100760-04-1Relevant articles and documents
C1-Symmetric PNP Ligands for Manganese-Catalyzed Enantioselective Hydrogenation of Ketones: Reaction Scope and Enantioinduction Model
Zeng, Liyao,Yang, Huaxin,Zhao, Menglong,Wen, Jialin,Tucker, James H. R.,Zhang, Xumu
, p. 13794 - 13799 (2020)
A family of ferrocene-based chiral PNP ligands is reported. These tridentate ligands were successfully applied in Mn-catalyzed asymmetric hydrogenation of ketones, giving high enantioselectivities (92%～99% ee for aryl alkyl ketones) as well as high efficiencies (TON up to 2000). In addition, dialkyl ketones could also be hydrogenated smoothly. Manganese intermediates that might be involved in the catalytic cycle were analyzed. DFT calculation was carried out to help understand the chiral induction model. The Mn/PNP catalyst could discriminate two groups with different steric properties by deformation of the phosphine moiety in the flexible 5-membered ring.
Practical and efficient procedure for the in situ preparation of B-alkoxyoxazaborolidines. Enantioselective reduction of prochiral ketones
Ponzo, Viviana L.,Kaufman, Teodoro S.
, p. 495 - 496 (2000)
A new method for the in situ elaboration of B-alkoxyoxazaborolidines is presented. Their use in the enantioselective reduction of prochiral aromatic ketones provides excellent chemical and optical yields of chiral alcohols.
NH/π attraction: A Role in asymmetric hydrogenation of aromatic ketones with binap/1,2-diamine-ruthenium(II) complexes
Sandoval, Christian A.,Shi, Qixun,Liu, Shasha,Noyori, Ryoji
, p. 1221 - 1224 (2009)
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Imidazolium ion tethered TsDPENs as efficient water-soluble ligands for rhodium catalyzed asymmetric transfer hydrogenation of aromatic ketones
Kang, Guowei,Lin, Silong,Shiwakoti, Atul,Ni, Bukuo
, p. 111 - 114 (2014)
An imidazolium ion tethered TsDPEN has been synthesized readily and used as a water-soluble ligand for [Cp*RhCl2]2 catalyzed asymmetric transfer hydrogenation (ATH) of aromatic ketones in water. This process provided the secondary alcohols in moderate to excellent conversions (up to 100%) with high enantioselectivities (up to 98% ee) under mild reaction conditions without adding any surfactants. The catalytic system is highly effective with the substrate to catalyst (S/C) ratio of 500 and low hydride donor loading of 1.5 equiv. of HCO2Na. The procedure presented is simple and makes this method suitable for practical use.
New air-stable iron catalyst for efficient dynamic kinetic resolution of secondary benzylic and aliphatic alcohols
Yang, Qiong,Zhang, Na,Liu, Mingke,Zhou, Shaolin
, p. 2487 - 2489 (2017)
We herein report a catalyst system for the dynamic kinetic resolution of secondary alcohols by combining the enzymatic resolution with an iron-catalyzed racemization. A new air-stable tricarbonyl (cyclopentadienone)iron complex is identified as the active racemization catalyst for this transformation without any additive. Various substrates including benzylic, heteroaromatic, aliphatic alcohols can be used and afford the corresponding esters in good yields and with excellent enantioselectivities.
Catalytic Asymmetric Addition of Organolithium Reagents to Aldehydes
Veguillas, Marcos,Solà, Ricard,Shaw, Luke,Maciá, Beatriz
, p. 1788 - 1794 (2016)
Herein we report an efficient catalytic system for the titanium-promoted enantioselective addition of organolithium reagents to aldehydes, based on chiral Ar-BINMOL ligands. Unprecedented yields and enantioselectivities are achieved in the alkylation reactions of aliphatic aldehydes. Remarkably, methyllithium can be added to a wide variety of aromatic and aliphatic aldehydes, providing versatile chiral methyl carbinol units in a simple one-pot procedure under mild conditions and in very short reaction times.
