33758-16-6Relevant academic research and scientific papers
Optimized Reaction Conditions Enable the Hydration of Non-natural Substrates by the Oleate Hydratase from Elizabethkingia meningoseptica
Demming, Rebecca M.,Otte, Konrad B.,Nestl, Bettina M.,Hauer, Bernhard
, p. 758 - 766 (2017)
The oleate hydratase from Elizabethkingia meningoseptica (Em-OAH) catalyzes the hydration of oleic acid (C18) to (R)-10-hydroxystearic acid. In previous work, low activity of Em-OAH towards chemically synthesized (Z)-undec-9-enoic acid (C11) was observed. Product formation in the hydration of the truncated C11 substrate was improved by optimizing the reaction conditions by applying statistical experiment design. Optimized reaction conditions resulted in a 2.8-fold increase in product formation in just one quarter of the time (64 % conversion in 28 h). The applicability has been assessed in the upscaling of the conversion of (Z)-undec-9-enoic acid to (S)-10-hydroxyundecanoic acid (132 mg product, >95 % purity). Reaction conditions developed for the hydration of C11 facilitated the first hydration of non-natural alkenes. By using a fatty acid dummy substrate, 1-decene was successfully hydrated to (S)-2-decanol with excellent stereoselectivity and 50 % conversion after four days of incubation.
Asymmetric Enzymatic Hydration of Unactivated, Aliphatic Alkenes
Demming, Rebecca M.,Hammer, Stephan C.,Nestl, Bettina M.,Gergel, Sebastian,Fademrecht, Silvia,Pleiss, Jürgen,Hauer, Bernhard
supporting information, p. 173 - 177 (2018/12/11)
The direct enantioselective addition of water to unactivated alkenes could simplify the synthesis of chiral alcohols and solve a long-standing challenge in catalysis. Here we report that an engineered fatty acid hydratase can catalyze the asymmetric hydration of various terminal and internal alkenes. In the presence of a carboxylic acid decoy molecule for activation of the oleate hydratase from E. meningoseptica, asymmetric hydration of unactivated alkenes was achieved with up to 93 % conversion, excellent selectivity (>99 % ee, >95 % regioselectivity), and on a preparative scale.
Identification of a Robust Carbonyl Reductase for Diastereoselectively Building syn-3,5-Dihydroxy Hexanoate: A Bulky Side Chain of Atorvastatin
Gong, Xu-Min,Zheng, Gao-Wei,Liu, You-Yan,Xu, Jian-He
supporting information, p. 1349 - 1354 (2017/09/23)
t-Butyl-6-cyano-(3R,5R)-dihydroxyhexanoate is an advanced chiral precursor for the synthesis of the side chain pharmacophore of cholesterol-lowering drug atorvastatin. Herein, a robust carbonyl reductase (LbCR) was newly identified from Lactobacillus brevis, which displays high activity and excellent diastereoselectivity toward bulky t-butyl 6-cyano-(5R)-hydroxy-3-oxo-hexanoate (7). The engineered Escherichia coli cells harboring LbCR and glucose dehydrogenase (for cofactor regeneration) were employed as biocatalysts for the asymmetric reduction of substrate 7. As a result, as much as 300 g L-1 of water-insoluble substrate was completely converted to the corresponding chiral diol with >99.5% de in a space-time yield of 351 g L-1 d-1, indicating a great potential of LbCR for practical synthesis of the very bulky and bi-chiral 3,5-dihydroxy carboxylate side chain of best-selling statin drugs.
Chiral Surfactant-Type Catalyst: Enantioselective Reduction of Long-Chain Aliphatic Ketoesters in Water
Lin, Zechao,Li, Jiahong,Huang, Qingfei,Huang, Qiuya,Wang, Qiwei,Tang, Lei,Gong, Deying,Yang, Jun,Zhu, Jin,Deng, Jingen
, p. 4419 - 4429 (2015/05/13)
A series of amphiphilic ligands were designed and synthesized. The rhodium complexes with the ligands were applied to the asymmetric transfer hydrogenation of broad range of long-chained aliphatic ketoesters in neat water. Quantitative conversion and excellent enantioselectivity (up to 99% ee) was observed for α-, β-, γ-, δ- and ε-ketoesters as well as for α- and β-acyloxyketone using chiral surfactant-type catalyst 2. The CH/π interaction and the strong hydrophobic interaction of long aliphatic chains between the catalyst and the substrate in the metallomicelle core played a key role in the catalytic transition state. Synergistic effects between the metal-catalyzed site and the hydrophobic microenvironment of the core in the micelle contributed to high stereoselectivity. (Chemical Equation Presented).
