- Identification of key residues in Debaryomyces hansenii carbonyl reductase for highly productive preparation of (S)-aryl halohydrins
-
Key residues of Debaryomyces hansenii carbonyl reductase in the determination of the reducing activity towards aryl haloketones were identified through combinatorial mutation of conserved residues. This study provides a green and efficient biocatalyst for the synthesis of (S)-aryl halohydrins.
- Xu, Guo-Chao,Shang, Yue-Peng,Yu, Hui-Lei,Xu, Jian-He
-
-
Read Online
- Copper(ii)-catalyzed enantioselective hydrosilylation of halo-substituted alkyl aryl and heteroaryl ketones: Asymmetric synthesis of (R)-fluoxetine and (S)-duloxetine
-
A set of reaction conditions has been established to facilitate the non-precious copper-catalyzed enantioselective hydrosilylation of a number of structurally diverse β-, γ- or ε-halo-substituted alkyl aryl ketones and α-, β- or γ-halo-substituted alkyl heteroaryl ketones under air to afford a broad spectrum of halo alcohols in high yields and good to excellent enantioselectivities (up to 99% ee). The developed procedure has been successfully applied to the asymmetric synthesis of antidepressant drugs (R)-fluoxetine and (S)-duloxetine, which highlighted its synthetic utility.
- Zhou, Ji-Ning,Fang, Qiang,Hu, Yi-Hu,Yang, Li-Yao,Wu, Fei-Fei,Xie, Lin-Jie,Wu, Jing,Li, Shijun
-
-
Read Online
- PEG600-carboxylates as efficient reusable reaction media and acylating agents for the resolution of sec-alcohols
-
Herein is presented a simple, attractive, and reusable methodology for one-pot resolution/separation of free sec-alcohols with enantiomeric excess (ee) values over 90% by the combination of sustainable acylating agents/solvents (polyethylene glycol derivatives) and an easily available and common biocatalyst (Candida antarctica lipase B, or CAL B) under irreversible conditions, along with a separation process by extraction or distillation. A scale-up reaction was carried out with the Fluoxetine precursor with ee values close to 90% for the R enantiomer.
- Monteiro, Carlos M.,Lourenco, Nuno M. T.,Ferreira, Frederico C.,Afonso, Carlos A. M.
-
-
Read Online
- Iminophenyl Oxazolinylphenylamine for Enantioselective Cobalt-Catalyzed Hydrosilylation of Aryl Ketones
-
A new family of chiral iminophenyl oxazolinylphenylamines (IPOPA) was designed and synthesized through three steps from commercially available starting materials. An efficient cobalt-catalyzed asymmetric hydrosilylation of simple ketones with a low catalyst loading of CoCl2 and IPOPA was developed to afford chiral alcohols in good yields with high enantioselectivities.
- Chen, Xu,Lu, Zhan
-
-
Read Online
- A new catalytic enantioselective reducing reagent system from (-)-α,α-diphenylpyrrolidinemethanol and 9-borabicyclo[3.3.1]nonane, especially effective for hindered and substituted aralkylketones
-
New catalytic enantioselective reduction systems were prepared from aminoalcohols and dialkylboranes, for the enantioselective reductions of prochiral aromatic ketones. Among these, the system prepared from (-)-α,α-diphenylpyrrolidinemethanol with 9-borabicyclo[3.3.1]nonane proved especially promising for such reductions. This complex catalyzes the reduction of prochiral aralkyl ketones to the corresponding alcohols with BH3-THF, with enantioselectivities 82-99.2%. Also, this catalyst is particularly effective for the more hindered and substituted aralkyl ketones. Various modifications in this new catalytic reduction system, such as changing reaction conditions, reducing agent and dialkylborane, were also examined.
- Kanth, Josyula V.B.,Brown, Herbert C.
-
-
Read Online
- Chiral terpene auxiliaries III: Spiroborate esters from (1R,2S,3R,5R)-3-amino-apopinan-2-ol as highly effective catalysts for asymmetric reduction of ketones with borane
-
New spiroborate esters, derived from terpene amino alcohols, (S)-prolinol, and 2-aminoethanol, were employed as catalysts in the borane reduction of acetophenone and other aryl alkyl and halogenated ketones. The corresponding alcohols were obtained in high yields and with enantioselectivities up to 98% ee. The influence of the amino alcohol and the diol moieties of spiroborate on the reaction selectivity was examined. The catalyst load, the nature of the solvent, the borane source, and the reaction conditions were also investigated.
- ?wiklińska, Marta,Krzemiński, Marek P.,Tafelska-Kaczmarek, Agnieszka
-
-
Read Online
- Pen G acylase catalyzed resolution of phenylacetate esters of secondary alcohols
-
Penicillin G acylase from E. coli (E.C. 3.5.1.11) immobilized on Eupergit C is used for the kinetic resolution of phenyl acetate esters of secondary alcohols of pharmaceutical interest.
- Baldaro,D'Arrigo,Pedrocchi-Fantoni,Rosell,Tagliani,Terreni,Servi
-
-
Read Online
- Efficient Synthesis of (R)-2-Chloro-1-(2,4-dichlorophenyl)ethanol with a Ketoreductase from Scheffersomyces stipitis CBS 6045
-
By enzyme screening, a ketoreductase cloned from Scheffersomyces stipitis CBS 6045 and named SsCR was identified that could catalyze the asymmetric hydrogenation of a variety of aromatic ketones. SsCR exhibited a specific activity of 65 U mg?1p
- Shang, Yue-Peng,Chen, Qi,Kong, Xu-Dong,Zhang, Yu-Jun,Xu, Jian-He,Yu, Hui-Lei
-
-
Read Online
- Chemoenzymatic synthesis of fluoxetine precursors. Reduction of β-substituted propiophenones
-
Five endophytic yeast strains isolated from edible plants were tested in the reduction β-chloro- and β-azidopropiophenone for the preparation of optically active fluoxetine precursors. The biotransformation rendered not only the corresponding chiral γ-substituted alcohols, but also unsubstituted alcohols and ketones. The product profile was studied and a plausible mechanism for the reductive elimination of the β-functional group is proposed.
