,2-diols bearing both a secondary and a primary alcohol motif through an N-heterocyclic carbene-catalyzed oxidative acylation reaction has been developed. A site- and enantioselective esterification reaction is involved for this process. Both the monoacylated diols obtained and the remaining enantioenriched 1,2-diols are versatile building blocks for the preparation of functional molecules with proven biological activities.
Liu, Bin,Yan, Jiekuan,Huang, Ruoyan,Wang, Weihong,Jin, Zhichao,Zanoni, Giuseppe,Zheng, Pengcheng,Yang, Song,Chi, Yonggui Robin
supporting information
p. 3447 - 3450
(2018/06/26)

Carbohydrate/DBU Cocatalyzed Alkene Diboration: Mechanistic Insight Provides Enhanced Catalytic Efficiency and Substrate Scope
A mechanistic investigation of the carbohydrate/DBU cocatalyzed enantioselective diboration of alkenes is presented. These studies provide an understanding of the origin of stereoselectivity and also reveal a strategy for enhancing reactivity and broadening the substrate scope.
Yan, Lu,Meng, Yan,Haeffner, Fredrik,Leon, Robert M.,Crockett, Michael P.,Morken, James P.
supporting information
p. 3663 - 3673
(2018/03/21)

Alkylative kinetic resolution of vicinal diols under phase-transfer conditions: A chiral ammonium borinate catalysis
Herein, we report the first alkylative kinetic resolution of vicinal alcohols realized by cooperative use of a chiral quaternary ammonium salt and an achiral borinic acid. In addition, a catalytic regioselective alkylation of a secondary alcohol in the presence of an unprotected primary one is presented, emphasizing the unique selectivity and potential of this ammonium borinate catalysis.
Pawliczek, Martin,Hashimoto, Takuya,Maruoka, Keiji
p. 1231 - 1235
(2018/02/09)

Norepinephrine alkaloids as antiplasmodial agents: Synthesis of syncarpamide and insight into the structure-activity relationships of its analogues as antiplasmodial agents
Syncarpamide 1, a norepinephrine alkaloid isolated from the leaves of Zanthoxylum syncarpum (Rutaceae) exhibited promising antiplasmodial activities against Plasmodium falciparum with reported IC50 values of 2.04 μM (D6 clone), 3.06 μM (W2 clone) and observed by us 3.90 μM (3D7 clone) and 2.56 μM (K1 clone). In continuation of our work on naturally occurring antimalarial compounds, synthesis of syncarpamide 1 and its enantiomer, (R)-2 using Sharpless asymmetric dihydroxylation as a key step has been accomplished. In order to study structure-activity-relationship (SAR) in detail, a library of 55 compounds (3–57), which are analogues/homologues of syncarpamide 1 were synthesized by varying the substituents on the aromatic ring, by changing the stereocentre at the C-7 and/or by varying the acid groups in the ester and/or amide side chain based on the natural product lead molecule and further assayed in vitro against 3D7 and K1 strains of P. falciparum to evaluate their antiplasmodial activities. In order to study the effect of position of functional groups on antiplasmodial activity profile, a regioisomer (S)-58 of syncarpamide 1 was synthesized however, it turned out to be inactive against both the strains. Two compounds, (S)-41 and its enantiomer, (R)-42 having 3,4,5-trimethoxy cinnamoyl groups as side chains showed better antiplasmodial activity with IC50 values of 3.16, 2.28 μM (3D7) and 1.78, 2.07 μM (K1), respectively than the natural product, syncarpamide 1. Three compounds (S)-13, (S)-17, (S)-21 exhibited antiplasmodial activities with IC50 values of 6.39, 6.82, 6.41 μM against 3D7 strain, 4.27, 7.26, 2.71 μM against K1 strain and with CC50 values of 147.72, 153.0, >200 μM respectively. The in vitro antiplasmodial activity data of synthesized library suggests that the electron density and possibility of resonance in both the ester and amide side chains increases the antiplasmodial activity as compared to the parent natural product 1. The natural product syncarpamide 1 and four analogues/homologues out of the synthesized library of 55, (S)-41, (R)-42, (S)-55 and (S)-57 were assayed in vivo assay against chloroquine-resistant P. yoelii (N-67) strain of Plasmodium. However, none of the five molecules, 1, (S)-41, (R)-42, (S)-55 and (S)-57 exhibited any promising in vivo antimalarial activity against P. yoelii (N-67) strain. Compounds 4, 6, 7 and 11 showed high cytotoxicities with CC50 values of 5.87, 5.08, 6.44 and 14.04 μM, respectively. Compound 6 was found to be the most cytotoxic as compared to the standard drug, podophyllotoxin whereas compounds 4 and 7 showed comparable cytotoxicities to podophyllotoxin.
Aratikatla, Eswar K.,Valkute, Tushar R.,Puri, Sunil K.,Srivastava, Kumkum,Bhattacharya, Asish K.
supporting information
p. 1089 - 1105
(2017/08/03)

