- Chiral Ligands in Hypervalent Iodine Compounds: Synthesis and Structures of Binaphthyl-Based λ3-Iodanes
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Several novel binaphthyl-based chiral hypervalent iodine(III) reagents have been prepared and structurally analysed. Various asymmetric oxidative reactions were applied to evaluate the reactivities and stereoselectivities of those reagents. Moderate to excellent yields were observed; however, very low stereoselectivities were obtained. NMR experiments indicated that these reagents are very easily hydrolysed in either chloroform or DMSO solvents leading to the limited stereoselectivities. It is concluded that the use of chiral ligands is an unsuccessful way to prepare efficient stereoselective iodine(III) reagents.
- Zhang, Huaiyuan,Cormanich, Rodrigo A.,Wirth, Thomas
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supporting information
(2021/12/22)
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- Localized Partitioning of Enantiomers in Solid Samples of Sulfoxides: Importance of Sampling Method in Determination of Enantiopurity
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Localized partitioning of amorphous enantioenriched aryl benzyl sulfoxides in the solid state can lead to substantial variation in enantiopurities, even for sulfoxides which do not show detectable levels of self-disproportionation of enantiomers (SDE) dur
- Flynn, Aaran J.,Ford, Alan,Maguire, Anita R.
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p. 10216 - 10221
(2020/09/09)
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- Palladium/PC-Phos-Catalyzed Enantioselective Arylation of General Sulfenate Anions: Scope and Synthetic Applications
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Herein we reported an efficient palladium-catalyzed enantioselective arylation of both alkyl and aryl sulfenate anions to deliver various chiral sulfoxides in good yields (up to 98%) with excellent enantioselectivities (up to 99% ee) by the use of our developed chiral O,P-ligands (PC-Phos). PC-Phos are easily prepared in short steps from inexpensive commercially available starting materials. The single-crystal structure of the PC4/PdCl2 showed that a rarely observed 11-membered ring was formed via the O,P-coordination with the palladium(II) center. The salient features of this method include general substrate scope, ease of scale-up, applicable to the late-stage modification of bioactive compounds, and the synthesis of a marketed medicine Sulindac.
- Wang, Lei,Chen, Mingjie,Zhang, Peichao,Li, Wenbo,Zhang, Junliang
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p. 3467 - 3473
(2018/03/13)
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- Method for preparing chiral sulfoxide through catalysis of asymmetric oxidation of thioether
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The invention provides a method for preparing chiral sulfoxide. According to the method, in a mixed solvent, thioether is used as a substrate, a complex produced by chiral tetradentate organic ligand and a metal manganese compound in situ is used as a cat
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Paragraph 0058; 0059; 0060; 0061; 0063
(2016/10/10)
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- Development of a Continuous-Flow Microreactor for Asymmetric Sulfoxidation Using a Biomimetic Manganese Catalyst
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Asymmetric sulfoxidation catalyzed by a biomimetic manganese complex under continuous-flow microreactor is described. The reaction is conducted in microreactor, it can rapidly (4 min) oxidize a wide scope of sulfides with high yield (up to 91%) and excel
- Dai, Wen,Mi, Yuan,Lv, Ying,Chen, Bo,Li, Guosong,Chen, Guangwen,Gao, Shuang
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p. 667 - 671
(2016/02/27)
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- Enantioselective oxidation of sulfides with H2O2 catalyzed by a pre-formed manganese complex
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A facile and environmentally friendly method is presented for the asymmetric oxidation of sulfides with H2O2, utilizing a pre-formed manganese complex. Just in the presence of a low catalytic amount of carboxylic acid (CA), a variety of sulfide substrates, including aryl alkyl, aryl benzyl and cyclic sulfides, reacted to form chiral sulfoxides in high yields (up to 95%) and excellent enantioselectivities (>99% ee) under mild conditions. Moreover, the practical utility of the method has been demonstrated by the synthesis of esomeprazole and albendazole sulfoxide (ABZO).
- Dai, Wen,Li, Guosong,Wang, Lianyue,Chen, Bo,Shang, Sensen,Lv, Ying,Gao, Shuang
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p. 46545 - 46554
(2014/12/10)
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- Asymmetric oxidation catalysis by a porphyrin-inspired manganese complex: Highly enantioselective sulfoxidation with a wide substrate scope
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The first genuinely promising porphyrin-inspired manganese-catalyzed asymmetric sulfoxidation method using hydrogen peroxide has been successfully developed, allowing for rapidly oxidizing (0.5-1.0 h) a wide variety of sulfides in high yields with excellent enantioselectivities (up to >99% ee).
