- Copper(I)-Catalyzed Asymmetric Vinylogous Aldol-Type Reaction of Allylazaarenes
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A vinylogous aldol-type reaction of allylazaarenes and aldehydes is disclosed that affords a series of chiral γ-hydroxyl-α,β-unsaturated azaarenes in moderate to excellent yields with high to excellent regio- and enantioselectivities. With (R,RP)-TANIAPHOS and (R,R)-QUINOXP* as the ligand, the carbon-carbon double bond in the products is generated in (E)-form. With (R)-DTBM-SEGPHOS as the ligand, (Z)-form carbon-carbon double bond is formed in the major product. In this vinylogous reaction, aromatic, α,β-unsaturated, and aliphatic aldehydes are competent substrates. Moreover, a variety of azaarenes, such as pyrimidine, pyridine, pyrazine, quinoline, quinoxaline, quinazoline, and benzo[d]imidazole are well-tolerated. At last, the chiral vinylogous product is demonstrated as a suitable Michael acceptor towards CuI-catalyzed nucleophilic addition with organomagnesium reagents.
- Wang, Si-Qing,Liu, Zong-Ci,Yue, Wen-Jun,Yin, Liang
-
supporting information
p. 4604 - 4608
(2021/01/21)
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- Chiral Ion-Pair Organocatalyst-Promoted Efficient Enantio-selective Reduction of α-Hydroxy Ketones
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The enantioselective reduction of α-hydroxy ketones with catecholborane has been developed employing 5 mol% of an 1,1′-bi-2-naphthol (BINOL)-derived ion-pair organocatalyst. This methodology provides a straightforward access to the corresponding aromatic 1,2-diols in high yields (up to 90%) with excellent enantioselectivities (up to 97%). Furthermore, the α-amino ketones also could be reduced with moderate ee values under mild reaction condition. (Figure presented.).
- Zhang, Yiliang,He, Li,Shi, Lei
-
supporting information
p. 1926 - 1931
(2018/03/27)
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- Organocatalytic direct asymmetric crossed-aldol reactions of acetaldehyde in aqueous media
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A new type of diarylprolinol-based catalyst, which contains a dioctylamino group in the presence of a newly developed ionic liquid supported (ILS) benzoic acid as cocatalyst, is shown to be an effective catalytic system for the asymmetric direct crossed-aldol reaction of acetaldehyde in aqueous media using brine. For the reactions studied, the catalyst loading could be reduced to 5 mol %; high yields (up to 97%) and high enantioselectivities (up to 92% ee) were also achieved for a wide variety of aromatic aldehyde.
- Qiao, Yupu,Chen, Qiankun,Lin, Sirong,Ni, Bukuo,Headley, Allan D.
-
supporting information
p. 2693 - 2696
(2013/04/24)
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- Highly diastereo- and enantioselective allylboration of aldehydes using α-substituted allyl/crotyl pinacol boronic esters via in situ generated borinic esters
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Readily available, α-substituted allyl/crotyl pinacol boronic esters often give low E/Z selectivity (with Z favored) in reactions with aldehydes. We found that addition of nBuLi to the pinacol boronic ester followed by trapping of the alkoxide with TFAA leads to an intermediate allyl borinic ester which undergoes allylboration with very high E selectivity. The substrate scope includes primary to tertiary alkyl α-substituents, crotyl substrates, and the previously unreported β-methallyl pinacol boronic esters. The latter give very high Z selectivity under standard conditions which is completely reversed to high E selectivity under the new conditions. Monitoring the reaction by 11B NMR confirmed that the reaction proceeds through a borinic ester intermediate.
- Chen, Jack L.-Y.,Scott, Helen K.,Hesse, Matthew J.,Willis, Christine L.,Aggarwal, Varinder K.
-
supporting information
p. 5316 - 5319
(2013/05/21)
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- Palladium-catalyzed synthesis of enantiomerically pure α-substituted allylboronic esters and their addition to aldehydes
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Tartrate-derived boronic esters 2 can be subjected to palladium-catalyzed carbonyl allylations with SnCl2 to obtain enantiomerically pure α-substituted allylboronic esters 8 and 9. The reaction proceeds regioselectively and with high, simple diastereoselectivity to form anti-products. Their addition to aldehydes yields enantiomerically enriched homoallylic alcohols 17 and 18, respectively. Synthesis, characterization, and a mechanistic rational is presented here.