- Coronel, Camila,Arce, Gabriel,Iglesias, Cesar,Noguera, Cynthia Magallanes,Bonnecarrere, Paula Rodriguez,Giordano, Sonia Rodriguez,Gonzalez, David
-
-
Read Online
- Enantioselective reduction of propiophenone formed from 3-chloropropiophenone and stereoinversion of the resulting alcohols in selected yeast cultures
-
Biotransformation of 3-chloro-1-phenylpropan-1-one 1 in sixteen selected cultures of yeast strains has been carried out. For most of the biocatalysts studied the substrate was fully consumed after 1-9 h of transformation, with the exception of the culture of Saccharomyces brasiliensis KCh 905, in which after 24 h trace amounts of the substrate were still visible (2%). However, apart from the expected enantiospecific reduction of the substrate to 3-chloro-1-phenylpropan-1-ol 3, the main biotransformation products comprised of a dehalogenation product - propiophenone 2 and the product of its reduction - 1-phenylpropan-1-ol 4. It was only in the cultures of five strains: Saccharomyces brasiliensis KCh 905, Rhodotorula marina KCh 77, Candida parapsilosis KCh 909, Candida viswanathii KCh 120, and Saccharomyces cerevisiae KCh 464 that 3-chloro-1-phenylpropan-1-ol 3 was observed in amounts of more than 10% of the product mixture. (S)-3-Chloro-1-phenylpropan-1-ol with ee = 91% was identified after 9 h of biotransformation in the culture of Candida viswanathii KCh 120, whereas (R)-3-chloro-1-phenylpropan-1-ol with ee = 28% was found in the culture of Aphanocladium album KCh 417. 1-Day biotransformation of propiophenone 2 in the cultures of Rhodotorula strains gave (S)-1-phenylpropan-1-ol 4 with a very high ee (95-99%) and 85-99% of substrate conversion, whereas transformation of this substrate in the cultures of Candida viswanathii KCh 120 and Candida parapsilosis KCh 909 led to (R)-1-phenylpropan-1-ol with ee = 98% and 97%, respectively. During biotransformation of propiophenone the percent composition of the reaction mixtures changed with time. Employment of the racemic mixture of 1-phenylpropan-1-ol 4 as a substrate for biotransformations allowed us to observe that the biocatalysts tested were capable of enantioselective oxidation of (S)-1-phenylpropan-1-ol. An exception was the culture of Rhodotorula glutinis KCh 242, in which after one day of biotransformation (S)-1-phenylpropan-1-ol was obtained with ee = 96%.
- Janeczko, Tomasz,Kostrzewa-Suslow, Edyta
-
-
Read Online
- Asymmetric Synthesis of 2-Aryl Substituted Oxetanes by Enantioselective Reduction of β-Halogenoketones using Lithium Borohydride modified with N,N'-Dibenzoylcystine
-
Optically active 2-aryl substituted oxetanes are synthesised in high enantiomeric excesses (up to 89percent e.e.) via enantioselective reduction of β-halogenoketones with lithium borohydride using (R,R')-N,N'-dibenzoylcystine and t-butyl alcohols as ligands.
- Soai, Kenso,Niwa, Seiji,Yamanoi, Takashi,Hikima, Hitoshi,Ishizaki, Miyuki
-
-
Read Online
- Enantioselective reduction of prochiral ketones using spiroborate esters as catalysts
-
Novel spiroborate esters derived nonracemic 1,2-aminoalcohols and ethylene glycol are reported as highly effective catalysts for the asymmetric borane reduction of a variety of prochiral ketones with borane-dimethyl sulfide complex at room temperature. Optically active alcohols were obtained in excellent chemical yields using 0.1-10 mol % of catalysts with up to 99% ee.
- Stepanenko, Viatcheslav,Jesús, Melvin De,Correa, Wildeliz,Guzmán, Irisbel,Vázquez, Cindybeth,de la Cruz, Wilanet,Ortiz-Marciales, Margarita,Barnes, Charles L.
-
-
Read Online
- Facile access to chiral alcohols with pharmaceutical relevance using a ketoreductase newly mined from Pichia guilliermondii
-
Chiral secondary alcohols with additional functional groups are frequently required as important and valuable synthons for pharmaceuticals, agricultural and other fine chemicals. With the advantages of environmentally benign reaction conditions, broad reaction scope, and high stereoselectivity, biocatalytic reduction of prochiral ketones offers significant potential in the synthesis of optically active alcohols. A CmCR homologous carbonyl reductase from Pichia guilliermondii NRRL Y-324 was successfully overexpressed. Substrate profile characterization revealed its broad substrate specificity, covering aryl ketones, aliphatic ketones and ketoesters. Furthermore, a variety of ketone substrates were asymmetrically reduced by the purified enzyme with an additionally NADPH regeneration system. The reduction system exhibited excellent enantioselectivity (>99% ee) in the reduction of all the aromatic ketones and ketoesters, except for 2-bromoacetophenone (93.5% ee). Semi-preparative reduction of six ketones was achieved with high enantioselectivity (>99% ee) and isolation yields (>80%) within 12 h. This study provides a useful guidance for further application of this enzyme in the asymmetric synthesis of chiral alcohol enantiomers. Copyright
- Xu, Guochao,Yu, Huilei,Xu, Jianhe
-
-
Read Online
- ENANTIOSELECTIVE AND PRACTICAL SYNTHESES OF R- AND S-FLUOXETINES
-
An efficient synthetic route to either R- or S-fluoxetine is described which depends on the use of a chiral, enzyme-like catalyst (chemzyme) to establish the stereocenter and which makes these important therapeutic agents readily available in enantiomerically pure form.
