- A METHOD FOR PREPARATION OF DIASTEREOMERIC LACTATE SALTS OF 1-(1-NAPHTHYL)ETHYL AMINE AND PURE ENANTIOMERS OF 1-(1-NAPHTHYL)ETHYL AMINE
-
The invention relates to method for preparation of pure enantiomers of 1-(1-naphthyl)ethyl amine by preparing lactate salt with chiral lactic acid as resolving agent. The method comprises reaction of L-lactic acid or D-lactic acid with racemic 1-(1-naphthyl)ethyl amine to form diastereomeric salts of (R/S)-1-(1-naphthyl)ethyl amine-(D/L)-lactate from which pure enantiomer is isolated. The invention also comprises method for preparation of compound with enriched enantiomers of 1-(1-naphthyl)ethyl amine from the mother liquor separated from the diastereomeric lactate salt. The enriched enantiomer is reacted with pure enantiomers of mandelic acid or lactic acid, preferably D-mandelic acid or L-mandelic acid and converted to diastereomeric mandelate salt. Pure (R)- or (S)-1-(1-naphthyl)ethyl amine is obtained from the diastereomeric mandelate salt. The chiral purity of pure enantiomer obtained is between 99% and 100%.
- -
-
Paragraph 0048
(2021/09/11)
-
- Asymmetric reduction method of nitrogen-phosphonyl protected imine
-
The invention discloses an asymmetric reduction method of nitrogen phosphonyl protective imine. The nitrogen phosphonyl protective imine is reduced into chiral amine in a hydrogen atmosphere under theaction of a metal catalyst and alkali, and the metal catalyst is prepared from a metal iridium complex and a nitrogen-phosphorus chiral ligand. The method provided by the invention has the characteristics of high enantioselectivity, high yield and high conversion number (TON). The method can be used for synthesizing various substituted chiral amines, can be used as an important intermediate for preparing various medicines, and has important significance for industrial production of medicines.
- -
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Paragraph 0180-0185
(2021/01/15)
-
- Enzymatic Primary Amination of Benzylic and Allylic C(sp3)-H Bonds
-
Aliphatic primary amines are prevalent in natural products, pharmaceuticals, and functional materials. While a plethora of processes are reported for their synthesis, methods that directly install a free amine group into C(sp3)-H bonds remain unprecedented. Here, we report a set of new-to-nature enzymes that catalyze the direct primary amination of C(sp3)-H bonds with excellent chemo-, regio-, and enantioselectivity, using a readily available hydroxylamine derivative as the nitrogen source. Directed evolution of genetically encoded cytochrome P411 enzymes (P450s whose Cys axial ligand to the heme iron has been replaced with Ser) generated variants that selectively functionalize benzylic and allylic C-H bonds, affording a broad scope of enantioenriched primary amines. This biocatalytic process is efficient and selective (up to 3930 TTN and 96percent ee), and can be performed on preparative scale.
- Jia, Zhi-Jun,Gao, Shilong,Arnold, Frances H.
-
supporting information
p. 10279 - 10283
(2020/07/27)
-
- Addition of Highly Polarized Organometallic Compounds to N-tert-Butanesulfinyl Imines in Deep Eutectic Solvents under Air: Preparation of Chiral Amines of Pharmaceutical Interest
-
Highly polarized organometallic compounds of s-block elements are added smoothly to chiral N-tert-butanesulfinyl imines in the biodegradable d-sorbitol/choline chloride eutectic mixture, thereby granting access to enantioenriched primary amines after quantitatively removing the sulfinyl group. The practicality of the method is further highlighted by proceeding at ambient temperature and under air, with very short reaction times (2 min), enabling the preparation of diastereoisomeric sulfinamides in very good yields (74–98 %) and with a broad substrate scope, and the possibility of scaling up the process. The method is demonstrated in the asymmetric syntheses of both the chiral amine side-chain of (R,R)-Formoterol (96 % ee) and the pharmaceutically relevant (R)-Cinacalcet (98 % ee).
- Capriati, Vito,Cicco, Luciana,García-álvarez, Joaquín,González-Sabín, Javier,Perna, Filippo M.,Ríos-Lombardía, Nicolás,Salomone, Antonio,Vitale, Paola
-
-
- Catalytic Reductions Without External Hydrogen Gas: Broad Scope Hydrogenations with Tetrahydroxydiboron and a Tertiary Amine
-
Facile reduction of aryl halides with a combination of 5% Pd/C, B2(OH)4, and 4-methylmorpholine is reported. Aryl bromides, iodides, and chlorides were efficiently reduced. Aryl dihalides containing two different halogen atoms underwent selective reduction: I over Br and Cl, and Br over Cl. Beyond these, aryl triflates were efficiently reduced. This combination was broadly general, effectuating reductions of benzylic halides and ethers, alkenes, alkynes, aldehydes, and azides, as well as for N-Cbz deprotection. A cyano group was unaffected, but a nitro group and a ketone underwent reduction to a low extent. When B2(OD)4 was used for aryl halide reduction, a significant amount of deuteriation occurred. However, H atom incorporation competed and increased in slower reactions. 4-Methylmorpholine was identified as a possible source of H atoms in this, but a combination of only 4-methylmorpholine and Pd/C did not result in reduction. Hydrogen gas has been observed to form with this reagent combination. Experiments aimed at understanding the chemistry led to the proposal of a plausible mechanism and to the identification of N,N-bis(methyl-d3)pyridin-4-amine (DMAP-d6) and B2(OD)4 as an effective combination for full aromatic deuteriation. (Figure presented.).