Novel (+)-3-carene derivatives and their application in asymmetric synthesis
Roszkowski, Piotr,Malecki, Pawel,Maurin, Jan K.,Czarnocki, Zbigniew
, p. 569 - 574 (2015)
A simple synthetic procedure for the preparation of mono-N-tosylated-1,2-diamines derived from (+)-3-carene is described. (+)-3-Carene is transformed into the corresponding N-tosylaziridine derivative using chloramine-T trihydrate. Subsequent ring opening with sodium azide followed by reduction of the azide function gives the optically pure mono-N-tosylated-1,2-diamine. This ligand is effective in asymmetric transfer hydrogenations of aromatic ketones. It can also be transformed into other chiral ligands by alkylation of the amino group for application in the addition of diethylzinc to benzaldehydes.
Electronic effects of para-substitution on acetophenones in the reaction of rat liver 3α-hydroxysteroid dehydrogenase
Uwai, Koji,Konno, Noboru,Yasuta, Yuka,Takeshita, Mitsuhiro
, p. 1084 - 1089 (2008)
Stereoselective reductive metabolism of various p-substituted acetophenone derivatives was studied using isolated rat liver 3α-hydroxysteroid dehydrogenase (3α-HSD). Kinetic experiments were performed and analyzed by measuring the products by HPLC using a
New silica monolith bonded chiral (R)-γ butyrolactone for enantioselective micro high-performance liquid chromatography
Ghanem, Ashraf,Ikegami, Tohru,Tanaka, Nobuo
, p. 887 - 890 (2011)
A single low-molecular mass chiral selector namely (R)-acryloyloxy-β- β-dimethyl-γ-butyrolactone has been bonded to a modified silica-based monolith to form a new brush-type chiral stationary phase for micro-high performance liquid chromatography (HPLC) separation.
A simple protocol for the one pot synthesis of chiral secondary benzylic alcohols by catalytic enantioselective reduction of aromatic ketones
Ponzo, Viviana L.,Kaufman, Teodoro S.
, p. 1128 - 1130 (2002)
A simple and efficient protocol for the one-pot catalytic enantioselective reduction of prochiral aromatic ketones mediated by in situ prepared catalysis derived from (S)-(-)-diphenyl-pyrrolidin-2-yl-methanol, is reported.
Synthesis, characterization, and organocatalytic application of chiral ionic liquids derived from (S,R)-noscapine
Kaur, Nirmaljeet,Chopra, Harish Kumar
, p. 26 - 31 (2018)
(S,R)-Noscapine, a phthalideisoquinoline alkaloid has been used as precursor for the synthesis of chiral ionic liquids (CILs). Noscapine based CILs have been synthesized from reaction between (S,R)-noscapine and methyl iodide in acetonitrile at room temperature. The synthesized CILs have been characterized by 1H NMR, 13C NMR, EI-MS, and polarimetry techniques. These CILs have been used as organocatalysts in the enantioselective reduction of prochiral ketones to produce optically active secondary alcohols. The optically active secondary alcohols have been obtained with excellent yields and low to moderate enantiomeric excess (ee); also the complete enantiomeric excess (100% ee) has been achieved in some cases.
A Simple Biosystem for the High-Yielding Cascade Conversion of Racemic Alcohols to Enantiopure Amines
Li, Zhi,Tian, Kaiyuan
, p. 21745 - 21751 (2020)
The amination of racemic alcohols to produce enantiopure amines is an important green chemistry reaction for pharmaceutical manufacturing, requiring simple and efficient solutions. Herein, we report the development of a cascade biotransformation to aminate racemic alcohols. This cascade utilizes an ambidextrous alcohol dehydrogenase (ADH) to oxidize a racemic alcohol, an enantioselective transaminase (TA) to convert the ketone intermediate to chiral amine, and isopropylamine to recycle PMP and NAD+ cofactors via the reversed cascade reactions. The concept was proven by using an ambidextrous CpSADH-W286A engineered from (S)-enantioselective CpSADH as the first example of evolving ambidextrous ADHs, an enantioselective BmTA, and isopropylamine. A biosystem containing isopropylamine and E. coli (CpSADH-W286A/BmTA) expressing the two enzymes was developed for the amination of racemic alcohols to produce eight useful and high-value (S)-amines in 72–99 % yield and 98–99 % ee, providing with a simple and practical solution to this type of reaction.
