- Highly Efficient and Robust Enantioselective Liquid–Liquid Extraction of 1,2-Amino Alcohols utilizing VAPOL- and VANOL-based Phosphoric Acid Hosts
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The large-scale production of enantiopure compounds in a cost-effective and environmentally friendly manner remains one of the major challenges of modern-day chemistry. The resolution of racemates through enantioselective liquid–liquid extraction was developed as a suitable solution but has remained largely underused, owing to a lack of highly efficient and robust chiral hosts to mediate the process. This paucity of hosts can in part be attributed to a poor understanding of the underlying principles behind these processes hindering the design of more efficient selectors. A previously untested class of hosts, VAPOL and VANOL derived phosphoric acids, has been studied in depth for the efficient enantioselective liquid–liquid extraction of 1,2-amino alcohols. A systematic investigation of extraction parameters was conducted, revealing many key interactions and DFT calculations illustrate the binding modes for the 1:1 complexes that are involved in chiral recognition. The resulting, now-optimized, procedures are highly robust and easy to implement. They are also easily scalable, as demonstrated by U-tube experiments.
- Pinxterhuis, Erik B.,Gualtierotti, Jean-Baptiste,Wezenberg, Sander J.,de Vries, Johannes G.,Feringa, Ben L.
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p. 178 - 184
(2017/12/15)
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- Highly efficient enantioselective liquid-liquid extraction of 1,2-amino-alcohols using SPINOL based phosphoric acid hosts
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Access to enantiopure compounds on large scale in an environmentally friendly and cost-efficient manner remains one of the greatest challenges in chemistry. Resolution of racemates using enantioselective liquid-liquid extraction has great potential to meet that challenge. However, a relatively feeble understanding of the chemical principles and physical properties behind this technique has hampered the development of hosts possessing sufficient resolving power for their application to large scale processes. Herein we present, employing the previously untested SPINOL based phosphoric acids host family, an in depths study of the parameters affecting the efficiency of the resolution of amino-alcohols in the optic of further understanding the core principles behind ELLE. We have systematically investigated the dependencies of the enantioselection by parameters such as the choice of solvent, the temperature, as well as the pH and bring to light many previously unsuspected and highly intriguing interactions. Furthermore, utilizing these new insights to our advantage, we developed novel, highly efficient, extraction and resolving protocols which provide remarkable levels of enantioselectivity. It was shown that the extraction is catalytic in host by demonstrating transport in a U-tube and finally it was demonstrated how the solvent dependency could be exploited in an unprecedented triphasic resolution system.
- Pinxterhuis, Erik B.,Gualtierotti, Jean-Baptiste,Heeres, Hero J.,De Vries, Johannes G.,Feringa, Ben L.
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p. 6409 - 6418
(2017/08/29)
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- A method for synthesizing the chiral anti-form yinyin amine is mellow (by machine translation)
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The invention discloses a method for synthesizing the chiral anti-form yinyin amine is mellow. by yin as raw materials, the sodium tungstate/phase transfer catalyst/hydrogen peroxide system to reaction ring oxidation, then reaction with benzylamine, split through the mandelic acid, hydrogenated to obtain ≥ 98% ee the anti-form yinyin amine is mellow. The method uses and is simple, easy to operate, compared to the previous resolution method, more easy to realize the amplifying production. (by machine translation)
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- 3,3′-diaryl-BINOL phosphoric acids as enantioselective extractants of benzylic primary amines
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We report that 3,3′-diaryl-BINOL phosphoric acids are effective enantioselective extractants in chiral separation methods based on reactive liquid-liquid extraction. These new extractants are capable of separating racemic benzylic primary amine substrates. The effect of the nature of the substituents at the 3,3′-positions of the host were examined as well as the structure of the substrate, together with important parameters such as the organic solvent, the pH of the aqueous phase, and the host stoichiometry. Titration of the substrate with the host was monitored by FTIR, NMR, UV-Vis, and CD spectroscopy, which provided insight into the structure of the host-guest complex involved in extraction.
- Verkuijl, Bastiaan J.V.,De Vries, Johannes G.,Feringa, Ben L.
