- Asymmetric Reduction of α-Ketoimines with Oxazaborolidine Catalysts: A Novel, Practical Approach to Chiral Arylethanolamines
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Asymmetric borane reduction of α-ketoimines with oxazaborolidine catalysts has been studied.The ee's of the resulting arylethanolamines are uo to 93percent using 20 molpercent of the catalyst.
- Hong, Yaping,Gao, Yun,Nie, Xiaoyi,Zepp, Charles M.
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- Efficient Synthesis of 2-Amino-1-Arylethanols Through a Lewis Base-Catalyzed SiCl4-Mediated Asymmetric Passerini-Type Reaction
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We herein report, a practical and efficient strategy for the synthesis of enantiomerically enriched 2-amino-1-arylethanols, a structural motif commonly encountered in the family of β-adrenergic blockers or agonists, through a Lewis base-catalyzed SiClsub
- Ayad, Tahar,Gernet, Aurélie,Pirat, Jean-Luc,Ratovelomanana-Vidal, Virginie,Virieux, David
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supporting information
p. 6497 - 6500
(2020/10/30)
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- Process for preparing beta-aminoalcohol from terminal olefin
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The invention provides a method for preparing beta-aminoalcohol from terminal olefin. The method comprises the following steps: with the terminal olefin as a raw material, adding dibromohydantoin, conducting stirring, and then adding organic amine to obtain corresponding beta-aminoalcohol. The method has the advantages of mild conditions, easy operation, cheap raw materials, and wide application prospect.
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Paragraph 0031-0033; 0042
(2020/06/17)
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- Method for Ir/f-amphox high-efficiency synthesis of chiral α- C-amino alcohol by virtue of catalytic oxidation 1,2- of P-aminoketone by using one-aminoketone
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The invention discloses a method for efficiently synthesizing chiral 1,2-amino alcohol by catalyzing alpha-aminoketone through Ir/f-amphox. A ligand f-amphox used by the method can be more easily synthesized; the reaction has the characteristics of enanti
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Paragraph 0064-0066
(2020/01/03)
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- Method for preparing beta-arylamino alcohol drugs such as tulobuterol, clorprenaline, dichloroisoprenaline and sotalol
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The invention provides a method for preparing beta-arylamino alcohol drugs such as tulobuterol, clorprenaline, dichloroisoprenaline and sotalol. The beta-arylamino alcohol drugs have a chemical structure represented by a formula 4 shown in the description. The method comprises the following steps: (1) reacting arylethanone represented by a formula 1 shown in the description with a halogenating agent and sulfoxide to obtain arylglyoxal represented by a formula 2 shown in the description and or 1,1-dihydroxyarylethanone represented by a formula 3 shown in the description; and (2) performing a nucleophilic addition reaction on the arylglyoxal represented by the formula 2 and/or the 1,1-dihydroxyarylethanone represented by the formula 3 and an amine compound having a chemical formula of R1-NH2, and performing a reductive amination reaction in the presence of a reducing agent to obtain the beta-arylamino alcohol drugs.
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Paragraph 0088; 0106; 0107; 0108
(2019/08/30)
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- TPT sulfonate, a single, oral dose schistosomicidal prodrug: In vivo efficacy, disposition and metabolic profiling
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Treatment of schistosomiasis relies precariously on just one drug, praziquantel (PZQ). In the search for alternatives, 15 S-[2-(alkylamino)alkane] thiosulfuric acids were obtained from a previous research program and profiled in mice for efficacy against both mature (>42-day-old) and juvenile (21-day-old) Schistosoma mansoni using a screening dose of 100 mg/kg PO QDx4. One compound, S-[2-(tert-butylamino)-1-phenylethane] thiosulfuric acid (TPT sulfonate), was the most effective by decreasing female and male worm burdens by ≥ 90% and ≥46% (mature), and ≥89% and ≥79% (juvenile), respectively. In contrast, PZQ decreased mature female and male worm burdens by 95% and 94%, respectively, but was ineffective against juvenile stages. Against 7-day-old lung-stage worms, TPT sulfonate was only effective at twice the dose decreasing female and male burdens by 95 and 80%, respectively. Single oral doses at 400 and/or 600 mg/kg across various developmental time-points (1-, 7-, 15-, 21- and/or 42 day-old) were consistent with the QD x4 data; efficacy was strongest once the parasites had completed lung migration, and female and male burdens were decreased by at least 90% and 80%, respectively. In vitro, TPT sulfonate is inactive against the parasite suggesting a pro-drug mechanism of action. In mice, TPT sulfonate is fully absorbed and subject to rapid, non-CYP-mediated, first-pass metabolism that is initiated by desulfation and yields a series of metabolites. The initially-formed free thiol-containing metabolite, termed TP thiol, was chemically synthesized; it dose-dependently decreased S. mansoni and Schistosoma haematobium motility in vitro. Also, when administered as a single 50 mg/kg IP dose, TP thiol decreased 33-day-old S. mansoni female and male burdens by 35% and 44%, with less severe organomegaly. Overall, TPT sulfonate's efficacy profile is competitive with that of PZQ. Also, the characterization of a parasiticidal metabolite facilitates an understanding and improvement of the chemistry, and identification of the mechanism of action and/or target.