- Dai, Wen,Li, Jun,Chen, Bo,Li, Guosong,Lv, Ying,Wang, Lianyue,Gao, Shuang
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supporting information
p. 5658 - 5661
(2013/12/04)
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- Investigation of steric and electronic effects in the copper-catalysed asymmetric oxidation of sulfides
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Steric and electronic effects in the copper-catalysed asymmetric oxidation of aryl benzyl, aryl alkyl and alkyl benzyl sulfides have been investigated. The presence of an aryl group directly attached to the sulfur is essential to afford sulfoxides with high enantioselectivities, with up to 97% ee for 2-naphthyl benzyl sulfoxide, the highest enantioselectivity achieved to date for copper-catalysed asymmetric sulfoxidation. In contrast, the benzyl substituent can be replaced by sterically comparable groups with no effect on enantioselectivity. Copper-mediated oxidation of substituted aryl benzyl sulfides display modest steric and electronic effects resulting in comparable or lower enantioselectivities to those obtained with the unsubstituted benzyl phenyl sulfide.
- O'Mahony, Graham E.,Eccles, Kevin S.,Morrison, Robin E.,Ford, Alan,Lawrence, Simon E.,Maguire, Anita R.
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supporting information
p. 10168 - 10184
(2013/11/06)
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- A new methodology for the oxidation of sulfides with Fe(III) catalysts
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A variety of sulfides were converted to the corresponding sulfoxide derivatives with 70% t-BuOOH (water) as the oxidant in the presence of catalytic quantity of Fe2(SO4)3. The method described has a wide range of applicati
- Chakraborty, Debashis,Malik, Payal,Goda, Vinod Kumar
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experimental part
p. 21 - 26
(2012/03/11)
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- Copper-catalyzed asymmetric oxidation of sulfides
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Copper-catalyzed asymmetric sulfoxidation of aryl benzyl and aryl alkyl sulfides, using aqueous hydrogen peroxide as the oxidant, has been investigated. A relationship between the steric effects of the sulfide substituents and the enantioselectivity of th
- O'Mahony, Graham E.,Ford, Alan,Maguire, Anita R.
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experimental part
p. 3288 - 3296
(2012/05/20)
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- Organocatalytic asymmetric synthesis of sulfoxides from sulfenic acid anions mediated by a cinchona -derived phase-transfer reagent
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Preliminary results concerning a conceptually novel route to chiral sulfoxides based on the asymmetric alkylation of sulfenate salts with alkyl halides mediated by a chiral phase-transfer catalyst are described. As a representative example, o-anisyl methyl sulfoxide was produced in 96% yield and with an enantiomeric excess of 58% using commercial cinchonidinium derivative 2a.
- Gelat, Fabien,Jayashankaran, Jayadevan,Lohier, Jean-Francois,Gaumont, Annie-Claude,Perrio, Stephane
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p. 3170 - 3173
(2011/08/06)
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- Catalytic enantioselective oxidation of bulky alkyl aryl thioethers with H2O2 over titanium-salan catalysts
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A simple and efficient catalytic procedure for the oxidation of bulky (preferably aryl benzyl substituted) thioethers with hydrogen peroxide in good to high yields and enantioselectivities (up to 98.5%ee) is reported. The high optical yields are achieved in a tandem stereoconvergent enantioselective oxidation and kinetic resolution process. A reasonable balance between the sulfoxide yield and enantioselectivity could be found by varying the concentration and temperature. An improved synthesis of the titanium-salan catalysts for the preparation of a more stereoselective catalyst is reported.
- Bryliakov, Konstantin P.,Talsi, Evgenii P.