- Korvinson, Kirill A.,Akula, Hari K.,Malinchak, Casina T.,Sebastian, Dellamol,Wei, Wei,Khandaker, Tashrique A.,Andrzejewska, Magdalena R.,Zajc, Barbara,Lakshman, Mahesh K.
-
supporting information
p. 166 - 176
(2020/01/02)
-
- Enantioselective synthesis of (R)-Cinacalcet via cobalt-catalysed asymmetric Negishi cross-coupling
-
A novel enantioselective synthesis of (R)-cinacalcet with 99% enantiomeric excesses (ee) has been achieved. The main strategies of the approach include a gram-scale cobalt-catalysed asymmetric cross-coupling of racemic ester with arylzinc reagent, Hoffman-type rearrangement of acidamide, the amidation of chiral amine, and improving the ee of chiral amide from 87% to 99% via recrystallization.
- Sun, Xiao,Wang, Xueyang,Liu, Feipeng,Gao, Zidong,Bian, Qinghua,Wang, Min,Zhong, Jiangchun
-
p. 682 - 687
(2019/08/07)
-
- Method for asymmetrically synthesizing (R)-cinacalcet
-
The invention discloses a new method for asymmetrically synthesizing (R)-cinacalcet. The method includes: taking racemic 2-bromo-propionic acid (4-methoxybenzyl) ester as a starting raw material, andbeing in asymmetric Negishi cross coupling reaction with 2-nathphyl zinc bromide under catalysis of CoI2 and chiral ligand to generate (R)-2-(1-nathphyl) propionic acid (4-methoxybenzyl) ester; beingin reaction with oxalyl chloride through LiOH reduction to generate (R)-2-(1-nathphyl) propionyl chloride; being reaction with ammonia water to generate (R)-2-(1-nathphyl) propionamide, and allowing Hofmann degradation to obtain (R)-1-nathphalene ethylamine; being in reaction with 3-(trifluoromethyl) phenylpropionic acid to generate (R)-N-(1-nathphalene ethyl)-3-(3-trifluoromethylphenyl) propionamide, and allowing LiAlH4 reduction to obtain (R)-cinacalcet. Cobalt catalyzed asymmetric Negishi cross coupling reaction is utilized for the first time to build the chiral center of (R)-cinacalcet, the method is mild in reaction condition and environment-friendly, and optical purity of (R)-cinacalcet is high (99%ee).
- -
-
-
- Asymmetric Synthesis of Chiral Primary Amines by Ruthenium-Catalyzed Direct Reductive Amination of Alkyl Aryl Ketones with Ammonium Salts and Molecular H2
-
A ruthenium/C3-TunePhos catalytic system has been identified for highly efficient direct reductive amination of simple ketones. The strategy makes use of ammonium acetate as the amine source and H2 as the reductant and is a user-friendly and operatively simple access to industrially relevant primary amines. Excellent enantiocontrol (>90% ee for most cases) was achieved with a wide range of alkyl aryl ketones. The practicability of this methodology has been highlighted by scalable synthesis of key intermediates of three drug molecules. Moreover, an improved synthetic route to the optimal diphosphine ligand C3-TunePhos is also presented.
- Tan, Xuefeng,Gao, Shuang,Zeng, Weijun,Xin, Shan,Yin, Qin,Zhang, Xumu
-
supporting information
p. 2024 - 2027
(2018/02/19)
-
- Chemoenzymatic Approaches to the Synthesis of the Calcimimetic Agent Cinacalcet Employing Transaminases and Ketoreductases
-
Several chemoenzymatic routes have been explored for the preparation of cinacalcet, a calcimimetic agent. Transaminases (TAs) and ketoreductases (KREDs) turned out to be useful biocatalysts for the preparation of key optically active precursors. Thus, the asymmetric amination of 1-acetonaphthone yielded an enantiopure (R)-amine, which can be alkylated in one step to yield cinacalcet. Alternatively, the bioreduction of the same ketone resulted in an enantiopure (S)-alcohol, which was easily converted into the previous (R)-amine. In addition, the reduction was efficiently performed with the KRED and its cofactor co-immobilized on the same porous surface. This self-sufficient heterogeneous biocatalyst presented an accumulated total turnover number (TTN) for the cofactor of 675 after 5 consecutive operational cycles. Finally, in a preparative scale synthesis the TA-based approach was performed in aqueous medium and led to enantiopure cinacalcet in two steps and 50% overall yield. (Figure presented.).
- Marx, Lisa,Ríos-Lombardía, Nicolás,Farnberger, Judith F.,Kroutil, Wolfgang,Benítez-Mateos, Ana I.,López-Gallego, Fernando,Morís, Francisco,González-Sabín, Javier,Berglund, Per
-
p. 2157 - 2165
(2018/03/05)
-
- Preparation method of chiral amine compounds
-
The invention discloses a preparation method of chiral amine compounds. The preparation method of the chiral amine compounds specifically comprises the following steps: adding ketone compounds and chiral auxiliary (S)-a-phenylethylamine or (R)-a-phenylethylamine to an organic solvent to prepare an imine intermediate under the action of a large-steric-hindrance boron catalyst and a water removing agent; adding a reducing agent to the imine intermediate without separation and purification, and preparing the chiral amine compounds with a one-pot method. By calculation, the product yield is 81%-96%, and the highest de value can reach 99%. Compared with the prior art, the use amount of the large-steric-hindrance boron catalyst in the method can be reduced to 0.1 mol%, use of the equivalent metal catalyst is avoided from the source, and the method has the characteristics of being simple to operate, mild in reaction condition, wide in substrate applicability, environmental friendly and the like, and has better application value and potential economic and social benefits.