- Wolfe, Alan R.,Neitz, R. Jeffrey,Burlingame, Mark,Suzuki, Brian M.,Lim,Scheideler, Mark,Nelson, David L.,Benet, Leslie Z.,Caffrey, Conor R.
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p. 571 - 586
(2018/11/30)
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- Continuous and convergent access to vicinyl amino alcohols
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Five active pharmaceutical ingredients (APIs) containing the vicinyl amino alcohol moiety were synthesized using a convergent chemical assembly system. The continuous system is composed of four flow reaction modules: biphasic oxidation, Corey-Chaykovsky epoxidation, phenol alkylation, and epoxide aminolysis. Judicious choice of reagents and module order allowed for two classes of β-amino alcohols, aryl and aryloxy, to be synthesized in good (27-69%) overall yields.
- Nobuta, Tomoya,Xiao, Guozhi,Ghislieri, Diego,Gilmore, Kerry,Seeberger, Peter H.
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p. 15133 - 15136
(2015/10/12)
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- One-pot synthesis of N-substituted β-amino alcohols from aldehydes and isocyanides
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A practical two-stage one-pot synthesis of N-substituted β-amino alcohols using aldehydes and isocyanides as starting materials has been developed. This method features mild reaction conditions, broad scope, and general tolerance of functional groups. Based on a less common central carbon-carbon bond disconnection, this protocol complements traditional approaches that involve amines and various carbon electrophiles (epoxides, α-halo ketones, β-halohydrins). Medicinally relevant products can be prepared in a concise and efficient way from simple building blocks, as demonstrated in the synthesis of the antiasthma drug salbutamol. Upgrading the synthesis to an enantioselective variant is also feasible.
- Cioc, R?zvan C.,Van Der Niet, Daan J. H.,Janssen, Elwin,Ruijter, Eelco,Orru, Romano V.A.
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supporting information
p. 7808 - 7813
(2015/05/20)
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- Synthesis of chiral oxazolidinone derivatives through lipase-catalyzed kinetic resolution
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The synthesis of enantioenriched oxazolidinone derivatives through lipase-catalyzed kinetic resolution is described. The synthesis comprised a two-step, cascade acylation in one pot, resulting in a range of oxazolidinone derivatives in good yields and exc
- Zhang, Yan,Zhang, Yang,Ren, Yansong,Ramstr?m, Olof
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- Efficient preparation of α-ketoacetals
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The Weinreb amides 2a,b were prepared from the a,a-dimethoxyacetic acids 1c,d. A number of representative nucleophilic additions (RMgX and RLi) on 2 afforded a-ketoacetals 3a-j in 70-99% yield. These compounds represent a versatile arrangement of functional groups of significant synthetic value, as demonstrated in the synthesis of (±)-salbutamol.
- Ayala-Mata, Francisco,Barrera-Mendoza, Citlalli,Jimenez-Vazquez, Hugo A.,Vargas-Diaz, Elena,Zepeda, L. Gerardo
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p. 13864 - 13878
(2013/03/13)
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- CONTINUOUS FLOW SYNTHESIS OF AMINO ALCOHOLS USING MICROREACTORS
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The present invention provides various methods for the synthesis of chemical species in a microreactor environment. In some cases, reaction products of the present invention may be valuable as intermediates and/or products in pharmaceutical and polymer research. For example, the method may involve the synthesis of amino alcohols within a microchannel. Embodiment described herein may allow for reactions with significantly shorter reaction times and increased efficiency.
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Page/Page column 9-10
(2011/06/10)
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- Asymmetric synthesis of β-amino alcohols by the transfer hydrogenation of α-keto imines
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The asymmetric transfer hydrogenation of representative aryl and benzofuranyl 2-tert-butylaminoethanones with formic acid-triethylamine, catalyzed by RhCl[(R,R)-TsDPEN](C5Me5), produced the corresponding β-tert-butylamino alcohols in 97-99% ee. A short asymmetric synthesis of (R)-bufuralol, a potent β-adrenergic receptor antagonist, is described. This approach to β-amino alcohols from ketones circumvents the halogenation-reduction-amination sequence.