Control of enantioselectivity in the enzymatic reduction of halogenated acetophenone analogs by substituent positions and sizes
Koesoema, Afifa Ayu,Standley, Daron M.,Ohshima, Shusuke,Tamura, Mayumi,Matsuda, Tomoko
, (2020)
We utilized acetophenone reductase from Geotrichum candidum NBRC 4597 (GcAPRD), wild type and Trp288Ala mutant, to reduce halogenated acetophenone analogs to their corresponding (S)- and (R)-alcohols beneficial as pharmaceutical intermediates. Reduction by wild type resulted in excellent (S)-enantioselectivity for all of the substrates tested. Meanwhile, reduction by Trp288Ala resulted in high (R)-enantioselectivity for the reduction of 4′ substituted acetophenone and 2′-trifluoromethylacetophenone. In addition to that, we were able to control the enantioselectivity of Trp288Ala by the positions and sizes of the halogen substituents.
Enantioselective acylation of alcohols catalyzed by lipase QL from Alcaligenes sp.: A predictive active site model for lipase QL to identify the faster reacting enantiomer of an alcohol in this acylation
Naemura,Murata,Tanaka,Yano,Hirose,Tobe
, p. 1581 - 1584 (1996)
Lipase QL-catalyzed acylation of secondary alcohols using isopropenyl acetate as the acylating agent in diisopropyl ether gave preferentially the corresponding acetate with an R configuration. On the basis of the results, a predictive active site model for lipase QL is proposed for identifying which enantiomer of a secondary alcohol reacts faster in this reaction.
Green synthesis of chiral aromatic alcohols with Lactobacillus kefiri P2 as a novel biocatalyst
Bayda?, Yasemin,Dertli, Enes,?ahin, Engin
, p. 1035 - 1045 (2020)
Biocatalytic reduction is a very important field of research in synthetic organic chemistry. Herein, three different Lactic Acid Bacteria (LAB) strains were evaluated for their bioreduction potential using acetophenone as a model substrate. Among these strains, Lactobacillus kefiri P2 strain was determined as the best asymmetric reduction biocatalyst. Reaction optimization parameters such as reaction time, temperature, agitation speed and pH were systematically optimized using Lactobacillus kefiri P2 strain and model substrate acetophenone. Under these optimized reaction conditions, secondary chiral alcohols were obtained by bioreduction of various prochiral ketones with results up to 99% enantiomeric excess. In addition, the steric and electronic effects of substituents on enantioselectivity and conversion were evaluated. It has been shown that Lactobacillus kefiri P2 biocatalyst was an effective catalyst for asymmetric reduction. This method provides an environmentally friendly method for the synthesis of optically pure alcohols and an alternative approach to chemical catalysts.
Chromoselective Photocatalysis Enables Stereocomplementary Biocatalytic Pathways**
Schmermund, Luca,Reischauer, Susanne,Bierbaumer, Sarah,Winkler, Christoph K.,Diaz-Rodriguez, Alba,Edwards, Lee J.,Kara, Selin,Mielke, Tamara,Cartwright, Jared,Grogan, Gideon,Pieber, Bartholom?us,Kroutil, Wolfgang
, p. 6965 - 6969 (2021)
Controlling the selectivity of a chemical reaction with external stimuli is common in thermal processes, but rare in visible-light photocatalysis. Here we show that the redox potential of a carbon nitride photocatalyst (CN-OA-m) can be tuned by changing the irradiation wavelength to generate electron holes with different oxidation potentials. This tuning was the key to realizing photo-chemo-enzymatic cascades that give either the (S)- or the (R)-enantiomer of phenylethanol. In combination with an unspecific peroxygenase from Agrocybe aegerita, green light irradiation of CN-OA-m led to the enantioselective hydroxylation of ethylbenzene to (R)-1-phenylethanol (99 % ee). In contrast, blue light irradiation triggered the photocatalytic oxidation of ethylbenzene to acetophenone, which in turn was enantioselectively reduced with an alcohol dehydrogenase from Rhodococcus ruber to form (S)-1-phenylethanol (93 % ee).