- -
-
-
- B(C6F5)3-Catalyzed Asymmetric Reductive Amination of Ketones with Ammonia Borane
-
The first example of metal-free B(C6F5)3-catalyzed asymmetric reduction amination of ketones with chiral α-methylbenzylamine (α-MBA) using ammonia borane as the reductant is reported. This one-pot method has a broad substrate scope and provides various chiral amines in 81-95% yield with 80-99% de. This protocol was further applied in the total synthesis of cinacalcet.
- Pan, Zhentao,Shen, Leixin,Song, Dingguo,Xie, Zhen,Ling, Fei,Zhong, Weihui
-
p. 11502 - 11509
(2018/09/25)
-
- A methof for preparing (R)- (+) - 1 - naphthalene of ethylamine
-
The invention discloses a splitting method for preparing (R)-(+)-1-naphthyl ethylamine, and belongs to the field of splitting of mixed levorotatory/dextrorotary compounds. In the provided method, (+)-4-phenyl-2-hydroxy-5,5-dimethyl-2-oxo-1,3,2-dioxaphosphorinane is taken as the main splitting agent and (+)-4-(2-chlorophenyl)-2-hydroxy-5,5-dimethyl-2-oxo-1,3,2-dioxaphosphorinane is taken as the auxiliary splitting agent so as to split mixed levorotatory/dextrorotary 1-naphthyl ethylamine, and finally (R)-(+)-1-naphthyl ethylamine and (S)-(+)-1-naphthyl ethylamine with a high optical purity can be obtained. The obtained (R)-(+)-1-naphthyl ethylamine has an optical purity as high as 99% e.e. or more. The provided method has the characteristics of high yield, recoverable splitting agent, simple operation, and suitability for industrial production.
- -
-
Paragraph 0040-0044; 0045-0049; 0050-0054; 0075-0078
(2017/08/25)
-
- A method for synthesizing [...]
-
The invention discloses a synthesis method of cinacalcet. The synthetic route is divided into two parts, namely, (1) preparing a chiral compound as shown in the description from racemic 1-naphthylethylamine as a starting material by virtue of a dynamic kinetic reliquid method in the presence of Pd/LDH-SA serving as a racemic catalyst, p-chlorophenol fatty acyl ester serving as an acyl donor and lipase serving as a biological reliquid catalyst; and (2) reacting m-trifluoromethylbenzaldehyde serving as a starting material and a cheap and easily available material acetaldehyde to obtain m-trifluoromethyl cinnamic aldehyde and carrying out reduced pressure distillation to obtain a pure product; reacting m-trifluoromethyl cinnamic aldehyde and the compound as shown in the description to produce an imine intermediate; dissolving the imine intermediate in ethanol and reacting in the presence of Raney nickel serving as a hydrogenation catalyst to obtain the product cinacalcet. By the synthesis method, the reaction yield and the optical purity of the product are increased, the reaction conditions are milder and the raw materials are easily available.
- -
-
Paragraph 0040
(2016/11/21)
-
- 6-TIPS-β-Cyclodextrin-Modified Fe3O4 for Facile Enantioseparation of 1-(1-Naphthyl)ethylamine
-
A new type of chiral magnetic nanoparticle was prepared from covalently linked magnetic nanoparticles (Fe3O4) and heptakis-(6-O-triisopropylsilyl)-β-cyclodextrin (6-TIPS-β-CD). The resulting selectors (TIPS-β-CD-MNPs) combined the good magnetic properties Fe3O4 and efficient chiral recognition ability of 6-TIPS-β-CD. The enantioselectivity of TIPS-β-CD-MNPs towards 1-(1-naphthyl)ethylamine was six times higher than that of the parent β-CD modified Fe3O4 particles.
- Wang, Lu,Liang, Xiang-Yong,Ding, Li-Sheng,Zhang, Sheng,Li, Bang-Jing
-
supporting information
p. 3513 - 3519
(2016/12/26)
-
- A split preparation of the optically pure R-1-naphtalenes process of ethylamine
-
The invention relates to a method for preparing optically-pure R-1-naphthylethylamine by splitting. The method comprises the following steps: introducing hydrogen into a high-pressure kettle filled with 1-naphthylethylamine serving as a raw material, Novozym435 serving as a splitting catalyst and D-(-)-O-acetyl mandelic acid serving as an acyl donor and KT-02 (nickel type catalyst) serving as a racemization catalyst for reacting, and fully transforming the 1-naphthylethylamine to obtain (R)-(1-(1-naphthyl)ethyl)acetamide (ee value is 99 percent); and purifying amide, performing acidolysis to obtain a R-1-naphthylethylamine salt, and performing the operation of alkalization, distillation, drying, concentration and the like on the R-1-naphthylethylamine salt to obtain the R-1-naphthylethylamine, wherein the product yield and the ee value in the whole steps can be over 90 percent. The method has the characteristics of adoption of cheap and readily-available racemization catalyst, complete utilization of the raw material, high product yield and the like. The method has extremely high guidance and application values in the production and preparation of the R-1-naphthylethylamine.
- -
-
Paragraph 0009-0012
(2017/04/08)
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- PROCESS FOR THE PREPARATION OF CHIRAL AMINES FROM PROCHIRAL KETONES
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There is provided a method for the preparation of an enantiomerically enriched amine from a prochiral ketone.