- Corey, E. J.,Reichard, Gregory A.
-
-
Read Online
- 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
-
-
Read Online
- Corey-itsuno reduction of ketones: A development of safe and inexpensive process for synthesis of some API intermediates
-
A safe and inexpensive procedure for asymmetric reduction of ketones using in situ prepared N,N-diethylaniline borane (DEANB) and oxazaborolidine catalyst from sodium borohydride, N,N-diethylaniline hydrochloride and (S)-α,α-diphenylprolinol is described. This protocol is demonstrated successfully to manufacture enantiopure dapoxetine at the plant scale.
- Mahale, Rajendra D.,Chaskar, Sudhir P.,Patil, Kiran E.,Maikap, Golak C.,Gurjar, Mukund K.
-
-
Read Online
- Diphenyloxazaborolidine a new catalyst for enantioselective reduction of ketones
-
A variety of ketones can be reduced in high enantioselectivity with the oxazaborolidines derived from commercially available erythro aminodiphenylethanol.
- Quallich, George J.,Woodall, Teresa M.
-
-
Read Online
- Mesoporous silica KIT-6 supported superparamagnetic CuFe2O 4 nanoparticles for catalytic asymmetric hydrosilylation of ketones in air
-
A diverse range of prochiral ketones were reduced in air with high yields and good-to-excellent enantioselectivities (up to 97% ee) in the presence of a heterogeneous catalyst system, which was in situ formed from catalytic amounts of superparamagnetic CuFe2O4 nanoparticles supported on mesoporous silica KIT-6 and non-racemic dipyridylphosphine ligand, the stoichiometric hydride donor polymethylhydrosiloxane (PMHS) as well as certain amounts of additives. The magnetically separable catalysts could be efficiently reused 4 times without apparent loss of both the activity and enantioselectivity. the Partner Organisations 2014.
- Li, Min,Li, Bin,Xia, Hong-Feng,Ye, Danru,Wu, Jing,Shi, Yifeng
-
-
Read Online
- Ultrafast Iron-Catalyzed Reduction of Functionalized Ketones: Highly Enantioselective Synthesis of Halohydrines, Oxaheterocycles, and Aminoalcohols
-
A molecularly defined chiral boxmi iron alkyl complex catalyzes the hydroboration of various functionalized ketones and provides the corresponding chiral halohydrines, oxaheterocycles (oxiranes, oxetanes, tetrahydrofurans, and dioxanes) and amino alcohols with excellent enantioselectivities (up to >99 %ee) and conversion efficiencies at low catalyst loadings (as low as 0.5 mol %). Turnover frequencies of greater than 40000 h?1 at ?30 °C highlight the activity of this earth-abundant metal catalyst which tolerates a large number of functional groups.
- Blasius, Clemens K.,Vasilenko, Vladislav,Gade, Lutz H.
-
-
Read Online
- Catalytic enantioselective synthesis of secondary alcohols using C2-symmetric diamino diol ligands
-
A new class of diamino diols was evaluated as catalytic ligands in the enantioselective borane reduction of aromatic ketones and the enantioselective ethylation of arylaldehydes with diethylzinc. By variation of the substitution pattern on the ketone, e.e.s of up to 94% could be obtained by in situ borane reduction using 0.025 equiv. of the ligand at 35°C in THF. N,N,N′,N′-Tetramethyldiamino diol and N,N′-dialkyl diamino diol were used as promoters for the enantioselective addition of diethylzinc reagent to the arylaldehyde, where use of 0.1 equiv. of N,N,N′,N′-tetramethyl diamino diol as catalyst in the addition of diethylzinc to arylaldehyde achieved e.e.s of up to 98%.
- Jiang, Biao,Feng, Yan,Hang, Jian-Feng
-
-
Read Online
- Asymmetric reduction of prochiral ketones using in situ generated oxazaborolidine derived from (1S,2S,3R,4R)-3-amino-7,7-dimethoxynorbornan-2-ol. An efficient synthesis of enantiopure (R)-tomoxetine
-
In this work, we report our results on the asymmetric reduction of prochiral aromatic and aliphatic ketones 3, 5-8 catalyzed by the novel in situ generated oxazaborolidine 2 derived from (1S,2S,3R,4R)-3-amino-7,7- dimethoxybornan-2-ol (1) and BH3?Me2S. This methodology was applied to the synthesis of the anti-depressant drug (R)-tomoxetine in three steps and 47% overall yield from 3-chloropropiophenone (3h). Catalytic asymmetric reduction of prochiral ketones was examined in the presence of chiral oxazaborolidine catalyst 2 prepared in situ from (1S,2S,3R,4R)-3-amino-7,7-dimethoxynorbornan-2-ol (1). The optically active secondary alcohols were generally obtained in moderate to high enantiomeric excesses (ee 43-95%) and good yields (75-94%), except for ketones bearing electron-withdrawing groups. The methodology was applied to the synthesis of enantiopure (R)-tomoxetine, a potent anti-depressant drug.
- Lapis, Alexandre A. M.,De Fátima, ?ngelo,Martins, José E. D.,Costa, Valentim E. U.,Pilli, Ronaldo A.
-
-
Read Online
- Preparation method of cefamoxetine hydrochloride
-
The invention discloses a preparation method of tamoxidectin hydrochloride, belongs to the technical field of drug synthesis, and uses 3 - chlorine -1 - phenylpropanone as a raw material to undergo a reduction reaction. The synthesis route has the advantages of few reaction steps, mild reaction conditions,3 - simple 2 - operation, cheap -3 - and easily available raw materials, and low production cost 3 - and -1 - R-chloro - N - phenylpropanone is used as a raw material.