- Fernandez, Enrique,Pietruszka, Joerg,Frey, Wolfgang
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supporting information; experimental part
p. 5580 - 5589
(2010/11/17)
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- Organic metal compound and process for preparing optically-active alcohols using the same
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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; 12
(2009/04/24)
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- Diastereo- and enantiomerically pure allylboronates: Their synthesis and scope
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Allylboronates are highly attractive reagents for allyl additions. Enantiomerically pure, stable reagents with a stereogenic centre in a-position to boron are especially versatile, albeit often difficult to synthesize. Starting from boron-containing allyl alcohols 6 and 7, which are discussed in detail herein, a set of reagents were obtained via [3,3]-sigmatropic rearrangements and consecutive transformations in the side chain. The configurations could be established first by chemical correlation, but also by X-ray crystallography (16, 18, 34, and 39). Allyl additions were performed resulting in the formation of predominantly (Z)-configured homoallylic alcohols (31, 43-45) with high enantiomeric excess. Detailed investigations on the matched-mismatched interaction between the reagents 15/16 (and ent-15/ent-16, respectively) and isopropylidene glyceraldehyde 42 d are presented.
- Pietruszka, Joerg,Schoene, Niklas,Frey, Wolfgang,Grundl, Li
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experimental part
p. 5178 - 5197
(2009/07/18)
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- Lewis base activation of Lewis acids: Catalytic, enantioselective vinylogous aldol addition reactions
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(Chemical Equation Presented) The generality of Lewis base catalyzed, Lewis acid mediated, enantioselective vinylogous aldol addition reactions has been investigated. The combination of silicon tetrachloride and chiral phosphoramides is a competent catalyst for highly selective additions of a variety of α,β-unsaturated ketone-, 1,3-diketone-, and α,β- unsaturated amide-derived dienolates to aldehydes. These reactions provided high levels of γ-site selectivity for a variety of substitution patterns on the dienyl unit. Both ketone- and morpholine amide-derived dienol ethers afforded high enantio- and diastereoselectivity in the addition to conjugated aldehydes. Although α,β-unsaturated ketone-derived dienolate did not react with aliphatic aldehydes, α,β-unsaturated amide-derived dienolates underwent addition at reasonable rates affording high yields of vinylogous aldol product. The enantioselectivities achieved with the morpholine derived-dienolate in the addition to aliphatic aldehydes was the highest afforded to date with the silicon tetrachloride-chiral phosphoramide system. Furthermore, the ability to cleanly convert the morpholine amide to a methyl ketone was demonstrated.
- Denmark, Scott E.,Heemstra Jr., John R.
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p. 5668 - 5688
(2008/02/10)
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- Phosphoramidate and phosphate prodrugs of (-)-β-D-(2R,4R)-dioxolane- thymine: Synthesis, anti-HIV activity and stability studies
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A series of phosphoramidate and phosphate prodrugs of DOT were synthesized via dichlorophosphate or H-phosphonate chemistry and evaluated for their anti-HIV activity against LAI M184V mutants in PBM cells as well as for their cytotoxicity. The antiviral and cytotoxic profiles of the prodrugs were compared with that of the parent compound (DOT), and it was found that four aryl phosphoramidates 5, 18, 20, and 26 showed a significant enhancement (8- to 12-fold) in anti-HIV activity without cytotoxicity. Chemical stability of these prodrugs was evaluated in phosphate buffer at pH values of biological relevance (i.e., pH 2.0 and 7.4). Enzymatic hydrolysis was also studied in esterase or lipase in buffer solution. Chemical stability studies indicate that the phosphoramidates have good chemical stability at pH 2.0 and at pH 7.4 phosphate buffer. Phosphoramidate prodrugs were hydrolyzed in vitro by esterase or lipase and found to be better substrates for lipases than for esterases. 1,3-Diol cyclic phosphates showed potent anti-HIV activity without increasing the cytotoxicity compared with that of DOT and have good chemical and enzymatic stability. Long-chain lipid phosphates, although showed potent anti-HIV activity, exhibited increased cytotoxicity.
- Liang, Yuzeng,Narayanasamy, Janarthanan,Schinazi, Raymond F.,Chu, Chung K.