- Tafelska-Kaczmarek, Agnieszka,Prewysz-Kwinto, Andrzej,Skowerski, Krzysztof,Pietrasiak, Katarzyna,Kozakiewicz, Anna,Zaidlewicz, Marek
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scheme or table
p. 2244 - 2248
(2010/11/03)
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- Aminolysis of epoxides in a microreactor system: A continuous flow approach to β-Amino alcohols
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The use of a continuous flow microreactor for β-amino alcohol formation by epoxide aminolysis is evaluated. Comparison to microwave batch reactions reveals that conditions obtainable in the microreactor can match or improve yields in many cases. By increasing the pressure of the system, maximum temperatures can also exceed those accessible using a microwave unit. The use of a microreactor for epoxide aminolysis reactions in the synthesis of two pharmaceutical relevant compounds is described.
- Jensen, Klavs F.,Bedore, Matthew W.,Zaborenko, Nikolay,Jamison, Timothy F.
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experimental part
p. 432 - 440
(2011/04/22)
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- Metallocene catalyzed synthesis of fungistatic vicinal aminoalcohols under solvent free conditions
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Group 4 and 5 metallocenes, Cp2TiCl2, Cp 2ZrCl2 and Cp2VCl2, have been evaluated as catalyst in the solvent free, room temperature, preparation of vicinal aminoalcohols. The regioselectivity of the reaction and the fungistatic activity of the prepared compounds against Botrytis cinerea and Colletotrichum gloeosporioides are discussed.
- Mancilla, Gabriela,Durán-Patrón, Rosa M.,Macías-Sánchez, Antonio J.,Collado, Isidro G.
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scheme or table
p. 6820 - 6822
(2011/01/04)
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- A facile and efficient synthesis of β-amino alcohols using 2,2,2-trifluoroethanol as a metal-free and reusable medium
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Trifluoroethanol was used as a reusable catalyst and medium for the ring opening of epoxides using aliphatic and aromatic amines as nucleophile under mild conditions to give the corresponding β-amino alcohols in high yields and regioselectivity.
- Khaksar, Samad,Heydari, Akbar,Tajbakhsh, Mahmood,Bijanzadeh, Hamid Reza
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experimental part
p. 106 - 110
(2010/03/03)
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- Hydrophobic amplification of noncovalent organocatalysis
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The effects of hydrogen-bonding organocatalysts and water for the acceleration of epoxide openings with a variety of nucleophiles are additive and lead to excellent yields of the catalyzed reactions in water. The Royal Society of Chemistry 2006.
- Kleiner, Christian M.,Schreiner, Peter R.
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p. 4315 - 4317
(2007/10/03)
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- Enantioselective nitrile anion cyclization to substituted pyrrolidines. A highly efficient synthesis of (3S,4R)-N-tert-butyl-4-arylpyrrolidine-3- carboxylic acid
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(Chemical Equation Presented) A practical asymmetric synthesis of N-tert-butyl disubstituted pyrrolidines via a nitrile anion cyclization strategy is described. The five-step chromatography-free synthesis of (3S,4R)-1-tert-butyl-4-(2,4-difluorophenyl)pyrr
- Chung, John Y. L.,Cvetovich, Raymond,Amato, Joseph,McWilliams, J. Christopher,Reamer, Robert,DiMichele, Lisa
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p. 3592 - 3601
(2007/10/03)
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- Highly chemoselective addition of amines to epoxides in water
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(Chemical Equation Presented) Aminolysis of a variety of epoxides by aliphatic and aromatic amines in water, in the absence of any catalyst with high yields, is reported. β-Amino alcohols were formed under mild conditions with high selectivity and in excellent yields.
- Azizi, Najmodin,Saidi, Mohammad R.
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p. 3649 - 3651
(2007/10/03)
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- Solid lithium perchlorate as a powerful catalyst for the synthesis of β-aminoalcohols under solvent-free conditions
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Lithium perchlorate catalyzed the ring opening of epoxides with amines to provide the corresponding β-aminoalcohols in excellent yields with high regioselectivity. The reaction proceeds rapidly under mild and neutral conditions and worked well with primary, secondary, aliphatic, aromatic, and hindered amines in short times at room temperature, in the absence of solvent.
- Azizi, Najmodin,Saidi, Mohammad R.
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p. 505 - 507
(2007/10/03)
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- Electronic effects in olefin oxidation by imidoosmium(VIII) compounds
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Imido osmium(VIII) complexes are versatile oxidants for C-C double bond functionalisation. Despite their structural similarity with OsO4 their reactivity cannot always be compared with this seminal reagent. Detailed investigations including kinetic competition experiments are presented that uncover the electronic and steric preferences of osmium imido complexes. The different behaviour of OsO4 and its imido derivatives towards tertiary amines and diamines is clarified. Hammett correlation studies reveal that the reactivity spectrum of the respective oxidants ranges from a strongly electrophilic behaviour in the case of OsO4 to a rather nucleophilic character as encountered for OsO(NtBu)3. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
- Muniz, Kilian
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p. 2243 - 2252
(2007/10/03)
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- Synthesis of chiral non-racemic 1,2-diamines from O-acetyl mandelic acid: Application in enantioselective deprotonation of epoxides and diethylzinc addition to aldehydes
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A variety of 1,2-diamines were synthesized from readily available O-acetyl mandelic acid. These diamines were used in the synthesis of key intermediates for the preparation of (-)-utenone A and carbovir involving enantioselective deprotonation of epoxides. The addition of Et2Zn catalysed by some of these diamines was also studied and although ees were not high, some interesting observations were made in the outcome of the stereochemistry of the product.