- -
-
Page/Page column 5; 6
(2015/12/11)
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- AN IMPROVED PROCESS FOR PREPARATION OF N-[1-(1-NAPHTHYL)ETHYL] -3- [3-(TRIFLUOROMETHYL)PHENYL]PROPAN-1-AMINE AND PHARMACEUTICALLY ACCEPTABLE SALTS THEREOF
-
The present invention relates to an improved process for preparation of N- [1-(1-naphthyl)ethyl]-3-[3-(trifluoromethyl)phenyl]propan-1-amine and pharmaceutically acceptable salts thereof. In particular, the present invention relates to an improved process for preparation cinacalcet or pharmaceutically acceptable salts and intermediates thereof.
- -
-
-
- Kinetic resolution of primary amines via enantioselective N-acylation with acyl chlorides in the presence of supramolecular cyclodextrin nanocapsules
-
The non-enzymatic kinetic resolution of primary amines via enantioselective N-acylation with acyl chlorides was accomplished for the first time by using the selective sequestration of one enantiomer within a supramolecular cyclodextrin (CD) nanocapsule in nonpolar solvents. In addition, the first example of a crystalline structure for an inclusion complex between an acyl chloride and a CD derivative is reported.
- Asahara, Haruyasu,Kida, Toshiyuki,Iwamoto, Takuya,Hinoue, Tomoaki,Akashi, Mitsuru
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p. 197 - 203
(2014/01/06)
-
- Enantioselective synthesis of (R)-2-arylpropanenitriles catalysed by ene-reductases in aqueous media and in biphasic ionic liquid-water systems
-
The enantioselective reduction of α-methylene nitrile derivatives catalysed by ene-reductases affords the corresponding (R)-2-arylpropanenitriles with high conversion values. The reaction is investigated either in aqueous medium (with an organic cosolvent or by loading the substrate onto hydrophobic resins) or in a biphasic ionic liquid-water system. The use of ionic liquids, herein with isolated ene-reductases, is found to improve the work-up and the substrate recovery method. The synthetic manipulation of the final chiral nitrile derivatives indicates how this biocatalysed method can be exploited for the preparation of a wide range of chiral compounds.
- Brenna, Elisabetta,Crotti, Michele,Gatti, Francesco G.,Manfredi, Alessia,Monti, Daniela,Parmeggiani, Fabio,Santangelo, Sara,Zampieri, Davila
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p. 2425 - 2431
(2014/08/18)
-
- Asymmetric synthesis of nonracemic primary amines via spiroborate-catalyzed reduction of pure (E)- and (Z)-O-benzyloximes: Applications toward the synthesis of calcimimetic agents
-
Highly enantiopure (1-aryl)- and (1-naphthyl)-1-ethylamines were synthesized by the borane-mediated reduction of single-isomeric (E)- and (Z)-O-benzyloxime ethers using the stable spiroborate ester derived from (S)-diphenyl valinol and ethylene glycol as the chiral catalyst. Primary (R)-arylethylamines were prepared by the reduction of pure (Z)-ethanone oxime ethers in up to 99% ee using 15% of catalyst. Two convenient and facile approaches to the synthesis of new and known calcimimetic analogues employing enantiopure (1-naphthalen-1-yl)ethylamine as chiral precursor are described.
- Ou, Wenhua,Espinosa, Sandraliz,Meléndez, Héctor J.,Farré, Silvia M.,Alvarez, Jaime L.,Torres, Valerie,Martínez, Ileanne,Santiago, Kiara M.,Ortiz-Marciales, Margarita
-
p. 5314 - 5327
(2013/07/25)
-
- A versatile Ru catalyst for the asymmetric transfer hydrogenation of both aromatic and aliphatic sulfinylimines
-
A highly efficient Ru catalyst based on an achiral, very simple, and inexpensive amino alcohol ligand (2-amino-2-methylpropan-1-ol) has been developed for the asymmetric transfer hydrogenation (ATH) of chiral N-(tert-butylsulfinyl)imines. This complex is able to catalyze the ATH of both aromatic and the most challenging aliphatic sulfinylimines by using isopropyl alcohol as the hydrogen source. The diastereoselective reduction of aromatic, heteroaromatic, and aliphatic sulfinylketimines, including sterically congested cases, over short reaction times (1-4 h), followed by desulfinylation of the nitrogen atom, affords the corresponding highly enantiomerically enriched (ee up to >99%) α-branched primary amines in excellent yields. The same ligand was equally effective for the synthesis of both (R)- and (S)-amines by using the appropriate absolute configuration in the iminic substrate. DFT mechanistic studies show that the hydrogen-transfer process is stepwise. Moreover, the origin of the diastereoselectivity has been rationalized.
- Pablo, Oscar,Guijarro, David,Kovacs, Gabor,Lledos, Agusti,Ujaque, Gregori,Yus, Miguel
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p. 1969 - 1983
(2012/03/26)
-
- Microwave-assisted deacylation of unactivated amides using ammonium-salt-accelerated transamidation
-
Easy does it! The chemoselective oxidative ?-C(sp3)H alkylation/cyclization reaction of N-benzyl carbamates using simple mono-, di-, and trisubstituted olefins provides functionalized N-heterocycles such as oxazinones (see picture). A TEMPO oxoammonium salt serves as the oxidant, making it possible to carry out the reaction at low temperatures. Neither a metal catalyst nor preactivation in the ?-position to the nitrogen group are needed.