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p. 2178 - 2189
(2007/10/03)
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- Identification of potent type I MetAPs inhibitors by simple bioisosteric replacement. Part 2: SAR studies of 5-heteroalkyl substituted TCAT derivatives
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Systematic SAR studies on the thiazole ring 5-substituent of TCAT derivatives revealed that the introduction of a β-alkoxy or an amino group enhanced the inhibitory activity significantly. The present compounds are representative of specific Co(II)-MetAP1 inhibitors. Before the physiologically relevant metal ions for MetAPs are established, these small molecular compounds could be used as tools for detailed biological studies.
- Cui, Yong-Mei,Huang, Qing-Qing,Xu, Jie,Chen, Ling-Ling,Li, Jing-Ya,Ye, Qi-Zhuang,Li, Jia,Nan, Fa-Jun
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p. 4130 - 4135
(2007/10/03)
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- Candida Rugosa lipase-catalyzed kinetic resolution of β-hydroxy- β-arylpropionates and δ-hydroxy-δ-aryl-β-oxo-pentanoates
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A simple and convenient method was reported for the preparation of optically active β-hydroxy-β-arylpropionates, δ-hydroxy-δ- aryl-β-oxo-pentanoates and their butyryl derivatives via CRL-catalyzed hydrolysis. The optically active products are potential precursors of some chiral pharmaceuticals and natural products.
- Xu, Chengfu,Yuan, Chengye
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p. 2169 - 2186
(2007/10/03)
-
- Assembly intermediates in polyketide biosynthesis: Enantioselective syntheses of β-hydroxycarbonyl compounds
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A versatile approach for the enantioselective synthesis of functionalised β-hydroxy N-acetylcysteamine thiol esters has been developed which allows the facile incorporation of isotopic labels. It has been shown that a remarkable reversal of selectivity occurs in the titanium mediated aldol reaction of acyloxazolidinone 7 using either (S)- or (R)-tert-butyldimethylsilyloxybutanal. The aldol products are valuable intermediates in the synthesis of 4-hydroxy-6-substituted δ-lactones. The Royal Society of Chemistry 2005.
- Sann, Christine Le,Munoz, Dulce M.,Saunders, Natalie,Simpson, Thomas J.,Smith, David I.,Soulas, Florilene,Watts, Paul,Willis, Christine L.
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p. 1719 - 1728
(2007/10/03)
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- Remote asymmetric induction with vinylketene silyl N,O-acetal
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A highly regio- and diastereoselective TiCl4-mediated vinylogous Mukaiyama aldol reaction using the chiral vinylketene silyl N,O-acetal has been developed. The present vinylogous Mukaiyama aldol reaction provides a unique and effective means of
- Shirokawa, Shin-Ichi,Kamiyama, Masato,Nakamura, Tomoaki,Okada, Masakazu,Nakazaki, Atsuo,Hosokawa, Seijiro,Kobayashi, Susumu
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p. 13604 - 13605
(2007/10/03)
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- Chemoenzymatic synthesis2 of both enantiomers of fluoxetine, tomoxetine and nisoxetine: Lipase-catalyzed resolution of 3-aryl-3-hydroxypropanenitriles
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A facile preparation of (±)-3-hydroxy-3-phenylpropanenitrile has been carried out by ring-opening of styrene oxide with NaCN in aqueous ethanol. Subsequent kinetic resolution of this material via lipase-mediated transesterification gave the S-alcohol and R-acetate in excellent yields and high enantioselectivities, particularly with lipase PS-C 'Amano' II. The effect of solvents and immobilization of the lipase has also been investigated. It is interesting to note that the use of immobilized lipase for this transesterification process in hydrophobic solvents (diisopropyl ether, toluene and hexane) enhanced the reaction rate drastically and gave optimal yields with high enantioselectivity (>99%). Moreover, enantiopure 3-hydroxy-3-phenylpropanenitrile products have been converted via enantioconvergent routes into the (R)- and (S)-enantiomers of the important anti-depressants fluoxetine, tomoxetine, nisoxetine and norfluoxetine.
- Kamal, Ahmed,Khanna,Ramu
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p. 2039 - 2051
(2007/10/03)
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- Titanocene-catalyzed asymmetric ketone hydrosilylation: The effect of catalyst activation protocol and additives on the reaction rate and enantioselectivity
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The efficient asymmetric hydrosilylation of ketones with a chiral titanocene catalyst has been realized. In this procedure, (R,R)-ethylenebis(tetrahydroindenyl) titanium difluoride (1) was used as the precatalyst, and alcohol additives were employed. Arom
- Yun, Jaesook,Buchwald, Stephen L.