One-Pot Enantioselective Synthesis of d-Phenylglycines from Racemic Mandelic Acids, Styrenes, or Biobased l-Phenylalanine via Cascade Biocatalysis
Enantiopure d-phenylglycine and its derivatives are an important group of chiral amino acids with broad applications in thepharmaceutical industry. However, the existing synthetic methods for d-phenylglycine mainly rely on toxic cyanide chemistry and multistep processes. To provide green and safe alternatives, we envisaged cascade biocatalysis for the one-pot synthesis of d-phenylglycine from racemic mandelic acid, styrene, and biobased l-phenylalanine, respectively. Recombinant Escherichia coli (LZ110) was engineered to coexpress four enzymes to catalyze a 3-step reaction in one pot, transforming mandelic acid (210 mM) to give enantiopure d-phenylglycine in 29.5 g L?1 (195 mM) with 93% conversion. Using the same whole-cell catalyst, twelve other d-phenylglycine derivatives were also produced from the corresponding mandelic acid derivatives in high conversion (58–94%) and very high ee (93–99%). E. coli (LZ116) expressing seven enzymes was constructed for the transformation of styrene to enantiopure d-phenylglycine in 80% conversion via a one-pot 6-step cascade biotransformation. Twelve substituted d-phenylglycines were also produced from the corresponding styrene derivatives in high conversion (45–90%) and very high ee (92–99%) via the same cascade reactions. A nine-enzymeexpressing E. coli (LZ143) was engineered to transform biobased l-phenylalanine to enantiopure d-phenylglycine in 83% conversion via a one-pot 8-step transformation. Preparative biotransformations were also demonstrated. The high-yielding synthetic methods use cheap and green reagents (ammonia, glucose, and/or oxygen), and E. coli whole-cell catalysts, thus providing green and useful alternative methods for manufacturing d-phenylglycine. (Figure presented.).
Zhou, Yi,Wu, Shuke,Li, Zhi
p. 4305 - 4316
(2017/11/21)

Homochiral Metal-Organic Frameworks with Tunable Nanoscale Channel Array and Their Enantioseparation Performance against Chiral Diols
Enantioseparation is an integral process in the pharmaceutical industry, considering the ever-increasing demand for chiral medicine products. As a new material, porous metal-organic frameworks (MOFs) have shown their potential application in this field because their structures are easy to adjust and control. Though chiral recognition between racemic substrates and frameworks has made preliminary progress, discussions of their size-matching effects are rare. Herein with the help of channel-tunable homochiral MOFs (HMOFs), diols of different sizes have been separated in good enantiomeric excess (ee%). In addition, the ee% reaches 67.4% for the first time for diols as large as 1,1,2-triphenyl-1,2-ethanediol, which turns out to be the most effective value so far.
Zhuo, Chao,Wen, Yuehong,Hu, Shengmin,Sheng, Tianlu,Fu, Ruibiao,Xue, Zhenzhen,Zhang, Hao,Li, Haoran,Yuan, Jigang,Chen, Xi,Wu, Xintao
supporting information
p. 6275 - 6280
(2017/06/13)