- -
-
Paragraph 0008; 0018; 0021; 0024; 0027
(2021/10/27)
-
- Total Synthesis of Meayamycin B
-
Meayamycin B is currently the most potent modulator of the splicing factor 3b subunit 1 and used by dozens of research groups. However, current supply for this natural product analogue is limited because of the lengthy synthetic scheme. Here, we report a more concise, more cost-effective, and greener synthesis of this compound by developing and employing a novel asymmetric reduction of a prochiral enone to afford an allylic alcohol with high enantioselectivity. In addition to this reaction, this synthesis highlights a scalable Mukaiyama aldol reaction, Nicolaou-type epoxide opening reaction, stereoselective Corey-Chaykovsky-type reaction, and a modified Horner-Wadsworth-Emmons Z-selective olefination. We also discuss a Z-E isomerization during the α,β-unsaturated amide formation. The new synthesis of meayamycin B consists of 11 steps in the longest linear sequence and 24 total steps.
- Basu, Upamanyu,Bressin, Robert K.,Koide, Kazunori,Osman, Sami,Pohorilets, Ivanna
-
supporting information
p. 4637 - 4647
(2020/05/01)
-
- Two enantiocomplementary ephedrine dehydrogenases from arthrobacter sp. TS-15 with broad substrate specificity
-
The recently identified pseudoephedrine and ephedrine dehydrogenases (PseDH and EDH, respectively) from Arthrobacter sp. TS-15 are NADH-dependent members of the oxidoreductase superfamily of short-chain dehydrogenases/reductases (SDRs). They are specific for the enantioselective oxidation of (+)-(S) N-(pseudo)ephedrine and (-)-(R) N-(pseudo)ephedrine, respectively. Anti-Prelog stereospecific PseDH and Prelog-specific EDH catalyze the regio- A nd enantiospecific reduction of 1-phenyl-1,2-propanedione to (S)-phenylacetylcarbinol and (R)-phenylacetylcarbinol with full conversion and enantiomeric excess of >99%. Moreover, they perform the reduction of a wide range of aryl-aliphatic carbonyl compounds, including ketoamines, ketoesters, and haloketones, to the corresponding enantiopure alcohols. The highest stability of PseDH and EDH was determined to be at a pH range of 6.0-8.0 and 7.5-8.5, respectively. PseDH was more stable than EDH at 25 °C with half-lives of 279 and 38 h, respectively. However, EDH is more stable at 40 °C with a 2-fold greater half-life than at 25 °C. The crystal structure of the PseDH-NAD+ complex, refined to a resolution of 1.83 ?, revealed a tetrameric structure, which was confirmed by solution studies. A model of the active site in complex with NAD+ and 1-phenyl-1,2-propanedione suggested key roles for S143 and W152 in recognition of the substrate and positioning for the reduction reaction. The wide substrate spectrum of these dehydrogenases, combined with their regio- A nd enantioselectivity, suggests a high potential for the industrial production of valuable chiral compounds.
- Shanati, Tarek,Lockie, Cameron,Beloti, Lilian,Grogan, Gideon,Ansorge-Schumacher, Marion B.
-
p. 6202 - 6211
(2019/08/15)
-
- Iridium-Catalyzed Asymmetric Hydrogenation of Halogenated Ketones for the Efficient Construction of Chiral Halohydrins
-
Iridium-catalyzed asymmetric hydrogenation of prochiral halogenated ketones was successfully developed to prepare various chiral halohydrins with high reactivities and excellent enantioselectivities under basic reaction condition (up to >99% conversion, 99% yield, >99% ee). Moreover, gram-scale experiment was performed well in the presence of just 0.005 mol% (S/C=20 000) Ir/f-amphox catalyst with 99% yield and >99% ee. (Figure presented.).
- Yin, Congcong,Wu, Weilong,Hu, Yang,Tan, Xuefeng,You, Cai,Liu, Yuanhua,Chen, Ziyi,Dong, Xiu-Qin,Zhang, Xumu
-
supporting information
p. 2119 - 2124
(2018/04/30)
-
- Stereoselectivity arone derivatives of hydrogenation method
-
The invention discloses a highly stereoscopic selective hydrogenation method for aromatic ketone derivatives. The method comprises the following steps: (1) placing a metal precursor [RhCl2Cp*]2 and a ligand shown in the formula (XIV) into a reaction vesse
- -
-
Paragraph 0095; 0096; 0097; 0098; 0099
(2017/10/20)
-
- Nearly aqueous-like activity of lipoprotein lipase treated with glucose-headed surfactant in organic solvent
-
In this work, we explored the activation of a lipoprotein lipase from Burkholderia species by glucose-headed surfactants (GHSs) for enhancing its catalytic activity in organic solvent. Three GHSs were prepared and then tested as the additives for inducing the activation of lipoprotein lipase. The kinetic parameters of GHS-treated lipoprotein lipase were determined for the hydrolysis or alcoholysis of p-nitrophenyl acetate. It was found that GHS-treated lipoprotein lipase was 4 to 5 orders of magnitude more active than its native counterpart in organic solvent. Such a dramatic activity enhancement was largely the result of a huge increase in the turnover frequency kcat. Surprisingly, the kcat values in organic solvent were one order of magnitude greater than their aqueous counterparts. As a result, the kcat/Km of GHS-treated lipoprotein lipase in organic solvent became comparable to the aqueous level within one order of magnitude. We thus have demonstrated for the first time that a lipase can display nearly aqueous-like activity in organic solvent. As an illustrative application of GHS-treated lipoprotein lipase, we performed the dynamic kinetic resolution of two secondary alcohols, which provided the products of high enantiopurity (98–99%ee) with high yields (90–91%).