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experimental part
p. 34 - 43
(2011/10/08)
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- Cyclic trans-β-amino alcohols: Preparation and enzymatic kinetic resolution
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Enantioenriched cyclic β-amino alcohols, trans-2-aminocyclohexanols (ee, >99%), trans-2-aminocyclopentanols (ee, >99%), trans-1-amino-2- indanols (ee, >99%) and trans-2-amino-1-indanols (ee, ~98%) were prepared in high yields via an Arthrobacter sp. Lipase/PLAP catalyzed kinetic resolution of racemic phthalimido acetates. The addition of toluene as a co-solvent dramatically improved the hydrolysis and enantioselectivity, whereas for indanols, substrate immobilization on Celite improved the efficacy of the kinetic resolution.
- Rouf, Abdul,Gupta, Pankaj,Aga, Mushtaq A.,Kumar, Brijesh,Parshad, Rajinder,Taneja, Subhash C.
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scheme or table
p. 2134 - 2143
(2012/05/04)
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- COMPOSITIONS AND METHODS FOR CYCLOFRUCTANS AS SEPARATION AGENTS
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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; 53
(2010/12/31)
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- Development of new HPLC chiral stationary phases based on native and derivatized cyclofructans
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An unusual class of chiral selectors, cyclofructans, is introduced for the first time as bonded chiral stationary phases. Compared to native cyclofructans (CFs), which have rather limited capabilities as chiral selectors, aliphatic-and aromatic-functionalized CF6s possess unique and very different enantiomeric selectivities. Indeed, they are shown to separate a very broad range of racemic compounds. In particular, aliphatic-derivatized CF6s with a low substitution degree baseline separate all tested chiral primary amines. It appears that partial derivatization on the CF6 molecule disrupts the molecular internal hydrogen bonding, thereby making the core of the molecule more accessible. In contrast, highly aromaticfunctionalized CF6 stationary phases lose most of the enantioselective capabilities toward primary amines, however they gain broad selectivity for most other types of analytes. This class of stationary phases also demonstrates high "loadability" and therefore has great potential for preparative separations. The variations in enantiomeric selectivity often can be correlated with distinct structural features of the selector. The separations occur predominantly in the presence of organic solvents.
- Sun, Ping,Wang, Chunlei,Breitbach, Zachary S.,Zhang, Ying,Armstrong, Daniel W.
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experimental part
p. 10215 - 10226
(2010/05/01)
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- Exploring structural diversity in ligand design: The aminoindanol case
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A series of enantiopure ligands based on the aminoindanol scaffold, but differing in regio-and stereochemistry has been synthesized. These ligands have been conveniently derivatized and their catalytic efficiency in different enantioselective reactions has been screened to determine privileged candidates with respect to regio- and stereochemistry for each considered process. The nature of the amino substituent has been optimized for specific applications and this has led to the development of an efficient method for the preparation of bulky bicyclic amines by reductive amination.
- Rodriguez-Escrich, Sergi,Sola, Lluis,Jimeno, Ciril,Rodriguez-Escrich, Carles,Pericas, Miquel A.
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supporting information; experimental part
p. 2250 - 2260
(2009/10/06)
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- PREPARATION OF IMIDAZOLE DERIVATIVES AND METHODS OF USE
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This invention relates to imidazole compounds which are useful in promoting smoking cessation and maintaining abstinence.
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Page/Page column 50
(2010/02/14)
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- Convenient and inexpensive synthesis of (1R,2R)-trans-1-amino-6-nitroindan- 2-ol
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Racemic trans-1-amino-6-nitroindam-2-ol (rac-1) has been prepared in five steps from inexpensive indene (7) in 96% overall yield. The key step was a direct nitration of the known trans-1-aminoindan-2-ol (rac-9) which gave sulfuric acid mono-(rac-trans-1-amino-6-nitroindan-2-yl) ester (rac-10) in quantitative yield. The latter was quantitatively converted into rac-1 by treatment with aqueous 6 N HCl and then ammonia solutions. The same transformations of (1R,2R)-9 [prepared by deracemization of rac-9 with (-)-dibenzoyl-L-tartaric acid (DBT)] proceeded without loss of the optical activity. Deracemization of rac-1 applying (+)-(5)-L-mandelic acid (MA) furnished (1R,2R)-1 and (1s,2s)-1 in 34 and 17% yield, respectively, with e.e. ≥ 98 and 97.6%, respectively. Procedures for recycling of the chiral auxiliaries DBT and MA are also described. The structures of key intermediates were confirmed by X-ray crystal structure analysis.