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experimental part
p. 4693 - 4698
(2011/10/03)
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- Stereoselective control by face-to-face versus edge-to-face aromatic interactions: The case of C3-TiIV amino trialkolate sulfoxidation catalysts
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The stereoselective oxidation of differently functionalised benzyl phenyl sulfides has been examined by using enantiopure TiIV trialkanolamine complexes. These complexes efficiently catalyse the sulfoxidation with good stereoselectivities. The
- Santoni, Gabriella,Mba, Miriam,Bonchio, Marcella,Nugent, William A.,Zonta, Cristiano,Licini, Giulia
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supporting information; scheme or table
p. 645 - 654
(2010/05/18)
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- Synthesis of optically active 2,5-dialkylcyclohexane-1,4-diols and their application in the asymmetric oxidation of sulfides
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A simple and efficient approach to obtain optically pure 1,4-diols was established. The asymmetric oxidation of sulfides to sulfoxides with cumyl hydroperoxide in moderate yields and moderate to high enantioselectivities (up to 84%) catalyzed by chiral Ti/ 1,4-diols complexes has been achieved. A 76% ee value was obtained in the asymmetric synthesis of esomeprazole. Georg Thieme Verlag Stuttgart.
- Sun, Jiangtao,Yang, Minghua,Dai, Zhenya,Zhu, Chengjian,Hu, Hongwen
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scheme or table
p. 2513 - 2518
(2009/04/11)
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- Enantioselective sulfoxidation and kinetic resolution combined protocol mediated by a functionalized (S)-norcamphor-based hydroperoxide/titanium(IV) isopropoxide system
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A functionalized tertiary furyl hydroperoxide derived from (S)-norcamphor has been easily synthesized in good yield and in a highly diastereoselective manner. Good to high enantioselectivities (up to 99% ee) and acceptable to good yields (up to 86%) were achieved for the sulfoxides, by tandem stereoconvergent asymmetric sulfoxidation and kinetic resolution when using the novel hydroperoxide s oxygen donor and chirality source in the presence of catalytic loadings of titanium(IV) isopropoxide as the catalyst.
- Lattanzi, Alessandra,Piccirillo, Sandro,Scettri, Arrigo
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p. 357 - 363
(2008/02/07)
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- Asymmetric synthesis of aryl benzyl sulfoxides by vanadium-catalysed oxidation: A combination of enantioselective sulfide oxidation and kinetic resolution in sulfoxide oxidation
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Enantioselective vanadium-catalysed oxidation of aryl benzyl sulfides using Bolm's procedure is accompanied by kinetic resolution in the oxidation of the resulting sulfoxides which enhances the enantiopurities of the sulfoxides recovered (typically >90% ee), albeit with an associated reduction in yield. The effects of ligand, solvent and reaction conditions are discussed in detail. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.
- Kelly, Padraig,Lawrence, Simon E.,Maguire, Anita R.
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p. 4500 - 4509
(2007/10/03)
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- Kinetic resolution in vanadium-catalyzed sulfur oxidation as an efficient route to enantiopure aryl benzyl sulfoxides
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Enantiopure aryl benzyl sulfoxides can be prepared using vanadium-Schiff base catalyzed sulfide oxidation and kinetic resolution of the resulting sulfoxide. The kinetic resolution can be effected in combination with asymmetric sulfide oxidation or instead starting from the racemic sulfoxide. Georg Thieme Verlag Stuttgart.
- Kelly, Pádraig,Lawrence, Simon E.,Maguire, Anita R.
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p. 1569 - 1573
(2007/10/03)
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- Palladium-catalyzed reaction of boronic acids with chiral and racemic α-bromo sulfoxides
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Palladium-catalyzed cross-coupling reactions of racemic α-bromo sulfoxides with boronic acids are carried out in either aqueous or nonaqueous medium with formation of a new C sp3-C sp2 bond. The arylation of chiral α-bromo sulfoxides occurs without racemization. The cross-coupling reaction is general and gives high yields with arylboronic acids substituted with either donor or acceptor groups but gives poor results with heteroarylboronic acids. The best yields are obtained using degassed solvents and CsF instead of aqueous base. The use of aqueous base and the presence of oxygen favor the homocoupling side reaction.
- Rodriguez, Nuria,Cuenca, Ana,Ramirez De Arellano, Carmen,Medio-Simon, Mercedes,Peine, Denissa,Asensio, Gregorio
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p. 8070 - 8076
(2007/10/03)
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- Efficient asymmetric oxidation of sulfides and kinetic resolution of sulfoxides catalyzed by a vanadium-salan system
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The asymmetric oxidation of sulfides to chiral sulfoxides with hydrogen peroxide in good yield and high enantioselectivity has been catalyzed very effectively by chiral vanadium-salan [N,N′-alkyl bis(salicylamine)] complex. The salan ligand shows results superior in terms of reactivity and enantioselectivity to those of salen [N,N′-alkylene bis(salicylideneimine) ] analogue, and provides the sulfoxide with opposite configuration. The high enantioselectivity of this reaction is the direct result of the asymmetric oxidation. The efficient kinetic resolution of racemic sulfoxides catalyzed by the vanadium-salan system is also described.