Highly Enantioselective Production of Chiral Secondary Alcohols with Candida zeylanoides as a New Whole Cell Biocatalyst
?ahin, Engin,Dertli, Enes
, (2017)
The increasing demand for biocatalysts in synthesizing enantiomerically pure chiral alcohols results from the outstanding characteristics of biocatalysts in reaction, economic, and ecological issues. Herein, fifteen yeast strains belonging to three food originated yeast species Candida zeylanoides, Pichia fermentans, and Saccharomyces uvarum were tested for their capability for asymmetric reduction of acetophenone to 1-phenylethanol as biocatalysts. Of these strains, C.?zeylanoides P1 showed an effective asymmetric reduction ability. Under optimized conditions, substituted acetophenones were converted to corresponding optically active secondary alcohols in up to 99% enantiomeric excess and at high yields. The preparative scale asymmetric bioreduction of 4-nitroacetophenone (1m) by C.?zeylanoides P1 gave (S)-1-(4-nitrophenyl)ethanol (2m) with 89% yield and >?99% enantiomeric excess. Compound 2m has been obtained in an enantiomerically pure and inexpensive form. Additionally, these results indicate that C.?zeylanoides P1 is a promising biocatalyst for the synthesis of chiral alcohols in industry.
A ruthenium catalyst with simple triphenylphosphane for the enantioselective hydrogenation of aromatic ketones
Zhou, Han,Huang, Hanmin
, p. 2253 - 2257 (2013)
An efficient Ru catalyst constructed from simple and commercially available triphenylphosphane and enantiopure (1S,1′S)-1,1′-biisoindoline (BIDN) was applied to the asymmetric hydrogenation of aromatic ketones. A range of simple aromatic ketones could be hydrogenated with good to excellent enantioselectivities (up to 95% ee). An appropriate enantioselective transition state was proposed to explain the high enantioselectivity obtained with this catalytic system. This study represents the first example to establish a practical Noyori-type catalyst with a simple achiral monophosphane for highly enantioselective hydrogenation. Keep it simple: An efficient Ru catalyst constructed from simple and commercially available triphenylphosphane and enantiopure (1S,1′S)-1,1′-biisoindoline (BIDN) was applied to the asymmetric hydrogenation of aromatic ketones. A range of simple aromatic ketones could be hydrogenated with good to excellent enantioselectivities (up to 95% ee).
Water-soluble arene ruthenium complexes containing a trans-1,2- diaminocyclohexane ligand as enantioselective transfer hydrogenation catalysts in aqueous solution
Canivet, Jerome,Labat, Gael,Stoeckli-Evans, Helen,Suess-Fink, Georg
, p. 4493 - 4500 (2005)
The cationic chloro complexes [(arene)Ru(H2N∩NH 2)Cl]+ (1: arene = C6H6; 2: arene = p-MeC6H4iPr; 3: arene = C6Me6) have been synthesised from the correspond
In situ measurement of the enantiomeric excess of alcohols and amines under asymmetric reduction reaction by 1H NMR
Ye, Xiaoxia,Lei, Xinxiang,Chen, Zhenfei,Zhang, Lixue,Zhang, Anjiang
, p. 3238 - 3241 (2010)
(Figure Presented) 1H NMR, in situ, determines the enantiomeric excess of reduced chiral alcohols or amines without adding any auxiliary and workup. The percent ee data determined by this method agree well with those given by HPLC. This approach may be potentially applicable to many asymmetric reductions.