- Kozhushkov, Sergei I.,Yufit, Dmitrii S.,De Meijere, Armin
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p. 255 - 265
(2007/10/03)
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- Asymmetric transfer hydrogenation of ketones using amino alcohol and monotosylated diamine derivatives of indane
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A series of 1,2-amino alcohol and 1,2-monotosylated diamine derivatives of indane have been applied as ligands in the asymmetric ruthenium(II)-catalysed transfer hydrogenation reaction of a series of ketones. Of these, the cis-1-aminoindan-2-ol derivative gives some of the highest asymmetric inductions reported for any amino alcohol ligand in this application.
- Palmer, Matthew J.,Kenny, Jennifer A.,Walsgrove, Tim,Kawamoto, Aparecida M.,Wills, Martin
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p. 416 - 427
(2007/10/03)
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- Stereoselective dioxygenase-catalysed benzylic hydroxylation at prochiral methylene groups in the chemoenzymatic synthesis of enantiopure vicinal aminoindanols
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Enantiopure benzylic alcohols containing two stereogenic centres in a cis- relationship result from stereoselective monohydroxylation of achiral 2- substituted indans in cultures of Pseudomonas putida UV4 and are used in the chemoenzymatic synthesis of both cis- and trans-aminoindanol enantiomers.
- Boyd, Derek R.,Sharma, Narain D.,Bowers, Nigel I.,Goodrich, Peter A.,Groocock, Melanie R.,Blacker, A.John,Clarke, David A.,Howard, Tina,Dalton, Howard
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p. 1559 - 1562
(2007/10/03)
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- Synthesis and protein kinase C inhibitory activities of indane analogs of balanol
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Regio- and stereoisomeric indane analogs (4-6) of balanol (-)-1, a potent protein kinase C (PKC) inhibitor, were synthesized in which the perhydroazepine of balanol was replaced by an indane nucleus. Analog (-)-4 and its racemic regioisomer 6 were found to have highly potent PKC inhibitory activities. In addition, compound (-)-4 displayed excellent kinase selectivity for PKC over PKA.
- Hu, Hong,Hollinshead, Sean P.,Hall, Steven E.,Kalter, Kiyomi,Ballas, Lawrence M.
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p. 973 - 978
(2007/10/03)
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- Inhibitors of human immunodeficiency virus type 1 protease containing 2- aminobenzyl-substituted 4-amino-3-hydroxy-5-phenylpentanoic acid: Synthesis, activity, and oral bioavailability
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Systematic modifications of HIV protease inhibitor (2R,3S,4S)-4- [[(benzyloxycarbonyl)-L-valyl]amino]-3-hydroxy-2-[(4-methoxybenzyl)amino]-5- (phenylpentanoyl)-L-valine 2-(aminomethyl)-benzimidazole amide led to a novel series of inhibitors with a shortened, modified carboxy terminus. Their synthesis, in vitro enzyme inhibitory data, and antiviral activities are reported. Of particular interest are derivatives featuring the (1S,2R)-1- amino-2-hydroxyindan moiety at the P2'-position since some of them exhibit substantial oral bioavailability in mice. The influence of aqueous solubility and structural parameters on the oral resorption of the inhibitors is discussed. Optimum enhancement of oral bioavailability was observed with L- tert-leucine in P2-position, resulting in the discovery of (2R,3S,4S)-4- [[(benzyloxycarbonyl)-L-tert-leucyl]amino]-3-hydroxy-2-[(4- methoxybenzyl)amino]-5-phenylpentanoic acid (1S,2R)-1-amino-2-hydroxyindan amide which combines high antiviral activity (IC50 = 250 nM) with a good pharmacokinetic profile (AUC = 82.5 μM · h at a dose of 125 mg/kg po in mice).
- Lehr,Billich,Charpiot,Ettmayer,Scholz,Rosenwirth,Gstach
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p. 2060 - 2067
(2007/10/03)
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