- Sun, Jiangtao,Zhu, Chengjian,Dai, Zhenya,Yang, Minghua,Pan, Yi,Hu, Hongwen
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p. 8500 - 8503
(2007/10/03)
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- Enantioselective oxidation of sulfides with hydrogen peroxide catalyzed by vanadium complex of sterically hindered chiral Schiff bases
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Sterically hindered chiral Schiff base ligands 4a-d were prepared from an aldehyde derived from BINOL. The vanadium complexes of the ligands catalyze an efficient, enantioselective H2O2-promoted sulfoxidation of alkyl aryl sulfides, and enantioselectivities as high as 98-99% ee are observed in the sulfoxidation of benzyl aryl sulfides.
- Jeong, Yong-Chul,Choi, Soojin,Hwang, Yao Dong,Ahn, Kwang-Hyun
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p. 9249 - 9252
(2007/10/03)
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- WO3-30% H2O2-cinchona alkaloids: A new heterogeneous catalytic system for the asymmetric oxidation of sulfides and the kinetic resolution of racemic sulfoxides
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WO3-catalyzed asymmetric oxidation of thioethers and kinetic resolution of sulfoxides with 30% aq. H2O2 in the presence of cinchona alkaloids under heterogeneous conditions affords chiral sulfoxides in high yields with moderate to good enantioselectivities.
- Thakur, Vinay V.,Sudalai
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p. 407 - 410
(2007/10/03)
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- Catalytic asymmetric oxidation of aryl sulfides with a Ti/H2O/(R,R)- diphenylethane-1,2-diol complex: A versatile and highly enantioselective oxidation protocol
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A new catalytic procedure for the asymmetric oxidation of aryl alkyl and aryl benzyl sulfides to optically active sulfoxides by hydroperoxides is described. This oxidation of sulfides is mediated by a chiral Ti complex formed in situ by reacting Ti(i-PrO)4, (R,R)-diphenylethane-1,2-diol (1), and water. The conditions of the reaction (stoichiometric composition of the catalyst, temperature, and the presence of additives and solvent) have been determined in order to reach the highest enantioselectivity and avoid the intervention of a kinetic resolution process. The oxidation protocol described herein is quite versatile as the values of chemical yields (60- 73%) and of enantioselectivity (ee 70-80%) achieved for aryl alkyl sulfides are almost independent of the nature of the aryl substituent and of the size of the alkyl group. Notably, aryl benzyl sulfides, which are poor substrates for the Ti/DET catalyzed oxidations, afforded very high ee's (92-99%) with this oxidation system.
- Donnoli, Maria Irene,Superchi, Stefano,Rosini, Carlo
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p. 9392 - 9395
(2007/10/03)
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- Asymmetric synthesis of chiral sulfoxides and sulfinimines by using N-sulfinylsultam
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Bornane-10,2-sultam 1 is stereoselectively converted by DMAP-assisted sulfinylation to diastereomerically pure (2R)-N-[(R)-p-tolylsulfinyl]-bornane-10,2-sultam 2 in 77% yield. The crystalline sulfinylating agent 2 reacts with a variety of nucleophiles to afford sulfoxides 3 and sulfinimines 5 in excellent yields and enantioselectivities.