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p. 5640 - 5644
(2007/10/03)
-
- A general synthesis of homochiral β-hydroxy N-acetylcysteamine thioesters
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A convenient and efficient route for the enantioselective synthesis of functionalised β-hydroxy N-acetylcysteamine thioesters is described. The route allows the facile incorporation of vicinal 13C labelling to produce intermediates required for biosynthetic studies on a wide range of polyketide metabolites, e.g. 6-MSA, monocerin, colletodiol and strobilurins.
- Le Sann, Christine,Simpson, Thomas J.,Smith, David I.,Watts, Paul,Willis, Christine L.
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p. 4093 - 4096
(2007/10/03)
-
- Methods for treating depression and other disorders using optically pure R (-) fluoxetine and monoamine oxidase inhibitor
-
A method and composition are utilizing the pure R(-) isomer of fluoxetine which is a potent antidepressant and appetite suppressant substantially free of adverse effects. In addition, a method and composition are disclosed utilizing the pure R(-) isomer of fluoxetine which is useful to treat migraine headaches, pain, in particular chronic pain, psychoactive substance abuse disorders and obsessive compulsive disorders.
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- Highly efficient enzymatic resolution of homoallyl alcohols leading to a simple synthesis of optically pure fluoxetine and related compounds
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A practical method for enzymatic resolution of homoallyl alcohols and its utility in the synthesis of optically pure fluoxetine and related compounds is reported.
- Master, Hosang E.,Newadkar,Rane,Kumar, Ashok
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p. 9253 - 9254
(2007/10/03)
-
- 1,5-Asymmetric induction in reactions between aldehydes and (tributyl)stannane promoted by tin(IV) chloride
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(tributyl)stannane 18 has been prepared from di-O-isopropylidene-D-mannitol 8.Oxidative cleavage of the mannitol derivative followed by condensation with triethyl phosphonoacetate and reduction gav
- Maguire, Robert J.,Thomas, Eric J.
-
p. 2477 - 2486
(2007/10/02)
-
- Ruthenium-phosphine complex and process for producing optically active 1-substituted-1,3-propanediols using the same as a catalyst
-
A ruthenium-phosphine complex is disclosed, represented by formula (I): where R1 -BINAP represents a tertiary phosphine represented by formula (II): STR1 wherein R1 represents a phenyl group which may be substituted with a lower alkyl group or a halogen atom at the p-position and/or m-position. A process for producing an optically active 1-substituted-1,3-propanediol is also disclosed, comprising hydrogenating a 3-substituted-3-oxopropanol or 3-substituted-3-oxopropanal in the presence of the ruthenium-phosphine complex of formula (I).
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-
- Process for producing optically active 1-substituted-1,3-propanediols using ruthenium-phosphine complex as a catalyst
-
A process for producing an optically active 1-substituted-1,3-propanediol is disclosed, comprising hydrogenating a 3-substituted-3-oxopropanol or 3-substituted-3-oxopropanal in the presence of a ruthenium-phosphine complex represented by formula (I): wherein R1 -BINAP represents an optically active tertiary phosphine represented by formula (II): STR1 wherein R1 represents a phenyl group which may be substituted with a lower alkyl group or a halogen atom at the p-position and/or m-position.
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-
- Total Synthesis of Mugineic Acid. Efficient Use of the Phenyl Group as the Carboxyl Synthon
-
Stereoselective total synthesis of mugineic acid (1), a unique phytosiderophore from roots of barley, has been achieved from readily available (2S,3S)- and (2R,3R)-2,3-epoxycinnamyl alcohols (5) and (6).The key step is the oxidation of the phenyl group to the carboxylic acid by use of the ruthenium trichloride-sodium metaperiodate system.
- Matsuura, Fumiyoshi,Hamada, Yasumasa,Shioiri, Takayuki
-
p. 8211 - 8222
(2007/10/02)
-
- Directed Asymmetric Reduction of a Carbonyl Group via a New Homochiral Boronate Ester
-
Homochiral β-boronate carbonyl derivative 4 directs the asymmetric reduction of the ketone moiety, providing 89percent enantiomeric excess of the (S)-diol 6, using borane-tetrahydrofuran as the reducing agent.