Highly recoverable organoruthenium-functionalized mesoporous silica boosts aqueous asymmetric transfer hydrogenation reaction
Liu, Rui,Cheng, Tanyu,Kong, Lingyu,Chen, Chen,Liu, Guohua,Li, Hexing
, p. 55 - 61 (2013)
Exploring functionalized mesoporous silica to achieve enhanced catalytic activity and enantioselectivity in heterogeneous asymmetric catalysis presents a significant challenge that is critical for understanding the function of support and controlling chiral complexation behavior. In this contribution, by cooperative assembly of chiral 4-(trimethoxysilyl)ethyl)phenylsulfonyl-1,2- diphenylethylene-diamine and tetraethoxysilane followed by complexation with organoruthenium complex, we report a unique three-dimensional chiral organoruthenium-functionalized chrysanthemum-like mesoporous silica (CMS). As demonstrated in the studies, taking advantage of the active site-isolated chiral organoruthenium catalytic nature, this heterogeneous catalyst ArRuTsDPEN-CMS (Ar = hexamethylbenzene, TsDPEN = 4-methylphenylsulfonyl-1,2-diphenylethylene- diamine) displays enhanced catalytic activity and enantioselectivity in aqueous asymmetric transfer hydrogenation with extensive substrates. Furthermore, this heterogeneous catalyst can be conveniently recovered and reused at least 10 times without loss of its catalytic efficiency. These features render this catalyst particularly attractive in practice of organic synthesis in an environmentally friendly manner. Also, this outcome from the study clearly shows that the strategy described here offers a general approach to immobilization of chiral ligand-derived silane onto a functionalized mesoporous material with significant improving catalytic activity.
Asymmetric bioreduction of p-haloacetophenones by Mucor
Zhang, Zuohui,Liu, Xiongmin,Ma, Li,Zhuo, Meifang,Shen, Fang
, p. 323 - 328 (2013)
A number of p-haloacetophenones were asymmetrically bioreduced to their corresponding (S)-alcohols by Mucor sp. CG10 with good conversion and excellent enantioselectivity. The results showed that the electronic effects of the halogen substituent (X-group) affected the conversion of the substrates and the enantioselectivity of the reaction. The trend observed was as the X-group at the para-position became more electron donating from F, to Cl, Br and I, the conversion of substrates decreased, while the enantioselectivity increased.
Water-soluble chiral monosulfonamide-cyclohexane-1,2-diamine-RhCp* complex and its application in the asymmetric transfer hydrogenation (ATH) of ketones
Cortez, Norma A.,Aguirre, Gerardo,Parra-Hake, Miguel,Somanathan, Ratnasamy
, p. 4335 - 4338 (2007)
Monosulfonamide ligands with heteroatom/heterocyclic systems were derived from trans-(1R,2R)-cyclohexane-1,2-diamine and complexed with [Ru(benzene)Cl2]2, [Cp*RhCl2]2 in situ and used in the ATH of ar
Reduction of 4-Substituted Acetophenones by Yeast
Eichberger, Guenter,Faber, Kurt,Griengl, Herfried
, p. 1233 - 1236 (1985)
The velocity of reduction of 4-substituted acetophenones by baker's yeast is decreased by electron donating substituents.The steric course, howewer, is little influenced and (S)-1-arylethanols 2 are generally formed with over 90percent enantiomeric excess. - Keywords: Stereoselective reduction; (S)-1-Phenylethanol; Yeast
Highly enantiomeric reduction of acetophenone and its derivatives by locally isolated Rhodotorula glutinis
Zilbeyaz, Kani,Kurbanoglu, Esabi B.
, p. 849 - 854 (2010)
Ninety isolates of microorganisms belonging to different taxonomical groups (30 bacteria, 20 yeast, and 40 fungi) were previously isolated from various samples. These isolates were screened as reducing agents for acetophenone 1a to phenylethanol 2a. It was found that the isolate EBK-10 was the most effective biocatalyst for the enantioselective bioreduction of acetophenone. This isolate was identified as Rhodotorula glutinis by the VITEK 2 Compact system. The various parameters (pH 6.5, temperature 32°C, and agitation 200 rpm) of the bioreduction reaction was optimized, which resulted in conversions up to 100% with >99% enantiomeric excesses (ee) of the S-configuration. The preparative scale bioreduction of acetophenone 1a by R. glutinis EBK-10 gave (S)-1-phenylethanol 2a in 79% yield, complete conversion, and >99% ee. In addition, R. glutinis EBK-10 successfully reduced various substituted acetophenones.