- Oh, Yeonock,Choi, Yoon Kyung,Yun, Inyeol,Lee, Eungyeong,Kim, Kyungwoo,Kim, Mahn-Joo
-
p. 148 - 153
(2016/11/04)
-
- Design, synthesis, and biological evaluation of novel thiazolidinediones as PPAR3/FFAR1 dual agonists
-
Diabetes mellitus is a chronic metabolic disorder that affects more than 180 million people worldwide. Peroxisome proliferator activated receptors (PPARs) are a group of nuclear receptors that have been targeted by the thiazolidinedione (TZD) class of compounds for the management of type II diabetes. PPAR3 is known to regulate adipogenesis and glucose metabolism. Another emerging target for the design of antidiabetic agents is the free fatty acid receptor 1 (FFAR1), previously known as GPR40. Agonists of this receptor were found to enhance insulin secretion in diabetic patients. It has been reported that some thiazolidinediones (TZDs) activate FFAR1 with micromolar potency. In this study, based on docking studies into the crystal structure of PPAR3 and a homology model of FFAR1, nineteen compounds were designed, synthesized, and biologically tested for agonistic activity on both receptors. Nine compounds showed promising dual activity, with two compounds, 11a and 5b, having affinities in the low micromolar range on both targets. These molecules represent the first antidiabetic agents that could act as insulin sensitizers as well as insulin secretagogues.
- Darwish, Khaled M.,Salama, Ismail,Mostafa, Samia,Gomaa, Mohamed S.,Helal, Mohamed A.
-
p. 157 - 172
(2016/01/16)
-
- Method for preparation of optically active 3-amino-arylpropan-1-ol derivatives from 3-chloro-1-arylpropan-1-ol derivatives
-
The present invention relates to a method for preparing an optically active 3-amino-1-arylpropan-1-ol derivative, including the step of making an optically active 3-chloro-1-arylpropan-1-ol compound react with an amine derivative. The method according to the present invention allows direct amination of an optically active 3-chloro-1-arylpropan-1-ol derivative through a single-step reaction. Thus, it is possible to provide a compound functioning as a key intermediate of various optically active molecules through a simple process with high yield, while maintaining the optical purity of the reactant. Therefore, the method may be used for preparing medicines, such as (S)-Duloxetin, (R)-Fluoxetine, (R)- Tomoxetine or (R)- Nisoxetine, with high optical purity by combining the method for preparing an optically active 3-chloro-1-arylpropan-1-ol derivative as a reactant of the method with an additional substitution reaction.(AA) Tomoxetine(BB) Fluoxetine(CC) 3-amino-1-propanol(DD) Nisoxetine(EE) DuloxetineCOPYRIGHT KIPO 2016
- -
-
Paragraph 0069-0072
(2016/12/01)
-
- Chiral preparation method of dapoxetine hydrochloride key intermediate
-
The invention discloses a chiral preparation method of a dapoxetine hydrochloride key intermediate.According to the preparation method, with 3-chloropropiophenone as a raw material and (+)2-ethylmorphine-B-chlorodiisopinocampherylborane Eap2BCl as a reduc
- -
-
Paragraph 0037; 0049; 0050
(2017/02/09)
-
- A convenient enantioselective CBS-reduction of arylketones in flow-microreactor systems
-
A convenient, versatile, and green CBS-asymmetric reduction of aryl and heteroaryl ketones has been developed by using the microreactor technology. The study demonstrates that it is possible to handle borane solution safely within microreactors and that the reaction performs well using 2-MeTHF as a greener solvent.
- De Angelis, Sonia,De Renzo, Maddalena,Carlucci, Claudia,Degennaro, Leonardo,Luisi, Renzo
-
supporting information
p. 4304 - 4311
(2016/05/24)
-
- Cobalt-catalyzed asymmetric hydroboration of aryl ketones with pinacolborane
-
The highly enantioselective cobalt-catalyzed hydroboration reaction of aryl ketones with HBpin was developed using iminopyridine oxazoline ligands. Halides, amines, ethers, sulfides, esters and amides are well tolerated under the mild reaction conditions, demonstrating its synthetic advantage. Substituted diaryl ketones could also be hydroborated with high enantioselectivity.
- Guo, Jun,Chen, Jianhui,Lu, Zhan
-
supporting information
p. 5725 - 5727
(2015/03/30)
-
- A method for preparing optically active 3-amino-1-phenylpropanol derivatives as an intermediate and a method for preparing optically active pharmaceutical products using the same
-
The present invention relates to a method for preparing a 3-amino-1-phenylpropanol derivative having (R) or (S) optical activity with 80% or more of an enantiomeric excess (ee), which includes a step of performing an asymmetric reduction reaction in the presence of a spiroborate ester catalyst and a hydrogen donor. The invention also relates to a method for preparing an optically active pharmaceutical product, which includes a step of preparing a (R)- or (S)-3-amino-1-phenylpropanol derivative, that is an intermediate, by using the catalyst.(AA) 3-amino-1-phenylpropanol(BB) Tomoxetine(CC) Nisoxetine(DD) FluoxetineCOPYRIGHT KIPO 2016
- -
-
Paragraph 0143; 0156-0158
(2016/11/09)
-
- Identification of an ε-keto ester reductase for the efficient synthesis of an (R)-α-lipoic acid precursor
-
Abstract A novel reductase (CpAR2) with unusually high activity toward an ε-keto ester, ethyl 8-chloro-6-oxooctanoate, was isolated from Candida parapsilosis. The asymmetric reduction of ethyl 8-chloro-6-oxooctanoate using Escherichia coli cells coexpressing CpAR2 and glucose dehydrogenase genes gave ethyl (R)-8-chloro-6-hydroxyoctanoate, a key precursor for the synthesis of (R)-α-lipoic acid, in high space-time yield (530 gL-1d-1) and with excellent enantiomeric excess (>99%). This bioprocess was shown to be viable on a 10-L scale. This method provides a greener and more cost-effective method for the industrial production of (R)-α-lipoic acid.