- Shimizu, Yuhei,Morimoto, Hiroyuki,Zhang, Ming,Ohshima, Takashi
-
supporting information; experimental part
p. 8564 - 8567
(2012/09/11)
-
- N-octanoyldimethylglycine trifluoroethyl ester, an acyl donor leading to highly enantioselective protease-catalysed kinetic resolution of amines
-
The use of N-octanoyldimethylglycine trifluoroethyl ester as acyl donor in the kinetic resolution of aliphatic amines catalysed by proteases led to enantiomeric ratios >200 in most cases. The resolutions mediated by Protex 6L were shown to be much faster
- Queyroy, Severine,Vanthuyne, Nicolas,Gastaldi, Stephane,Bertrand, Michele P.,Gil, Gerard
-
supporting information; experimental part
p. 1759 - 1764
(2012/08/08)
-
- Efficient synthesis and practical resolution of 1-(naphthalen-1-yl) ethanamine, a key intermediate for cinacalcet
-
An efficient synthesis of 1-(naphthalen-1-yl)ethanamine (RS-2) and its practical resolution to optically pure (1R)-(naphthalen-1-yl)ethanamine (R-(+)-2), a key intermediate in the synthesis of cinacalcet hydrochloride (1), is described. The resolution of RS-2 using R-(-)-mandelic acid as a resolving agent in ethanol was established on an industrial scale to give pure R-(+)-2 with >99.8% ee after liberation of the amine from its mandelate salt. An efficient process for the racemization of undesired isomer S-(-)-2 is also provided to maximize the yield of desired enantiomer.
- Mathad, Vijayavitthal T.,Shinde, Gorakshanath B.,Ippar, Sharad S.,Niphade, Navnath C.,Panchangam, Raghavendra K.,Vankawala, Pravinchandra J.
-
p. 341 - 346
(2011/04/15)
-
- Enantiopure cyclic O-substituted phenylphosphonothioic acid: Synthesis and chirality-recognition ability
-
As a new acidic selector (resolving agent), we synthesized an enantiopure O-alkyl phenylphosphonothioic acid with a seven-membered ring ((R)-5), which was designed on the basis of the results for the enantioseparation of 1-arylethylamine derivatives with acyclic O-ethyl phenylphosphonothioic acid (I). The phosphonothioic acid (R)-5 showed unique chirality-recognition ability in the enantioseparation of 1-naphthylethylamine derivatives, aliphatic secondary amines, and amino alcohols; the ability was complementary to that of I. The X-ray crystallographic analyses of the less- and more-soluble diastereomeric salts showed that hydrogen-bonding networks in the salt crystals are 21-column-type with a single exception which is cluster-type. In the cases of the 21-column-type crystals, stability of the crystals is firstly governed by hydrogen bonds to form a 21-column and secondly determined by intra-columnar T-shaped CH/π interaction(s), intra-columnar hydrogen bond(s), inter-columnar van der Waals interaction and/or inter-columnar T-shaped CH/π interaction(s). In contrast, the cluster-type salt crystal is stabilized by the assistance of inter-cluster T-shaped CH/π and van der Waals interactions. To realize still more numbers of intra- and inter-columnar and -cluster T-shaped CH/π interactions, the seven-membered ring of (R)-5 plays a considerable role. Copyright
- Ribeiro, Nigel,Kobayashi, Yuka,Maeda, Jin,Saigo, Kazuhiko
-
experimental part
p. 438 - 448
(2012/01/02)
-
- COMPOSITIONS AND METHODS FOR CYCLOFRUCTANS AS SEPARATION AGENTS
-
The present invention relates to derivatized cyclofructan compounds, compositions comprising derivatized cyclofructan compounds, and methods of using compositions comprising derivatized cyclofructan compounds for chromatographic separations of chemical species, including enantiomers. Said compositions may comprise a solid support and/or polymers comprising derivatized cyclofructan compounds.
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-
Page/Page column 45-49; 61
(2010/12/31)
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- Separation of the phenoxy acid herbicides and their enantiomers by capillary zone electrophoresis in presence of highly sulphated cyclodextrins
-
The study of the chiral compounds and their fate in the environment is receiving an increasing attention - enantiomeric ratios are being measured and enantioselective degradation processes are being reported. It is particularly important with the toxic compounds like the pesticides, which are being freely used in the environment to control the harmful pests. Capillary zone electrophoresis was used for the chiral and mutual separation of four phenoxy acid herbicides using highly sulphated cyclodextrins (HSCD) in the buffer. The CE runs were performed with reverse polarity (anode in the outlet vial) using the acidic ammonium formate buffer (20 mmol, pH 3). Under these conditions of suppressed the electroendoosmotic flow (EOF), the analytes are mobilized to the anode by entering into host guest relation with the migrating negatively charged sulphated cyclodextrin. The phenoxy acid herbicides selected for the purpose were fenoprop, dicloprop, mecoprop and 2,4-DB. The α-HSCD and β-HSCD have been tested as resolving agents in the CE for the separation of the enantiomers of the herbicides. Though the chiral separation of the dicloprop and mecoprop were achieved with α-HSCD but it was not able to resolve fenoprop. With β-HSCD the required base line separation was achieved. Potential difference selected was 10 kV. The limit of detection (S/N=3) achieved in present case is 0.15 ppm for fenoprop, 0.14 ppm for dicloprop and mecoprop and 0.11 ppm for 2,4-DB.
- Malik, Ashok Kumar,Aulakh, Jatinder Singh,Fekete, Agnes,Philippe, Schmitt-Kopplin
-
experimental part
p. 1163 - 1167
(2010/08/20)
-
- Efficient kinetic resolution of racemic amines using a transaminase in combination with an amino acid oxidase
-
A range of enantiomerically pure (R)- and (S)-configured chiral amines has been prepared in excellent e.e. (99%) by combining a transaminase enzyme with an amino acid oxidase and catalytic quantities of pyruvate.