A chiral three teeth PNN ligand and its asymmetric hydrogenation reaction in the application of the
The invention discloses a chiral tridentate PNN ligand and application of the same in asymmetric hydrogenation and similar reactions. The tridentate nitrogen phosphine ligand disclosed in the invention has been the first reported nitrogen phosphine ligand containing chiral oxazoline so far and has been successfully applied to high-efficiency and high-selectivity hydrogenation and similar reactions of ketone and imine salts. Compared with other ligand, the ligand provided by the invention is simpler in synthetic route, higher in yield and environment-friendlier; moreover, the metal complex of the ligand shows better selectivity and a higher turn-over number in asymmetric hydrogenation. An iridium complex of the chiral tridentate PNN ligand has successfully realized asymmetric reduction of beta-ketone ester into beta-alcohol ester (which is a raw material for synthesis of molecular drugs duloxetine and atomoxetine), asymmetric hydrogenation of alpha-hydroxyacetophenone into alpha-hydroxyphenylethyl alcohol and asymmetric hydrogenation of acetophenone into phenylethyl alcohol, which is of important significance to production of the medical industry.
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Paragraph 0089-0090

(2018/03/24)

Alternatives to Phosphinooxazoline (t-BuPHOX) Ligands in the Metal-Catalyzed Hydrogenation of Minimally Functionalized Olefins and Cyclic β-Enamides
This study presents a new series of readily accessible iridium- and rhodium-phosphite/oxazoline catalytic systems that can efficiently hydrogenate, for the first time, both minimally functionalized olefins and functionalized olefins (62 examples in total) in high enantioselectivities (ees up to >99%) and conversions. The phosphite-oxazoline ligands, which are readily available in only two synthetic steps, are derived from previous privileged 4-alkyl-2-[2-(diphenylphosphino)phenyl]-2-oxazoline (PHOX) ligands by replacing the phosphine moiety by a biaryl phosphite group and/or the introduction of a methylene spacer between the oxazoline and the phenyl ring. The modular design of the ligands has given us the opportunity not only to overcome the limitations of the iridium-PHOX catalytic systems in the hydrogenation of minimally functionalized Z-olefins and 1,1-disubstituted olefins, but also to expand their use to unfunctionalized olefins containing other challenging scaffolds (e.g., exocyclic benzofused and triaryl-substituted olefins) and also to olefins with poorly coordinative groups (e.g., α,β-unsaturated lactams, lactones, alkenylboronic esters, etc.) with enantioselectivities typically >95% ee. Moreover, both enantiomers of the hydrogenation product could be obtained by simply changing the configuration of the biaryl phosphite moiety. Remarkably, the new catalytic systems also provided excellent enantioselectivities (up to 99% ee) in the asymmetric hydrogenation of another challenging class of olefins – the functionalized cyclic β-enamides. Again, both enantiomers of the reduced amides could be obtained by changing the metal from Ir to Rh. We also demonstrated that environmentally friendly propylene carbonate can be used with no loss of enantioselectivity. Another advantage of the new ligands over the PHOX ligands is that the best ligands are derived from the affordable (S)-phenylglycinol rather than from the expensive (S)-tert-leucinol. (Figure presented.).
Biosca, Maria,Magre, Marc,Coll, Mercè,Pàmies, Oscar,Diéguez, Montserrat
supporting information
p. 2801 - 2814
(2017/08/23)

Enantioselective Vicinal Diacetoxylation of Alkenes under Chiral Iodine(III) Catalysis
A procedure for the intermolecular enantioselective dioxygenation of alkenes under iodine(III) catalysis has been developed. This protocol employs Selectfluor as the terminal oxidant together with a defined C 2-symmetric aryl iodide as the organocatalyst. This enantioselective reaction proceeds under mild conditions and converts a series of terminal and internal styrenes into the corresponding vicinal diacetoxylation products with up to 96% ee.
W?ste, Thorsten H.,Mu?iz, Kilian
p. 816 - 827
(2016/03/15)