- Mears, Richard J.,Whiting, Andrew
-
p. 8155 - 8156
(2007/10/02)
-
- Asymmetric Synthesis of Both Enantiomers of Fluoxetine via Microbiological Reduction of Ethyl Benzoylacetate
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Microbiological reduction of ethyl benzoylacetate by bakers' yeast (Saccharomyces cerevisiae), Beauveria sulfurescens or Geotrichum candidum afforded ethyl (S)-3-hydroxy-3-phenylpropionate in high optical yield.This enantiomerically pure alcohol was converted into both enantiomers of fluoxetine (7).The product resulting from the bakers' yeast reduction had ee values (87-93percent) lower than the 100percent value erroneously attributed in earlier studies.Key Words: Fluoxetine; asymmetric synthesis; bioreduction; bakers' yeast; Beauveria sulfurescens; Geotrichum candidum.
- Chenevert, Robert,Fortier, Genevieve,Rhlid, Rachid Bel
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p. 6769 - 6776
(2007/10/02)
-
- Asymmetric catalysis. Production of chiral diols by enantioselective catalytic intramolecular hydrosilation of olefins
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Rhodium(I) chiral diphosphine complexes efficiently and rapidly catalyze the intramolecular hydrosilation of silyl ethers derived from allylic alcohols. The efficiency and rates of intramolecular hydrosilations were determined for a variety of silyl and olefin substituents. The catalysts were found to tolerate a wide variety of silyl substituents, although terminal alkyl olefin substituents were found to retard catalysis. Terminal aryl olefin substituents were found to be hydrosilated efficiently and at reasonable rates. One of the chiral catalysts is highly enantioselective for terminal aryl olefin substituents. Almost quantitative ee's are obtained. Moreover, the ee's are only slightly sensitive to aryl and olefin substituents, suggesting that this enantioselective catalysis can provide a wide range of chiral species. Oxidative cleavage of the hydrosilation products gives chiral diols.
- Bergens, Steven H.,Noheda, Pedro,Whelan, John,Bosnich
-
p. 2121 - 2128
(2007/10/02)
-
- Methods and compositions for treating depression using optically pure fluoxetine
-
A method and composition are disclosed utilizing the pure S(+) isomer of fluoxetine, which is a potent antidepressant substantially free of adverse toxic or psychological effects, having a rapid onset of action and a high response rate.
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- Chiral Organosilicon Compounds in Asymmetric Synthesis of Chiral 1,3-Diols
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Chiral 1,3-diols can be prepared in high enantiomeric purity (>99percent ee) from the reactions of the chiral silylcarbanion 2 with epoxides followed by oxidative cleavage of the carbon-silicon bond with hydrogen peroxide.The absolute configurations of so
- Chan, T. H.,Nwe, K. T.
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p. 6107 - 6111
(2007/10/02)
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- Efficient Synthesis of Mugineic Acid, A Typical Phytosiderophore, Utilizing the Phenyl Group as the Carboxyl Synthon
-
Stereoselective total synthesis of mugineic acid, a unique phytosiderophore from roots of barley, has been achieved from (2R,3R)- and (2S,3S)-2,3-epoxycinnamyl alcohols employing the phenyl group as the carboxyl synthon.
- Matsuura, Fumiyoshi,Hamada, Yasumasa,Shioiri, Takayuki
-
p. 7917 - 7920
(2007/10/02)
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- Chemoenzymatic Synthesis of Both Enantiomers of Fluoxetine
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Both enantiomers of fluoxetine have been synthesized from ethyl benzoylacetate.The key step is the enantioselective reduction of the starting material by baker's yeast.
- Chenevert, Robert,Fortier, Genevieve
-
p. 1603 - 1606
(2007/10/02)
-
- Asymmetric Synthesis Using Tartrate Ester Modified Allylboronates. 1. Factors Influencing Stereoselectivity
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A detailed study of the factors that influence the enantio- and diastereoselectivity of the reactions of tartrate allylboronate 1 with chiral and achiral aldehydes is reported.The stereoselectivity of these reactions is sensitive to variables such as reaction temperature (best results invariably are obtained at -78 deg C), solvent (toluene is best for aliphatic aldehydes; THF is preferred for aromatic aldehydes), and moisture (use of molecular sieves is recommended to maintain an anhydrous reaction environment), but not on the structure of the tartrate ester.Tartrate allylboronate 1 has been found to be exceptionally reactive compared to other, previously studied allylboronates, and even the reactions of very hindered substrates (e.g., pivalaldehyde) are complete within several hours at -78 deg C.An improved method for synthesis of 1 is described that involves the reaction of allylmagnesium bromide with (iPrO)3B followed by aqueous hydrolysis and esterification with DIPT.Yields of 1 are considerably higher (65-76percent) by using this new procedure, and the crude reagent so prepared may be used directly in allylboration experiments.A simple method for standardizing solutions of 1 is described.Finally, the absolute stereochemistry of five homoallylic alcohols (5a-e) were assigned by correlation with epoxy alcohols prepared via the Sharpless asymmetric epoxidation.The results of these correlations are in complete agreement with the stereochemical picture presented in our 1985 publication.