- Truppo, Matthew D.,Turner, Nicholas J.,Rozzell, J. David
-
supporting information; experimental part
p. 2127 - 2129
(2009/09/06)
-
- N-Acyl glycinates as acyl donors in serine protease-catalyzed kinetic resolution of amines. Improvement of selectivity and reaction rate
-
Enzymatic kinetic resolution of aliphatic and benzylic amines leading to (S)-amides was achieved by using alkaline protease as the catalyst and N-octanoyl glycine trifluoroethyl ester as the acyl donor; enantioselectivity ranged between 4 to 244, while reaction times were dramatically shortened and ranged between 15 min to 6 h. The 2008 Royal Society of Chemistry.
- Nechab, Malek,El Blidi, Lahssen,Vanthuyne, Nicolas,Gastaldi, Stephane,Bertrand, Michele P.,Gil, Gerard
-
supporting information; scheme or table
p. 3917 - 3920
(2009/06/28)
-
- Studies on the bisoxazoline- and (-)-sparteine-mediated enantioselective addition of organolithium reagents to imines
-
The enantioselective addition of organolithium reagents to N-anisylaldimines promoted by chiral bisoxazolines and (-)-sparteine as external ligands is described. This reaction proceeds readily with a wide range of aldimine substrates (aliphatic, aromatic, olefinic) and organolithium nucleophiles (Me, n-Bu, Ph, vinyl) in excellent yields (81-99%) and with high enantioselectivities (up to 97:3.0 er). The external ligands can be used in substoichiometric amounts albeit with slightly attenuated enantioselectivities. A systematic evaluation of the structural features of the bisoxazolines revealed a primary contribution from the substituent at C(4) and a secondary influence from the bridging substituents. A computational analysis (PM3) provided a clear rationalization for the origin of enantioselectivity.
- Denmark, Scott E.,Nakajima, Noriyuki,Stiff, Cory M.,Nicaise, Olivier J.-C.,Kranz, Michael
-
supporting information; experimental part
p. 1023 - 1045
(2009/05/30)
-
- PROCESSES FOR THE PREPARATION OF CINACALCET
-
There are described several processes for making a free base of cinacalcet. One of the described processes goes through an intermediate of the formula (II) where R1 and R2 are both hydrogen, or R1 and R2, together, form a double bond.
- -
-
Page/Page column 24-25
(2008/12/05)
-
- Nonenzymatic kinetic resolution of amines in ionic liquids
-
Ionic liquids are remarkably suitable and clean media for performing nonenzymatic kinetic resolution (KR) of amines through enantioselective N-acetylation: high levels of selectivity were obtained with a large variety of amines at room temperature (up to s = 30). Georg Thieme Verlag Stuttgart.
- Sabot, Cyrille,Subhash, Pithani V.,Valleix, Alain,Arseniyadis, Stellios,Mioskowski, Charles
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p. 268 - 272
(2008/09/21)
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- Palladium catalysts on alkaline-earth supports for racemization and dynamic kinetic resolution of benzylic amines
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Palladium catalysts on alka-line-earth supports were studied as new heterogeneous catalysts for racemization of chiral benzylic amines such as 1-phenylethylamine. Particularly 5% Pd/BaSO4 and 5% Pd/CaCO 3 were able to selectively racemize amines, with minimal formation of secondary amines or hydrogenolysis to ethylbenzene. In contrast, these side reactions were pronounced on Pd/C. A reaction mechanism is proposed that is consistent with the reaction kinetics. The catalyst activity was found to depend on the number of available surface Pd atoms, determined by titration with CO. The selectivity crucially depends on the rate of condensation of the amine and the primary imine. which is highest on Pd/C. The racemization catalysts were combined in one pot with an immobilized lipase to perform dynamic kinetic resolution of chiral amines. High yields (up to 88%) of essentially enantiopure amides were obtained in a single step. The chemo-enzymatic catalyst system proved to be stable and could be reused without losing the initial activity.
- Parvulescu, Andrei N.,Jacobs, Pierre A.,De Vos, Dirk E.
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p. 2034 - 2043
(2008/02/03)
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- Amidation of amines with esters catalyzed by Candida antarctica lipase (CAL)
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Candida antarctica lipase (CAL) is used to convert amines and esters into amides, especially as a chiral resoluting catalyst for the enantioselective amidation of racemic esters or racemic amines in an effort to demonstrate the ability of lipase to differentiate between enantiomeric substrates. It is a very useful synthetic method for amides. The effects of substrate modification on the yield and enantiomeric excess (ee) are studied. The R-enantiomer will react faster for racemic mixture of amine in which the amino group attaches directly to the chiral carbon, and the same for racemic mixture of ester in which the carbonyl group attaches directly to the chiral carbon. The enantioselectivity of CAL is complicated for the amidation of racemic mixture of amine with racemic mixture of ester.
- Yang, Bo,Zhang, Yanjun,Zhang, Shusheng,Izumi
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p. 1312 - 1316
(2007/10/03)
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- Kinetic resolution of amines: A highly enantioselective and chemoselective acetylating agent with a unique solvent-induced reversal of stereoselectivity
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Solvents lend a hand: Changing the polarity of the reaction solvent from 1,3-dimethyltetrahydropyrimidin-2-one (DMPU) to toluene reverses the stereo-selectivity observed in the acetylation of amines with (1S,2S)-1 (see scheme). Optimizing the reaction conditions led to an unprecedented 90% ee (S) in DMPU at -20°C with a 33% conversion.