Chiral N-heterocyclic carbene iridium catalyst for the enantioselective hydrosilane reduction of ketones
Enantioselective reduction of ketones with (EtO)2MeSiH catalyzed by an in-situ generated N-heterocyclic carbene (NHC) Ir complex at room temperature has been developed. A series of benzimidazolium salts were synthesized and screened in the asymmetric hydrosilylation reaction. As a result, propiophenone was efficiently reduced by the combined catalytic system of [IrCl(cod)]2 and NHC-Ag complex derived from N-(1-naphthalenylmethyl)-substituted benzimidazolium salt L12, affording the corresponding alcohol in 92% yield and with 92% ee. Moreover, the evaluation of an Ir catalyst precursor showed that cationic [Ir(cod)2]BF4 complex could be used. Furthermore, the introduction of a chiral hydroxyamide side arm into the benzimidazolium salt was critical for the successful design of the NHC ligand.
Manabe, Yoshiki,Shinohara, Kanako,Nakamura, Hanako,Teramoto, Hiro,Sakaguchi, Satoshi
p. 138 - 145
(2016/06/15)

Efficient bioreduction of 2-hydroxyacetophenone to (S)-1-phenyl-1, 2-ethanediol through homologous expression of (S)-carbonyl reductase II in Candida parapsilosis CCTCC M203011
(S)-carbonyl reductase II (SCRII), a short-chain alcohol dehydrogenase from Candida parapsilosis M203011, catalyzes the bioreduction of 2-hydroxyacetophenone (2-HAP) to (S)-1-phenyl-1,2-ethanediol ((S)-PED). When SCRII was expressed in Escherichia coli, the biotransformation efficiency of (S)-PED was low. To improve its biocatalytic efficiency, the homologous expression of SCRII in C. parapsilosis M203011 was attempted. The scrII gene was cloned into an expression vector pCP carrying MAL2 as its promoter and SAT1 as its selection marker. Data obtained in this study showed that SCRII was successfully expressed in recombinant strain C. parapsilosis/pCP-scrII. The reductive activity toward 2-HAP exhibited about 2-fold and 6-fold increase in the cell-free extracts of C. parapsilosis/pCP-scrII than those of the wild-type and E. coli/pET28-SCRII. Under the optimal bioreaction conditions (pH 5.5, 35?°C), the optical purity and yield of (S)-PED were both over 99.9% produced by C. parapsilosis/pCP-scrII. Additionally, 500-mL preparative scale bioreduction with efficient whole-cell process was performed, and the optical purity was over 99.9% with an isolated yield of about 70%. Our work not only demonstrated the high catalytic efficiency given by the homologous expression of SCRII in C. parapsilosis, but also provides an economical method for the preparation of optically pure chiral alcohols with whole-cell process.
Li, Yaohui,Zhang, Rongzhen,Xu, Yan,Xiao, Rong,Wang, Lei,Zhou, Xiaotian,Liang, Hongbo,Jiang, Jiawei
p. 1175 - 1182
(2016/08/09)

ANTI-MALARIAL COMPOUNDS AND PROCESS FOR PREPARATION THEREOF
The present invention discloses anti-malarial compound of formula (I) Formula (I) wherein, X is selected from O or NH; R1, R2, R3, R4 and R5 is selected from H or OMe or CH3, -CH2-O-CH2- or -CH=CH-CH=CH-; Y is selected from O or NH and R6, R7 is selected from the following compounds: or pharmaceutically acceptable salts thereof, process for preparation and a pharmaceutical composition containing the same.
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Page/Page column 10; 11

(2016/05/24)

Production Of Enantiopure alpha-Hydroxy Carboxylic Acids From Alkenes By Cascade Biocatalysis
The invention provides compositions comprising an alkene epoxidase and a selective epoxide hydrolase, such as a recombinant microorganism comprising a first heterologous nucleic acid encoding an alkene epoxidase and a second heterologous nucleic acid encoding a selective epoxide hydrolase. Exemplary alkene epoxidases include StyAB, while exemplary selective epoxide hydrolases include epoxide hydrolases from Sphingomonas, Solanum tuberosum, or Aspergillus. The invention also provides non-toxic methods of making enantiomerically pure vicinal diols or enantiomerically pure alpha-hydroxy carboxylic acids using these compositions and microorganisms.
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Paragraph 0065-0067