- Zhang, Yu-Jun,Zhang, Wen-Xia,Zheng, Gao-Wei,Xu, Jian-He
-
supporting information
p. 1697 - 1702
(2015/06/02)
-
- Asymmetric transfer hydrogenation of aromatic ketones catalyzed by new chiral C2-symmetric bis(sulfonyl) tetraaza ligands complexed with [Ru(η6-p-cymene)Cl2]2 in water
-
In this report, a new series of C2-symmetric bis(sulfonyl) tetraaza ligands were synthesized from (1S,2S)-1,2-diarylethylenediamine analogues and tested in the asymmetric transfer hydrogenation (ATH) of aromatic ketones by complexing with [Ru(η6-p-cymene)Cl2]2 employing sodium formate as hydrogen source in neat water. A moderate to excellent conversion (～99.8 %) and overall satisfying enantioselectivity (～92.8 %) were obtained with varied electronic and steric effects of the substituents on ligands and substrates.
- Liu, Xungao,Zhang, Tian,Hu, Yingying,Shen, Liang
-
p. 1289 - 1295
(2014/07/21)
-
- Harnessing the ortho-directing ability of the azetidine ring for the regioselective and exhaustive functionalization of arenes
-
This work demonstrates how the directing ability of the azetidine ring could be useful for regioselective ortho-C-H functionalization of aryl compounds. Robust polar organometallic (lithiated) intermediates are involved in this synthetic strategy. The reagent n-hexyllithium emerged as a safer, yet still effective, basic reagent for the hydrogen/lithium permutation relative to the widely used reagent nBuLi. Two different reaction protocols were discovered for regioselective lithiation at the ortho positions adjacent to the azetidine ring, which served as a toolbox when other competing directing groups were installed on the aromatic ring. The coordinating ability of the azetidine nitrogen atom, as well as the involvement of dynamic phenomena related to the preferential conformations of 2-arylazetidine derivatives, were recognized to be responsible for the observed reactivity and regioselectivity. A site-selective functionalization of the aromatic ring was achieved for aryl azetidines with either coordinatively competent groups (e.g. methoxy) or inductively electron-withdrawing substituents (e.g. chlorine and fluorine). By fine-tuning the reaction conditions, regioselective introduction of several substituents on the aromatic ring could be realized. Several substitution patterns were accomplished, which included 1,2,3-trisubstitution, 1,2,3,4-tetrasubstitution, and 1,2,3,4,5-pentasubstitution, up to the exhaustive substitution of the aromatic ring.
- Zenzola, Marina,Degennaro, Leonardo,Trinchera, Piera,Carroccia, Laura,Giovine, Arianna,Romanazzi, Giuseppe,Mastrorilli, Piero,Rizzi, Rosanna,Pisano, Luisa,Luisi, Renzo
-
p. 12190 - 12200
(2015/03/31)
-
- Lipase-catalyzed synthesis of both enantiomers of 3-chloro-1-arylpropan-1- ols
-
The lipase-catalyzed synthesis of both enantiomers of 3-chloro-1-(4- fluorophenyl)propan-1-ol, 3-chloro-1-(4-iodophenyl)propan-1-ol, and 3-chloro-1-phenylpropan-1-ol is described. The procedure is based on the enantiomer-selective acylation of the racemic alcohols in presence of lipase from Pseudomonas fluorescens (LAK) followed by the lipase from Candida rugosa (CRL) mediated hydrolysis of previously obtained enantiomerically enriched 1-aryl-3-chloropropyl esters. For the production of enantiopure (S)-1-aryl-3-chloropropan-1-ols (99% ee, 34-42% yield) the reactions were stopped at higher conversions than the theoretical optimum of 50%, while for enantiopure (R)-1-aryl-3-chloropropyl acetates (99% ee) the reactions were stopped at lower conversions. The latter compounds were enzymatically hydrolyzed into the corresponding (R)-1-aryl-3-chloropropan-1-ols (97-99% ee, 18-24% yield). The absolute configuration of the resolution products was determined by VCD measurements combined with quantum chemical calculations. Georg Thieme Verlag Stuttgart - New York.
- Pop, Laura Ancua,Czompa, Andrea,Paizs, Csaba,Toa, Monica Ioana,Vass, Elemer,Matyus, Peter,Irimie, Florin-Dan
-
experimental part
p. 2921 - 2928
(2011/10/13)
-
- Asymmetric transfer hydrogenation of ketones in aqueous solution catalyzed by rhodium(III) complexes with C2-symmetric fluorene-ligands containing chiral (1R,2R)-cyclohexane-1,2-diamine
-
Two C2-symmetric bis(sulfonamide) ligands containing fluorene-chiral (1R,2R)-cyclohexane- 1,2-diamine were complexed to Rh III(Cp*) and used as catalyst to reduce aromatic ketones. The corresponding chiral secondary alcohols were obtained in 87-100percent ee and 85-99percent yield, under asymmetric transfer hydrogenation (ATH) conditions using aqueous sodium formate as the hydride source. With acetophenone, 94percent ee and 86-97percent yield was achieved with substrate/catalyst (S/C) ratio of 10,000.
- Montalvo-Gonza?lez, Rube?n,Cha?vez, Daniel,Aguirre, Gerardo,Parra-Hakea, Miguel,Somanathan, Ratnasamy
-
experimental part
p. 431 - 435
(2010/07/16)
-
- Synthesis of chiral aromatic alcohols: Use of new C2-symmetric RhIIICp*, RuII(cymene), or RuII(benzene) complexes containing chiral diaminocyclohexane ligand as asymmetric transfer hydrogenation catalyst
-
Twelve chiral secondary alcohols were synthesized by asymmetric transfer hydrogenation (ATH) using C2-symmetric bis(sulfonamide) ligand (2) derived from (1R,2R)-cyclohexane-1,2-diamine and complexed with [RhCl 2CP*]2, [RuCl2(cymene)] 2, or [RuCl2(benzene)]2 and then used in situ in the reduction of prochiral ketones. The alcohols were obtained in 85-99% yield and 90-99% enantioselectivity with isopropanol as the hydrogen source. Two-fold rate enhancement and better yields were achieved (88-99%) with 80-99% enantioselectivity using the complex [RhCl2CP*] 2 and aqueous sodium formate as the hydrogen source.