- Arseniyadis, Stellios,Valleix, Alain,Wagner, Alain,Mioskowski, Charles
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p. 3314 - 3317
(2007/10/03)
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- Highly Enantioselective Hydrogen-Transfer Reductive Amination: Catalytic Asymmetric Synthesis of Primary Amines
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Ammonium formate is the hydrogen source in the catalytic asymmetric reductive amination of ketones presented here (Leuckart-Wallach-type reaction). The reaction proceeds smoothly in methanol in the presence of Ir, Rh, and Ru catalysts. Primary amines were obtained as products in good yields with high enantioselectivities after hydrolytic workup when [((R)-tol-binap) RuCl 2] was used as the catalyst (see scheme). R1, R 2=alkyl, aryl.
- Kadyrov, Renat,Riermeier, Thomas H.
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p. 5472 - 5474
(2007/10/03)
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- Enzymatic resolution of bicyclic 1-heteroarylamines using Candida antarctica lipase B
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Candida antarctica lipase B has been used to kinetically resolve a structurally diverse series of bicyclic 1-heteroaryl primary amines by enantioselective acetylation. High yields of either enantiomer could be obtained with excellent enantioselectivity (90-99% ee), while the undesired enantiomer could, in some cases, be recycled by thermal racemization. The absolute stereochemistry of the products was confirmed by an X-ray crystal structure.
- Skupinska, Krystyna A.,McEachern, Ernest J.,Baird, Ian R.,Skerlj, Renato T.,Bridger, Gary J.
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p. 3546 - 3551
(2007/10/03)
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- Highly efficient resolutions with isopropylidene glycerol 3-carboxy-2-naphthoate
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A number of chiral 1-arylethylamines and 1-alkylethylamines were resolved with the 3-carboxy-2-naphthoate of isopropylidene glycerol 2, previously reported to be an even more efficient resolving agent for 1-phenylethylamine than the corresponding hemiphthalate 1. The results obtained for the 1-arylethylamines confirm such a trend, revealing impressive resolution ability, in particular, for 1-(4-bromophenyl)-, 1-(4-nitrophenyl)- and 1-(2-naphthyl)ethylamine, whose enantiomers were almost quantitatively separated with (S)-2 by a single precipitation of the less soluble (S,S) diastereomeric salt. Additionally, the success of the resolutions of 1-alkylethylamines (1-phenyl-2-propylamine, 1-cyclohexylethylamine and 2-butylamine), which could not be resolved with 1, indicates that the novel carboxy ester 2 has a wider range of application than 1.
- Pallavicini, Marco,Bolchi, Cristiano,Fumagalli, Laura,Valoti, Ermanno,Villa, Luigi
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p. 2277 - 2282
(2007/10/03)
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- Catalytic asymmetric hydroboration/amination and alkylamination with rhodium complexes of 1,1′-(2-diarylphosphino-1-naphthyl)isoquinoline
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Catecholboronate esters formed by asymmetric hydroboration of arylalkenes are not directly converted to amines by reaction with hydroxylamine-O-sulfonic acid. Prior conversion to a trialkylborane by reaction with ZnEt2 or MeMgCl permits a subsequent amination reaction to occur with essentially complete retention of configuration, leading to a range of primary α-arylalkylamines in up to 97% enantiomeric excess (ee). Secondary, but not tertiary amines may be formed by a related pathway when in situ generated alkylchloramines are employed as the aminating agent. The catalytic asymmetric hydroboration, β-alkylation and amination steps may be combined in a single stage. Overall, this provides a practical procedure for the synthesis of enantiomerically enriched arylamines, exemplified inter alia by the synthesis of (S)-1,2,3,4-tetrahydro-1-naphthylamine in 95-97% ee and of (R)-N-(cyclohexyl)-1′-(4-methoxyphenyl)ethylamine in 93 % ee.
- Fernandez, Elena,Maeda, Kenji,Hooper, Mark W.,Brown, John M.
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p. 1840 - 1846
(2007/10/03)
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- A high-performance, tailor-made resolving agent: Remarkable enhancement of resolution ability by introducing a naphthyl group into the fundamental skeleton1
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A novel resolving agent, 2-naphthylglycolic acid (2-NGA), was designed for p-substituted 1-arylethylamines on the basis of the consideration that a rigid and large naphthyl group would be favorable for the close packing of supramolecular hydrogen-bond sheets formed between the carboxy groups of 2-NGA and the amino groups of p-substituted 1-arylethylamines. Racemic 2-NGA was readily available from commercially available raw materials, and both enantiopure forms could be obtained by simple diastereomeric resolution with enantiopure 1-phenyl-ethylamine. Thus-prepared enantiopure 2-NGA was found to have an excellent resolution ability not only for p-substituted 1-arylethylamines, but also for a wide variety of chiral primary amines. X-Ray crystallographic analyses of the less- and more-soluble diastereomeric salts revealed that this excellent resolution ability of 2-NGA arose from the formation of a supramolecular hydrogen-bond sheet with the primary amine, as we had expected, and also from the possible achievement of an infinite chain of CH... π interaction between its naphthyl group and the aromatic group of the amine, which was formed in the hydrophobic region of the supramolecular hydrogen-bond sheet.
- Kinbara, Kazushi,Harada, Yoshiko,Saigo, Kazuhiko
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p. 1339 - 1347
(2007/10/03)
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- Enantioselective electrocatalytic oxidation of racemic amines using a chiral 1-azaspiro[5.5]undecane N-oxyl radical
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A preparative electrocatalytic oxidation of racemic amines, which contain a chiral centre α to the amino group, on (6S, 7R, 10R)-4-acetylamino-2,2,7-trimethyl-10-isopropyl-1-aza-spiro[5.5]undecane N-oxyl yielded mixtures of carbonyl compounds (54.3-66.1%) and amines (33.9-45.7%) after 5 h of electrolysis, in which the current efficiency, turnover number, enantiopurity of the remaining (R)-isomers and S values were 90.7-94.8%, 21.7-26.5, 62-78% and 4.7-5.8, respectively.
