152142-03-5Relevant academic research and scientific papers
Engineering chiral polyoxometalate hybrid metal-organic frameworks for asymmetric dihydroxylation of olefins
Han, Qiuxia,He, Cheng,Zhao, Min,Qi, Bo,Niu, Jingyang,Duan, Chunying
, p. 10186 - 10189 (2013)
Chiral metal-organic frameworks (MOFs) with porous and tunable natures have made them feasible for performing a variety of chemical reactions as heterogeneous asymmetric catalysts. By incorporating the oxidation catalyst [BW12O40]5- and the chiral group, l- or d-pyrrolidin-2-ylimidazole (PYI), into one single framework, the two enantiomorphs Ni-PYI1 and Ni-PYI2 were obtained via self-assembly, respectively. The channels of Ni-PYIs were enlarged through a guest exchange reaction to remove the cationic chiral templates and were well modulated with hydrophilic/hydrophobic properties to allow molecules of both H 2O2 and olefin ingress and egress. The coexistence of both the chiral directors and the oxidants within a confined space provided a special environment for the formation of reaction intermediates in a stereoselective fashion with high selectivity. The resulting MOF acted as an amphipathic catalyst to prompt the asymmetric dihydroxylation of aryl olefins with excellent stereoselectivity.
New mono-quarternized bis-Cinchona alkaloid ligands for asymmetric dihydroxylation of olefins in aqueous medium: Unprecedented high enantioselectivity and recyclability
Choi, Doo Seung,Han, Sang Seop,Kwueon, Eun Kyung,Choi, Han Young,Hwang, Soon Ho,Park, Yil Sung,Song, Choong Eui
, p. 2560 - 2564 (2006)
New mono-quaternized allyl bromide salts of bis-Cinchona alkaloid ligands, [(QD)2PHAL-Allyl]Br and [(QN)2PHAL-Allyl]Br, have been synthesized which can be converted into their highly water-soluble multihydroxylated derivatives under asymmetric dihydroxylation (AD) conditions and, thus, easily recovered by a simple extraction method after reaction and reused. These mono-quaternized ligands exhibited superior catalytic efficiency to their neutral counterparts such as (DHQD)2PHAL and (DHQ) 2PHAL for the AD reactions of mono- and disubstituted styrenes under Upjohn conditions. Merely 0.1 mol% of osmium was enough to complete the reactions of mono- and disubstituted styrenes and, moreover, these ligands showed the highest enantioselectivities (e.g., for styrene, 97% ee with [(QD)2PHAL-Allyl]Br) among those ever achieved under Upjohn conditions. Wiley-VCH Verlag GmbH & Co. KGaA.
Method for synthesizing chiral 1,2-diol compound
-
Paragraph 0027; 0045-0048, (2021/07/21)
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).
Reprogramming Epoxide Hydrolase to Improve Enantioconvergence in Hydrolysis of Styrene Oxide Scaffolds
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)
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.).
Highly regio- and enantio-selective hydrolysis of two racemic epoxides by GmEH3, a novel epoxide hydrolase from Glycine max
Zhang, Chen,Li, Chuang,Zhu, Xiu-xiu,Liu, You-yi,Zhao, Jun,Wu, Min-chen
, p. 2795 - 2803 (2020/09/01)
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.
Manipulating regioselectivity of an epoxide hydrolase for single enzymatic synthesis of (: R)-1,2-diols from racemic epoxides
Hu, Die,Zong, Xun-Cheng,Xue, Feng,Li, Chuang,Hu, Bo-Chun,Wu, Min-Chen
supporting information, p. 2799 - 2802 (2020/03/13)
Both the activity and regioselectivity of Phaseolus vulgaris epoxide hydrolase were remarkably improved via reshaping two substrate tunnels based on rational design. The elegant one-step enantioconvergent hydrolysis of seven rac-epoxides was achieved by single mutants, allowing green and efficient access to valuable (R)-1,2 diols with high eep (90.1-98.3%) and yields.
Exploiting Designed Oxidase-Peroxygenase Mutual Benefit System for Asymmetric Cascade Reactions
Yu, Da,Wang, Jian-Bo,Reetz, Manfred T.
, (2019/04/17)
A unique P450 monooxygenase-peroxygenase mutual benefit system was designed as the core element in the construction of a biocatalytic cascade reaction sequence leading from 3-phenyl propionic acid to (R)-phenyl glycol. In this system, P450 monooxygenase (P450-BM3) and P450 peroxygenase (OleTJE) not only function as catalysts for the crucial initial reactions, they also ensure an internal in situ H2O2 recycle mechanism that avoids its accumulation and thus prevents possible toxic effects. By directed evolution of P450-BM3 as the catalyst in the enantioselective epoxidation of the styrene-intermediate, formed from 3-phenyl propionic acid, and the epoxide hydrolase ANEH for final hydrolytic ring opening, (R)-phenyl glycol and 9 derivatives thereof were synthesized from the respective carboxylic acids in one-pot processes with high enantioselectivity.
Exploiting Designed Oxidase-Peroxygenase Mutual Benefit System for Asymmetric Cascade Reactions
Yu, Da,Wang, Jian-Bo,Reetz, Manfred T.
, p. 5655 - 5658 (2019/04/17)
A unique P450 monooxygenase-peroxygenase mutual benefit system was designed as the core element in the construction of a biocatalytic cascade reaction sequence leading from 3-phenyl propionic acid to (R)-phenyl glycol. In this system, P450 monooxygenase (P450-BM3) and P450 peroxygenase (OleTJE) not only function as catalysts for the crucial initial reactions, they also ensure an internal in situ H2O2 recycle mechanism that avoids its accumulation and thus prevents possible toxic effects. By directed evolution of P450-BM3 as the catalyst in the enantioselective epoxidation of the styrene-intermediate, formed from 3-phenyl propionic acid, and the epoxide hydrolase ANEH for final hydrolytic ring opening, (R)-phenyl glycol and 9 derivatives thereof were synthesized from the respective carboxylic acids in one-pot processes with high enantioselectivity.
Syn-dihydroxylation of alkenes using a sterically demanding cyclic diacyl peroxide
Pilevar, Afsaneh,Hosseini, Abolfazl,Becker, Jonathan,Schreiner, Peter R.
, p. 12377 - 12386 (2019/10/11)
The syn-dihydroxylation of alkenes is a highly valuable reaction in organic synthesis. Cyclic acyl peroxides (CAPs) have emerged recently as promising candidates to replace the commonly employed toxic metals for this purpose. Here, we demonstrate that the structurally demanding cyclic peroxide spiro[bicyclo[2.2.1]heptane-2,4′-[1,2]dioxolane]-3′,5′-dione (P4) can be effectively used for the syn-dihydroxylation of alkenes. Reagent P4 also shows an improved selectivity for dihydroxylation of alkenes bearing β-hydrogens as compared to other CAPs, where both diol and allyl alcohol products compete with each other. Furthermore, the use of enantiopure P4 (labeled P4′) demonstrates the potential of P4′ for a metal-free asymmetric syn-dihydroxylation of alkenes.
Cis -Oxoruthenium complexes supported by chiral tetradentate amine (N4) ligands for hydrocarbon oxidations
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)
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.