- Roush, William R.,Hoong, Lee K.,Palmer, Michelle A. J.,Park, Jae Chan
-
p. 4109 - 4117
(2007/10/02)
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- Synthesis of (aryl or arylalkyl)-3-hydroxy propionic acids and aryl alkanediols having high optical purity
-
R- and S-1-Phenyl-1,3-propanediol, each of high optical purity, were prepared by a chemoenzymatic sequence starting with ethyl benzoylacetate. The first step was a catalytic hydrogenation of the β-ketoester conducted at room temperature. The enzymatic hydrolysis of the resulting hydroxyester proceeded in a facile manner using a commercial preparation of the lipase from Pseudomonas fluorescens. The enzymatic hydrolysis proceeded at a moderate rate (350 mg lipase/0.10 mol of racemic ester required a 20-hour reaction time with an enantiomeric rate ratio (E value) of 36). The hydrolysis was run to 45-50% conversion to afford isolated S-3-phenyl-3-hydroxypropionic acid of 85-90% ee after separation from the residual ester (aqueous base extraction). The optical purity of the hydroxy acid was determined by conversion to the methyl ester (CH3 I, KHCO3, acetone), and derivatization with S-MTPA-Cl, and 1 H NMR analysis. A single recrystallization of the isolated acid afforded optically pure (>98% ee) S-3-phenyl-3-hydroxypropionic acid in an overall 36% yield from the racemic ester. The acid was reduced with borane in THF to afford optically purs S-diol in 97% yield after crystallization. The overall sequence proceeded in 34% total yield from racemic ester with an additional 45-55% recovered as the antipodal ester. This antipodal ester is obtained in 85-95% ee, and the corresponding hydroxy-acid was readily obtained (NaOH), CH3 OH/H2 O) and recrystallized to optical purity. Reduction then afforded R-1-phenyl-1,3-propanediol in 30% to overall yield from racemic ester.
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- ALDOL REACTIONS IN POLYPROPIONATE SYNTHESIS: HIGH ?-FACE SELECTIVITY OF ENOL BORINATES FROM α-CHIRAL METHYL AND ETHYL KETONES UNDER SUBSTRATE CONTROL.
-
Use of (c-C6H11)2BCl in the anti-selective aldol reaction of the α-chiral ethylketone 2 leads to high stereoselectivity (>94percent) for the 1,2-anti-2,4-anti isomer 7.The related α-chiral methylketone aldol reaction, 8 9, proceeds with 84-93percent d
- Paterson, Ian,Goodman, Jonathan M.,Isaka, Masahiko
-
p. 7121 - 7124
(2007/10/02)
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- Asymmetric Synthesis of Both Enantiomers of Tomoxetine and Fluoxetine. Selective Reduction of 2,3-Epoxycinnamyl Alcohol with Red-Al.
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Both enantiomers of tomoxetine 7a,7b and fluoxetine 8a,8b (as their hydrochloride salts) have been synthetized from cinnamyl alkohol by asymmetric epoxidation, and their absolute configurations have been established.Optimal conditions for regioselective Red-Al reduction at C-2 of 2,3-epoxycinnamyl alcohol are discussed.
- Gao, Y.,Sharpless, K. B.
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p. 4081 - 4084
(2007/10/02)
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- ELUCIDATION OF STEREOSPECIFITY OF A SELENIUM-CONTAINING HYDROGENASE FROM METHANOCOCCUS VANNIELLII - SYNTHESIS OF (R)- AND (S)--3,4-DIHYDRO-7-HYDROXY-1-HYDROXYETHYLQUINOLINE
-
To elucidate the stereospecifity of the selenium-containing hydrogenase from Methanococcus vannielii, (R)- and (S)--3,4-dihydro-7-hydroxy-1-hydroxyethylquinoline were syntheside as authentic samples for comparison with the compound which was deri
- Teshima, Tadashi,Nakaji, Akira,Shiba, Tetsuo,Tsai, Lin,Yamazaki, Shigeko
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p. 351 - 354
(2007/10/02)
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