(2016/05/02)

Structurally Defined Molecular Hypervalent Iodine Catalysts for Intermolecular Enantioselective Reactions
Molecular structures of the most prominent chiral non-racemic hypervalent iodine(III) reagents to date have been elucidated for the first time. The formation of a chirally induced supramolecular scaffold based on a selective hydrogen-bonding arrangement provides an explanation for the consistently high asymmetric induction with these reagents. As an exploratory example, their scope as chiral catalysts was extended to the enantioselective dioxygenation of alkenes. A series of terminal styrenes are converted into the corresponding vicinal diacetoxylation products under mild conditions and provide the proof of principle for a truly intermolecular asymmetric alkene oxidation under iodine(I/III) catalysis.
Haubenreisser, Stefan,W?ste, Thorsten H.,Martnez, Claudio,Ishihara, Kazuaki,Muiz, Kilian
supporting information
p. 413 - 417
(2016/01/25)

Carbohydrate-Catalyzed Enantioselective Alkene Diboration: Enhanced Reactivity of 1,2-Bonded Diboron Complexes
Catalytic enantioselective diboration of alkenes is accomplished with readily available carbohydrate-derived catalysts. Mechanistic experiments suggest the intermediacy of 1,2-bonded diboronates.
Fang, Lichao,Yan, Lu,Haeffner, Fredrik,Morken, James P.
supporting information
p. 2508 - 2511
(2016/03/12)

Highly Enantioselective Iron-Catalyzed cis-Dihydroxylation of Alkenes with Hydrogen Peroxide Oxidant via an FeIII-OOH Reactive Intermediate
The development of environmentally benign catalysts for highly enantioselective asymmetric cis-dihydroxylation (AD) of alkenes with broad substrate scope remains a challenge. By employing [FeII(L)(OTf)2] (L=N,N′-dimethyl-N,N′-bis(2-methyl-8-quinolyl)-cyclohexane-1,2-diamine) as a catalyst, cis-diols in up to 99.8 % ee with 85 % isolated yield have been achieved in AD of alkenes with H2O2as an oxidant and alkenes in a limiting amount. This “[FeII(L)(OTf)2]+H2O2” method is applicable to both (E)-alkenes and terminal alkenes (24 examples >80 % ee, up to 1 g scale). Mechanistic studies, including18O-labeling, UV/Vis, EPR, ESI-MS analyses, and DFT calculations lend evidence for the involvement of chiral FeIII-OOH active species in enantioselective formation of the two C?O bonds.
Zang, Chao,Liu, Yungen,Xu, Zhen-Jiang,Tse, Chun-Wai,Guan, Xiangguo,Wei, Jinhu,Huang, Jie-Sheng,Che, Chi-Ming
supporting information
p. 10253 - 10257
(2016/08/24)

HPLC enantioseparation on a homochiral MOF-silica composite as a novel chiral stationary phase
The last frontier in the development of chiral stationary phases for chromatographic enantioseparation involves homochiral metal-organic frameworks (MOFs). Using enantiopure (R)-2,2′-dihydroxy-1,1′-binaphthalene-6,6′-dicarboxylic acid as a starting material, we prepared three homochiral MOFs that were further used as chiral stationary phases for high-performance liquid chromatography to separate the enantiomers of various kinds of racemic sulfoxides, sec-alcohols, β-lactams, benzoins, flavanones and epoxides. The experimental results showed excellent performances for enantioseparation, and highlighted that enantioseparation on homochiral MOF columns is practical.
Tanaka, Koichi,Muraoka, Toshihide,Otubo, Yasuhiro,Takahashi, Hiroki,Ohnishi, Atsushi
p. 21293 - 21301
(2016/03/08)