Chiral Iron(II)-Catalysts within Valinol-Grafted Metal-Organic Frameworks for Enantioselective Reduction of Ketones
Akhtar, Naved,Antil, Neha,Begum, Wahida,Chauhan, Manav,Kumar, Ajay,Manna, Kuntal,Newar, Rajashree
, p. 10450 - 10459 (2021/08/31)
The development of highly efficient and enantioselective heterogeneous catalysts based on earth-abundant elements and inexpensive chiral ligands is essential for environment-friendly and economical production of optically active compounds. We report a strategy of synthesizing chiral amino alcohol-functionalized metal-organic frameworks (MOFs) to afford highly enantioselective single-site base-metal catalysts for asymmetric organic transformations. The chiral MOFs (vol-UiO) were prepared by grafting of chiral amino alcohol such as l-valinol within the pores of aldehyde-functionalized UiO-MOFs via formation of imine linkages. The metalation of vol-UiO with FeCl2 in THF gives amino alcohol coordinated octahedral FeII species of vol-FeCl(THF)3 within the MOFs as determined by X-ray absorption spectroscopy. Upon activation with LiCH2SiMe3, vol-UiO-Fe catalyzed hydrosilylation and hydroboration of a range of aliphatic and aromatic carbonyls to afford the corresponding chiral alcohols with enantiomeric excesses up to 99%. Vol-UiO-Fe catalysts have high turnover numbers of up to 15 ?000 and could be reused at least 10 times without any loss of activity and enantioselectivity. The spectroscopic, kinetic, and computational studies suggest iron-hydride as the catalytic species, which undergoes enantioselective 1,2-insertion of carbonyl to give an iron-alkoxide intermediate. The subsequent σ-bond metathesis between Fe-O bond and Si-H bond of silane produces chiral silyl ether. This work highlights the importance of MOFs as the tunable molecular material for designing chiral solid catalysts based on inexpensive natural feedstocks such as chiral amino acids and base-metals for asymmetric organic transformations.
Tridentate nitrogen phosphine ligand containing arylamine NH as well as preparation method and application thereof
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Paragraph 0095-0102; 0105-0109, (2021/06/26)
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.
Chitosan as a chiral ligand and organocatalyst: Preparation conditions-property-catalytic performance relationships
Kolcsár, Vanessza Judit,Sz?ll?si, Gy?rgy
, p. 7652 - 7666 (2021/12/13)
Chitosan is an abundant and renewable chirality source of natural origin. The effect of the preparation conditions by alkaline hydrolysis of chitin on the properties of chitosan was studied. The materials obtained were used as ligands in the ruthenium-catalysed asymmetric transfer hydrogenation of aromatic prochiral ketones and oxidative kinetic resolution of benzylic alcohols as well as organocatalysts in the Michael addition of isobutyraldehyde to N-substituted maleimides. The degrees of deacetylation of the prepared materials were determined by 1H NMR, FT-IR and UV-vis spectroscopy, the molecular weights by viscosity measurements, their crystallinity by WAXRD, and their morphology by SEM and TEM investigations. The materials were also characterized by Raman spectroscopy. The biopolymers which have molecular weights in a narrow (200-230 kDa) range and appropriate (80-95%) degrees of deacetylation were the most efficient ligands in the enantioselective transfer hydrogenation, whereas in the oxidative kinetic resolution the activity of the complexes and the stereoselectivity increased with the degree of deacetylation. The chirality of the chitosan was sufficient to obtain enantioselection in the Michael addition of isobutyraldehyde to maleimides in the aqueous phase. Interestingly, the biopolymer afforded the opposite enantiomer in excess compared to the monomer, d-glucosamine. In this reaction, good correlation between the degree of deacetylation and the catalytic activity was found. These results are novel steps in the application of this natural, biocompatible and biodegradable polymer in developing environmentally benign methods for the production of optically pure fine chemicals.