- Saravanan,Bisai, Alakesh,Baktharaman,Chandrasekhar,Singh, Vinod K
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p. 4693 - 4706
(2007/10/03)
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- Diisopropoxyaluminium trifluoroacetate: A new promoter for aminolysis of epoxides
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Aminolysis of symmetrical as well as unsymmetrical epoxides using various amines in the presence of diisopropoxyaluminium trifluoroacetate (DIPAT) as a new promoter gave 1,2-amino alcohols in excellent yields at room temperature with good to excellent selectivities.
- Rampalli, Sriram,Chaudhari, Sachin S.,Akamanchi, Krishnacharya G.
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- Lithium trifluoromethanesulfonate-catalysed aminolysis of oxiranes
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The aminolysis of oxiranes was found to be catalysed by lithium trifluoromethanesulfonate in acetonitrile solutions. This salt turned out to be an excellent substitute for the unsafe lithium perchlorate.
- Auge, Jacques,Leroy, Frederic
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p. 7715 - 7716
(2007/10/03)
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- Organoimido Complexes as a New Class of Lewis Acid Catalysts for Regioselective Ring-Opening of Epoxides
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Organoimido complexes of Group VI transition metals were found to catalyze ring-opening of epoxides by trimethylsilyl azide and amines with good regioselectivities.
- Leung, Wa-Hung,Chow, Ernest K. F.,Wu, Man-Ching,Kum, Polly W. Y.,Yeung, Lam-Lung
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p. 107 - 108
(2007/10/02)
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- Ring Opening Reactions of Epoxides Catalyzed by Samarium Iodides
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SmI2(THF)2 catalyzes the ring opening of epoxides by trimethylsilylazide, trimethylsilylcyanide and primary and secondary amines.High regioselectivities are observed in specific cases.
- Weghe, Pierre Van de,Collin, Jacqueline
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p. 1649 - 1652
(2007/10/02)
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- Lanthanide(III) trifluoromethanesulfonates as extraordinarily effective new catalysts for the aminolysis of 1,2-epoxides
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Lanthanide(III) trifluoromethanesulfonates (triflates), such as Yb(OTf)3, Nd(OTf)3 and Gd(OTf)3, catalyze in a extraordinarily efficient way the aminolysis of 1,2-epoxides, affording the corresponding β-amino alcohols, at
- Chini, Marco,Crotti, Paolo,Favero, Lucilla,Macchia, Franco,Pineschi, Mauro
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p. 433 - 436
(2007/10/02)
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- The Reaction of Phenylglyoxal with Primary Aliphatic and Aromatic Amines. Synthesis of Phenylglyoxal Monoimines and some Derivatives.
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Condensation of phenylglyoxal with primary aliphatic amines yields the related keto-aldimines.When primary aromatic amines are used, aldimines, amino-hydroxy-ketones, diamino-ketones, and alkoxy-amino-ketones are obtained depending upon the nature of the amine and the experimental conditions.Alternatively the monoimines can be obtained by dehydration of C-hydroxyphenacylarylamines and by demethanolation of C-methoxyphenacylarylamines both on treatment with Pd/C catalyst.Reduction of phenylglyoxal monoimines with sodium borohydride yielded H-substituted 1-phenyl-2-aminoethanols and 1,3-dipolar cycloaddition of the imines with p-chlorobenzonitrile oxide afforded 4-substituted 5-benzoyl-3-(p-chlorophenyl)-4,5-dihydro-1,2,4-oxadiazoles.
- Alcaide, Benito,Escobar, Gerardo,Perez-Ossorio, Rafael,Plumet, Joaquin,Sanz, Dionisia
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p. 1466 - 1488
(2007/10/02)
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- Removal of Toluene-p-sulphonyl Groups from Sulphonamides. Part 5. Reactions of Phenylglyoxal Imines and some Tosylimines
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Phenylglyoxal anil monomers have been shown to react with several nucleophilic reagents and the structures of the products have been elucidated.Various N-tosylarylimines also react with nucleophiles to give useful products.Phenacylimidates underwent cycloadditions with diphenylketen; such reactions gave complex results with phenacylimines, but the latter reacted with conjugated dienes in the presence of BF3 to give cycloaddition products in good yield.
- McKay, William R.,Proctor, George R.
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p. 2443 - 2450
(2007/10/02)
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