Efficient HPLC enantiomer separation using a pillared homochiral metal-organic framework as a novel chiral stationary phase
HPLC enantioseparation of racemates using novel pillared homochiral metal-organic framework-silica composite as chiral stationary phase has been successfully demonstrated.
Tanaka, Koichi,Hotta, Naoki,Nagase, Shohei,Yoza, Kenji
supporting information
p. 4891 - 4894
(2016/07/06)

Highly selective anti-Prelog synthesis of optically active aryl alcohols by recombinant Escherichia coli expressing stereospecific alcohol dehydrogenase
Biocatalytic asymmetric synthesis has been widely used for preparation of optically active chiral alcohols as the important intermediates and precursors of active pharmaceutical ingredients. However, the available whole-cell system involving anti-Prelog specific alcohol dehydrogenase is yet limited. A recombinant Escherichia coli system expressing anti-Prelog stereospecific alcohol dehydrogenase from Candida parapsilosis was established as a whole-cell system for catalyzing asymmetric reduction of aryl ketones to anti-Prelog configured alcohols. Using 2-hydroxyacetophenone as the substrate, reaction factors including pH, cell status, and substrate concentration had obvious impacts on the outcome of whole-cell biocatalysis, and xylose was found to be an available auxiliary substrate for intracellular cofactor regeneration, by which (S)-1-phenyl-1,2-ethanediol was achieved with an optical purity of 97%e.e. and yield of 89% under the substrate concentration of 5?g/L. Additionally, the feasibility of the recombinant cells toward different aryl ketones was investigated, and most of the corresponding chiral alcohol products were obtained with an optical purity over 95%e.e. Therefore, the whole-cell system involving recombinant stereospecific alcohol dehydrogenase was constructed as an efficient biocatalyst for highly enantioselective anti-Prelog synthesis of optically active aryl alcohols and would be promising in the pharmaceutical industry.
Li, Ming,Nie, Yao,Mu, Xiao Qing,Zhang, Rongzhen,Xu, Yan
p. 429 - 433
(2016/08/11)

Chiral tridentate nitrogen-phosphine-oxygen ligands and application of related ligands in asymmetric catalytic reactions
The invention relates to PNHO tridentate ligands and application of related ligands in asymmetric hydrogenation and similar reactions. The novel tridentate nitrogen-phosphine-oxygen ligands are first tridentate nitrogen-phosphine-oxygen ligands containing ferrocenyl planar chiral phosphine, and are successfully applied to high-efficiency high-selectivity asymmetric hydrogenation and other similar reactions of simple aromatic ketone, alpha-hydroxyketone and beta-ketone ester. Compared with other dominant tridentate ligands, the ligands provided by the invention have the advantages of simple synthesis route and low cost, can easily implement large-scale synthesis, are stable in air, and have high activity and high selectivity in asymmetric hydrogenation reactions of carbon-oxygen double bonds.
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Paragraph 0112; 0113; 0114

(2016/10/20)

Cascade Biocatalysis for Sustainable Asymmetric Synthesis: From Biobased l-Phenylalanine to High-Value Chiral Chemicals
Sustainable synthesis of useful and valuable chiral fine chemicals from renewable feedstocks is highly desirable but remains challenging. Reported herein is a designed and engineered set of unique non-natural biocatalytic cascades to achieve the asymmetric synthesis of chiral epoxide, diols, hydroxy acid, and amino acid in high yield and with excellent ee values from the easily available biobased l-phenylalanine. Each of the cascades was efficiently performed in one pot by using the cells of a single recombinant strain over-expressing 4–10 different enzymes. The cascade biocatalysis approach is promising for upgrading biobased bulk chemicals to high-value chiral chemicals. In addition, combining the non-natural enzyme cascades with the natural metabolic pathway of the host strain enabled the fermentative production of the chiral fine chemicals from glucose.
Zhou, Yi,Wu, Shuke,Li, Zhi
supporting information
p. 11647 - 11650
(2016/11/17)