A novel P450-based biocatalyst for the selective production of chiral 2-alkanols
Von Bühler, Clemens J.,Urlacher, Vlada B.
supporting information, p. 4089 - 4091 (2014/04/03)
A P450 monooxygenase from Nocardia farcinica (CYP154A8) catalyses the stereo- and regioselective hydroxylation of n-alkanes, still a challenging task in chemical catalysis. In a biphasic reaction system, the regioselectivity for the C2-position of C7-C9 alkanes was over 90%. The enzyme showed strict S-selectivity for all tested substrates, with enantiomeric excess (ee) of up to 91%. This journal is the Partner Organisations 2014.
Catalytic enantioselective addition of alkyl grignard reagents to aliphatic aldehydes
Fernandez-Mateos, Emilio,Macia, Beatriz,Yus, Miguel
supporting information, p. 1249 - 1254 (2013/06/27)
Herein, we report an efficient catalytic system for the enantioselective addition of alkyl Grignard reagents to a broad range of aliphatic aldehydes with good yields and enantioselectivities. Remarkably, the challenging methylmagnesium bromide (MeMgBr) can also be added to a variety of aliphatic aldehydes, providing versatile chiral methyl carbinol units with unprecedented yields and enantioselectivities in a simple one-pot procedure under mild conditions. Copyright
Continuous biphasic enzymatic reduction of aliphatic ketones
Leuchs, Susanne,Nonnen, Thomas,Dechambre, Dominique,Na'Amnieh, Shukralla,Greiner, Lasse
, p. 52 - 59 (2013/08/24)
Biphasic reactions offer an attractive alternative for the utilisation of enzymes for conversion of hardly water soluble substrates. Especially, the alcohol dehydrogenase from Lactobacillus brevis was successfully used for the reductive synthesis of enantiopure secondary aliphatic alcohols. With the enzymatic catalyst and the cofactor effectively retained in the reactive aqueous phase, the continuous operation was demonstrated by continuous addition and withdrawal of the non-reactive phase. The four tested substrates 2-heptanone, 2-octanone, 2-nonanone, and 2-decanone showed that the space time yield and turnover numbers (TON) of the enzyme decrease as the availability of the substrate decreases with increasing partition coefficients. Nevertheless, a TONLbADH of up to 478 × 103 could be achieved. Remarkably, the cofactor utilisation turned out to be very high and a TON NADP+ of more than 20 × 103 was easily achievable for both 2-heptanone and 2-octanone by substrate coupled cofactor regeneration with excess of 2-propanol.
The substrate spectrum of the inverting sec-alkylsulfatase Pisa1
Schober, Markus,Knaus, Tanja,Toesch, Michael,MacHeroux, Peter,Wagner, Ulrike,Faber, Kurt
, p. 1737 - 1742 (2012/07/31)
The substrate spectrum of the inverting alkylsulfatase Pisa1 was investigated using a range of sec-alkyl sulfate esters bearing aromatic, olefinic and acetylenic moieties. Perfect enantioselectivities were obtained for substrates bearing groups of different size adjacent to the sulfate ester moiety. Insufficient selectivities could be doubled by using dimethyl sulfoxide (DMSO) as co-solvent. Hydrolytically unstable benzylic sulfate esters could be sufficiently stabilised by introduction of electron-withdrawing substituents. Overall, Pisa1 appears to be a very useful inverting alkylsulfatase for the deracemisation of rac-sec-alcohols via enzymatic hydrolysis of their corresponding sulfate esters, which furnishes homochiral products possessing the 'anti-Kazlauskas' configuration. Copyright
Chiral surfactant-type catalyst for asymmetric reduction of aliphatic ketones in water
Li, Jiahong,Tang, Yuanfu,Wang, Qiwei,Li, Xuefeng,Cun, Linfeng,Zhang, Xiaomei,Zhu, Jin,Li, Liangchun,Deng, Jingen
supporting information, p. 18522 - 18525 (2013/01/15)
A novel chiral surfactant-type catalyst is developed. Micelles formed in water by association of the catalysts themselves, and this was confirmed by TEM analyses. Asymmetric transfer hydrogenation of aliphatic ketones catalyzed by the chiral metallomicellar catalyst gave good to excellent conversions and remarkable stereoselectivities (up to 95% ee). Synergistic effects between the metal-catalyzed center and the hydrophobic microenvironment of the core in the metallomicelle led to high enantioselectivities.
Stereospecific inversion of secondary tosylates to yield chiral methyl-branched building blocks, applied to the asymmetric synthesis of leafminer sex pheromones
Taguri, Tomonori,Yamakawa, Rei,Fujii, Toru,Muraki, Yuta,Ando, Tetsu
experimental part, p. 852 - 858 (2012/09/22)
All four of the possible stereoisomers of 5,9-dimethylheptadecane, the major sex pheromone component secreted by female moths of the mountain-ash bentwing (Leucoptera scitella), were synthesized by the coupling of two chiral blocks with a methyl branch at the 2- or 3-position. The blocks were prepared by applying the stereospecific inversion of secondary tosylates, which were derived from (R)- and (S)-propylene oxide, and their enantiopurities were confirmed by chiral HPLC analysis.