- Kashiwagi, Yoshitomo,Kurashima, Futoshi,Kikuchi, Chikara,Anzai, Jun-Ichi,Osa, Tetsuo,Bobbitt, James M.
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p. 1983 - 1984
(2007/10/03)
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- Cross-linked crystals of subtilisin: Versatile catalyst for organic synthesis
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Cross-linked enzyme crystals (CLECs) of subtilisin exhibit excellent activity in aqueous and various organic solvents. This catalyst is more stable than the native enzyme in both aqueous and mixed aqueous/organic solutions. Subtilisin-CLEC was shown to be a versatile catalyst. It was used for the syntheses of peptides and peptidomimetics, mild hydrolysis of amino acid and peptide amides, enantio- and regioselective reactions, and transesterifications.
- Wang, Yi-Fong,Yakovlevsky, Kirill,Zhang, Bailing,Margolin, Alexey L.
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p. 3488 - 3495
(2007/10/03)
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- Saponification agents. 2. Synthesis of arylisocyanates with ethyl lactate and their use in racemic bases saponification
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Reaction of the arylisocyanates 2a-c with ethyl (S)-(-)-lactate, followed by careful saponification, afforded the corresponding chiral acids (S)-(-)- 4a-c. The latter were successfully used for the resolution of various racemic bases belonging to both the ephedrine and α-aryl ethylamine series.
- Brown,Moudachirou
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p. 10309 - 10320
(2007/10/02)
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- Asymmetric Supported Reactions: Synthesis Of Chiral Amines
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Deracemization of amines, linked via Schiff bases to a chiral polyacrylic polymer has been studied.An enantiomeric excess of 72percent has been obtained with α-methyl benzylamine.
- Calmes, Monique,Daunis, Jacques,Hanouneh, Ahmad,Jacquier, Robert
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p. 817 - 820
(2007/10/02)
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- Ethyl (1R,6S)-2,2,6-trimethylcyclohexanecarboxylate, aroma chemical composition containing the same and process of producing the same
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Ethyl (1R,6S)-2,2,6-trimethylcyclohexanecarboxylate represented by formula (1) STR1 is disclosed. Also, an aroma chemical composition containing the same and a process of the production of the same are disclosed.
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- 1,2- vs 1,4-Addition of Nucleophilic Organometallics to Nonracemic 2-(1-Naphthyl)- and 2-Cinnamyl-1,3-oxazolidines
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We herein report our results where the addition of organomagnesium reagents to 2-(1-naphthyl)- and 2-cinnamyl-1,3-oxazolidines occurred consistently in a 1,4-conjugate manner, while lithium, cerium and copper organometallic reagents added in a 1,2 fashion.The 1,4-conjugate addition pathway was primarely exploited by using (4R)-2-(1-naphthyl)-4-phenyl-1,3-oxazolidine (4) as a substrate to obtain, after NaBH4 reduction of the intermediate aldehyde, trans-disubstituted 1,2-dihydronaphthalenes with enantiomeric excess of 93-94percent.The amino alcohol products resulting from1,2-addition were oxidatively cleaved to afford enantiomeric enriched (R)-α-(1-naphthyl)alkylamines 6a and 6b in 99percent ee.
- Pridgen, Lendon N.,Mokhallalati, Mohamed K.,Wu, Ming-Jung
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p. 1237 - 1241
(2007/10/02)
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- Acyclic Stereoselection in the Alkylation of Chiral Dipole-Stabilized Organolithiums: A Self-Immolative Chirality Transfer Process for the Synthesis of Primary Amines
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A comparison of 1,3- and 1,5-asymmetric induction shows the former to have far greater selectivity in the methylation of chiral dipole-stabilized organolithiums.The asymmetric alkylation of N-benzyloxazolidinones is employed as the key step in a new synthesis of primary amines by asymmetric alkylation α to nitrogen.
- Gawley, Robert E.,Rein, Kathleen,Chemburkar, Sanjay
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p. 3002 - 3004
(2007/10/02)
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- Asymmetric Synthesis Using Chirally Modified Borohydrides. Part 3. Enantioselective Reduction of Ketones and Oxime Ethers with Reagents Prepared from Borane and Chiral Amino Alcohols
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The asymmetric reduction of aromatic and aliphatic ketones, halogeno ketones, keto esters, and ketone oxime ethers with reagents prepared from borane and chiral amino alcohols has been investigated.When α,α-diphenyl-β-amino alcohols, such as (2S,3R)-(-)-2-amino-3-methyl-1,1-diphenylpentanol (2d), were used as a chiral auxiliary, very high enantioselectivities (ca. 90percent e.e.) were obtained in the reduction of various ketones and oxime ethers.
- Itsuno, Shinichi,Nakano, Michio,Miyazaki, Koji,Masuda, Hirofumi,Ito, Koichi,et al.
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p. 2039 - 2044
(2007/10/02)
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- OPTICALLY ACTIVE F-2-ISOPROPOXYPROPIONIC ACID: A NOVEL DERIVATIZING AGENT FOR GAS CHROMATOGRAPHIC ANALYSIS
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F-2-Isopropoxypropionic acid (PIPA) was resolved into enantiomers via its diastereomeric (+)-1-phenylethylamide. (+)-F-2-Isopropoxypropionyl derivatives of several chiral 1-arylalkylamines and α-amino acids were effectively resolved by gas chromatography at low temperature.
- Kawa, Hajimu,Yamaguchi, Fumihiko,Ishikawa, Nobuo
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p. 745 - 748
(2007/10/02)
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