- Montalvo-Gonzalez, Ruben,Chavez, Daniel,Aguirre, Gerardo,Parra-Hake, Miguel,Somanathan, Ratnasamy
-
experimental part
p. 2737 - 2746
(2009/12/06)
-
- Organic metal compound and process for preparing optically-active alcohols using the same
-
The present invention provides an asymmetric reduction catalyst effective in preparing optically-active alcohol compounds having various functional groups, and a process for preparing optically-active alcohol compounds using said asymmetric reduction catalyst. The organic metal compound of the present invention is represented by the following general formula (1): wherein R1 and R2 may be mutually identical or different, and are an alkyl group, a phenyl group, a naphthyl group, a cycloalkyl group, or an alicyclic ring formed by binding R1 and R2, which may have a substituent; R3 is a hydrogen atom or an alkyl group; Cp is a cyclopentadienyl group, which may have a substituent, bound to M1 via a π bond; X1 is a halogen atom or a hydrido group; M1 is rhodium or iridium; and * denotes asymmetric carbon.
- -
-
Page/Page column 8; 14
(2009/04/24)
-
- Enantioselective, ketoreductase-based entry into pharmaceutical building blocks: Ethanol as tunable nicotinamide reductant
-
(Chemical Equation Presented) The use of NADH- and NADPH-dependent ketoreductases to access enantioenriched pharmaceutical building blocks is reported. Seven structurally diverse synthons are obtained, including those for atomoxetine (KRED 132), talampanel (RSt-ADH and CPADH), Dolastatin (KRED 132), and fluoxetine (KRED 108/132). Ethanol may be used as stoichiometric reductant, regenerating both nicotinamide cofactors, particularly under four-electron redox conditions. Its favorable thermodynamic and economic profile, coupled with its advantageous dual cosolvent role, suggests a new application for biomass-derived ethanol.
- Broussy, Sylvain,Cheloha, Ross W.,Berkowitz, David B.
-
supporting information; experimental part
p. 305 - 308
(2009/07/18)
-
- Enzymatic production of l-menthol by a high substrate concentration tolerable esterase from newly isolated Bacillus subtilis ECU0554
-
Enzymatic preparation of l-menthol has been attracting much attention in the flavor and fragrance industry. A new ideal strain, Bacillus subtilis ECU0554, which exhibited high hydrolytic activity and excellent enantioselectivity towards l-menthyl ester, has been successfully isolated from soil samples through enrichment culture and identified as Bacillus subtilis by 16S rDNA gene sequencing. The esterase extracted from B. subtilis ECU0554 (BSE) showed the best catalytic properties (E > 200) for dl-menthyl acetate among the five menthyl esters examined. Enantioselective hydrolysis of 100 mM dl-menthyl acetate at 30°C and pH 7.0, using crude BSE as biocatalyst and 10% ethanol (v/v) as cosolvent, resulted in 49.0% conversion (3 h) and 98.0% ee for the l-menthol produced, which were much better than those using commercial enzymes tested. Moreover, BSE exhibited strong tolerance against high substrate concentration (up to 500 mM), and the concentration of l-menthol produced could reach as high as 182 mM, and more importantly, the optical purity of l-menthol produced was kept above 97% ee, which were not found in previous reports. These results imply that BSE is a potentially promising bio-catalyst for the large-scale enzymatic preparation of l-menthol. Using this excellent biocatalyst, the enzymatic production of l-menthol will become a mild, efficient, inexpensive and easy-to-use "green chemistry" methodology.
- Zheng, Gao-Wei,Yu, Hui-Lei,Zhang, Jian-Dong,Xu, Jian-He
-
experimental part
p. 405 - 414
(2009/11/30)
-
- Highly enantioselective carbonyl reduction with borane catalyzed by chiral spiroborate esters derived from chiral beta-aminoalcohols
-
Novel spiroborate esters derived from non-recemic 1,2-amino alcohols were examined as chiral catalyst in the borane reduction of acetophenone and other aromatic ketones at room temperature. The optically active alcohols were obtained in excellent chemical yields and up to 99% ee with less than 10% catalyst.
- -
-
Page/Page column 7
(2008/12/08)
-
- Synthesis and activity of 1-(3-amino-1-phenylpropyl)indolin-2-ones: A new class of selective norepinephrine reuptake inhibitors
-
Norepinephrine and serotonin play an important role in a wide variety of biological processes and are implicated in a number of neurological disorders. A novel class of 1-(3-amino-1-phenylpropyl)indolin-2-ones was designed and synthesized that displays po
- McComas, Casey C.,Vu, An T.,Mahaney, Paige E.,Cohn, Stephen T.,Fensome, Andrew,Marella, Michael A.,Nogle, Lisa,Trybulski, Eugene J.,Ye, Fei,Zhang, Puwen,Alfinito, Peter,Bray, Jenifer,Johnston, Grace,Koury, Elizabeth,Deecher, Darlene C.
-
scheme or table
p. 4929 - 4931
(2009/05/07)
-
- Applications of asymmetric hydrosilylations mediated by catalytic (DTBM-SEGPHOS)CuH
-
Several aryl ketone precursors useful in the synthesis of known physiologically active compounds have been reduced to the corresponding nonracemic alcohols. The previously reported combination of a catalytic quantity of (R)-(-)-DTBM-SEGPHOS-ligated CuH an
- Lipshutz, Bruce H.,Lower, Asher,Kucejko, Robert J.,Noson, Kevin
-
p. 2969 - 2972
(2007/10/03)
-
- New atropisomeric biaryl derivatives of 4-aminopyridine - Identification of an improved nucleophilic catalyst for asymmetric acylation of sec-alcohols
-
The synthesis, CSP-HPLC resolution, and absolute configuration assignment of a series of 4-dialkylaminopyridine-based atropisomeric biaryls are described. Screening of these enantiomerically pure catalysts, which differ only in the nature of the 4-dialkylamino substituent, for the kinetic resolution of 1-(1-naphthyl)ethanol reveals the importance of this group on the selectivity of catalysis. The di-n-butylamino derivative displays the most favourable catalytic profile. The utility of this catalyst for the kinetic resolution of a selection of sec-alcohols, including a precursor for the synthesis of the antidepressant fluoxetine hydrochloride (Prozac) are reported. The possible role of the dialkylamino group in chirality transfer is discussed.
- Spivey, Alan C.,Leese, David P.,Zhu, Fujiang,Davey, Stephen G.,Jarvest, Richard L.
-
p. 4513 - 4525
(2007/10/03)
-
- Aminocyclopentadienyl Ruthenium Complexes as Racemization Catalysts for Dynamic Kinetic Resolution of Secondary Alcohols at Ambient Temperature
-
Aminocyclopentadienyl ruthenium complexes, which can be used as room-temperature racemization catalysts with lipases in the dynamic kinetic resolution (DKR) of secondary alcohols, were synthesized from cyclopenta-2,4-dienimines, Ru3(CO)12, and CHCl 3: [2,3,4,5-Ph4(η5-C 4CNHR)]Ru-(CO)2Cl (4: R = i-Pr; 5: R = n-Pr; 6: R = t-Bu), [2,5-Me2-3,4-Ph2(η5-C 4CNHR)]Ru(CO)2Cl (7: R = i-Pr; 8: R = Ph), and [2,3,4,5-Ph4(η5-C4CNHAr)]Ru(CO) 2Cl (9: Ar =p-NO2C6H4; 10: Ar = p-ClC6H4; 11: Ar = Ph; 12: Ar = p-OMeC6H 4; 13: Ar = p-NMe2C6H4). The tests in the racemization of (S)-4-phenyl-2-butanol showed that 7 is the most active catalyst, although the difference decreased in the DKR. Complex 4 was used in the DKR of various alcohols; at room temperature, not only simple alcohols but also functionalized ones such as allylic alcohols, alkynyl alcohols, diols, hydroxyl esters, and chlorohydrins were successfully transformed to chiral acetates. In mechanistic studies for the catalytic racemization, ruthenium hydride 14 appeared to be a key species. It was the major organometallic species in the racemization of (S)-1-phenylethanol with 4 and potassium tert-butoxide. In a separate experiment, (S)-1-phenylethanol was racemized catalytically by 14 in the presence of acetophenone.
- Choi, Jun Ho,Choi, Yoon Kyung,Kim, Yu Hwan,Park, Eun Sil,Kim, Eun Jung,Kim, Mahn-Joo,Park, Jaiwook
-
p. 1972 - 1977
(2007/10/03)
-
- Asymmetric reduction of ketones via whole cell bioconversions and transfer hydrogenation: Complementary approaches
-
Prochiral aryl and dialkyl ketones were enantioselectively reduced to the corresponding alcohols using whole cells of the white-rot fungus Merulius tremellosus ono991 as a biocatalytic reduction system and ruthenium(II)-amino alcohol and iridium(I)-amino sulfide complexes as metal catalysts in asymmetric transfer hydrogenation. Comparison of the results showed that the corresponding chiral alcohols could be obtained with moderate to high enantioselectivities (e.e.s of up to 98%). The biocatalytic and transfer hydrogenation approaches appear to be complementary. The biocatalytic approach is the most suitable for the enantioselective reduction of chloro-substituted (aryl) ketones, whereas in the reduction of α,β-unsaturated compounds excellent results were obtained using the catalytic hydrogenation protocol.
- Hage, Annemarie,Petra, Danielle G.I.,Field, Jim A.,Schipper, Dick,Wijnberg, Joannes B.P.A.,Kamer, Paul C.J.,Reek, Joost N.H.,Van Leeuwen, Piet W.N.M.,Wever, Ron,Schoemaker, Hans E.
-
p. 1025 - 1034
(2007/10/03)
-
- Chemoenzymatic synthesis of the non-tricyclic antidepressants Fluoxetine, Tomoxetine and Nisoxetine
-
3-Chloro-1-phenylpropan-1-ol and the corresponding butanoate, 3-chloro-1-phenyl-1-propyl butanoate, were kinetically resolved using lipase B from Candida antarctica catalysis by transesterification and hydrolysis respectively. The resulting chiral building blocks (S)- and (R)-3-chloro-1-phenylpropanol were converted into both enantiomers of the antidepressant drugs, Fluoxetine, Tomoxetine and Nisoxetine. The Royal Society of Chemistry 2000.
- Liu, Hui-Ling,Hoff, Bard Helge,Anthonsen, Thorleif
-
p. 1767 - 1769
(2007/10/03)
-
- Hydrolases in organic synthesis: Preparation of enantiomerically pure compounds
-
Esterhydrolases (Esterases, Lipases) are highly (chemo-, regio- and enantio-) selective biocatalysts for the transformation of racemic and achiral substrates into enantiomerically pure compounds.Numerous examples for their application in the preparation of synthetically useful chiral auxiliaries and building blocks for flavour compounds, pheromones and several pharmaceuticals including β-adrenergic blockers, antidepressants and ACE inhibitors are presented.
- Ader, U,Andersch, P,Berger, M,Goergens, U,Seemayer, R,Schneider, M
-
p. 145 - 150
(2007/10/02)
-
- An efficient route to enantiomerically pure antidepressants: Tomoxetine, nisoxetine and fluoxetine
-
Both enantiomers (R)- and (S)-3-chloro-1-phenyl-1-propanol can be obtained conveniently by an efficient enzymatic resolution process. They can be converted via enantioconvergent routes into all enantiomers of the important antidepressants (R)- and (S)-Tomoxetine, Fluoxetine and Nisoxetine.
- Schneider,Goergens
-
p. 525 - 528
(2007/10/02)
-