- Oppolzer, Wolfgang,Froelich, Olivier,Wiaux-Zamar, Chantal,Bernardinelli, Gerald
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p. 2825 - 2828
(2007/10/03)
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- Hypervalent iodine in synthesis. XXIII: Oxidation with [hydroxy(tosyloxy)iodo]benzene: Selective oxidation of sulfides to sulfoxides
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Alkyl- and aryl-sulfides can be selectively oxidated to their corresponding sulfoxides with excellent yields under mild conditions by [hydroxy(tosyloxy)iodo]benzene. Moreover, [hydroxy (((+)-10-camphorosulfonyl)oxy)iodo]benzene as the chiral oxidizer, can
- Xia, Min,Chen, Zhen-Chu
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p. 1315 - 1320
(2007/10/03)
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- Chemistry of oxaziridines. 17. N-(phenylsulfonyl)(3,3-dichlorocamphoryl)oxaziridine: A highly efficient reagent for the asymmetric oxidation of sulfides to sulfoxides
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The synthesis, structure, and enantioselective oxidations of a new chiral N-sulfonyloxaziridine 12c [3,3-dichloro-1,7,7-trimethyl-2'-(phenylsulfonyl)spiro[bicyclo[2.2.1]heptane-2, 3'-oxaziridine]] are reported. This oxidant, which exhibits remarkably high and predictable ee's for the enantioselective oxidation of prochiral sulfides to sulfoxides, is prepared in three steps from (+)- or (-)-camphor in 50% overall yield. Steric effects are primarily responsible for the molecular recognition and are predictable using a simple active-site model where the nonbonded interactions between the RL and RS groups of the sulfide (RL-S-RS) and the active-site surface are minimized in a planar transition-state structure. The fact that alkyl aryl sulfides give high ee's in nonpolar solvents suggests that there is also a stereoelectronic component to the molecular recognition. High ee's (>90%) are anticipated for those sulfides where the difference in size of the groups directly bonded to the sulfur atom is large, i.e., aryl, tert-butyl vs CH2R (R = H, alkyl, benzyl, etc). The X-ray structure and studies with the dihydro, difluoro, and dibromo oxaziridines 12a, 12b, and 12d reveal that the exceptional enantioselectivities displayed by 12c are a consequence of a molecular cleft or groove, defined by the oxaziridine chlorine atoms and phenylsulfonyl group, on the active-site surface.
- Davis, Franklin A.,Thimma Reddy,Han, Wei,Carroll, Patrick J.
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p. 1428 - 1437
(2007/10/02)
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- Microbial oxidation of benzyl sulfides and bibenzyl by Mortierella isabellina and Helminthosporium species
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The biotransformation of 1,2-diphenylethane by the fungus Mortierella isabellina ATCC 42613, and that of a series of alkyl benzyl sulfides by the fungi M. isabellina and Helminthosporium species NRRL 4671 have been studied.Mortierella hydroxylates 1,2-diphenylethane in low yield, giving (S)-1,2-diphenylethanol with an enantiomeric purity of 33percent.Bioconversions of deuterium-labelled and racemic 1,2-diphenylethanol by M. isabellina demonstrate that this organism performs reversible oxidation/reduction of the alcohol.Biotransformations of n-alkyl benzyl sulfides by H. species give predominatly the (S) enantiomer of sulfoxide, with no sulfone formation, but M. isabellina, although showing a general preference for the oxidation of alkyl benzyl sulfides to (R) sulfoxides, also generates sulfones from n-alkyl benzyl sulfides in a time-dependent manner that suggests a stereoselective removal of (R) sulfoxide.The latter microorganism can be used, however, for the production of (R)-benzyl methyl and benzyl isopropyl sulfoxides, and gives (S)-benzyl tert-butyl sulfoxide in low yield. Key words: biotransformation, enzymes, sulfoxides.
- Holland, Herbert L.,Rand, Cynthia G.,Viski, Peter,Brown, Frances M.
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p. 1989 - 1993
(2007/10/02)
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- AN EFFICIENT 1,3-ASYMMETRIC INDUCTION ACCOMPANIED WITH EPIMERIZATION AT THE 2-POSITION. STEREOSELECTIVE REDUCTION OF α-SUBSTITUTED β-KETO SULFOXIDES UNDER BASIC CONDITIONS
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An efficient 1,3-asymmetric induction was realized in the reduction of β-keto sulfoxides having various α-substituents with NaBH4 under basic conditions and, by the application of this induction, (R)-α-acetoxyphenylacetaldehyde was synthesized.
- Ogura, Katsuyuki,Fujita, Makoto,Inaba, Takashi,Takahashi, Kazumasa,Iida, Hirotada
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p. 503 - 506
(2007/10/02)
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- Kinetic Resolution of Sulphoxides by Chiral Poly(N-Alkyliminoalanes)
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Kinetic resolution of racemic sulphoxides by chiral poly (PIA-PHETs) from (+) - or (-)-1-phenylethylamine is described.For p-tolyl mesityl sulphoxide in the temperature range between -25 and 85 deg C, optical yields increase with temperature to an upper limit of between 55 and 70 deg C, with enantiomeric enrichments up to 75percent.It is shown that, among the three molecular species of PIA-PHET (closed-cage tetramer, closed-cage hexamer and open-cage tetramer), only the last is chemically active and capable of chiral recognition.Reactions follow second-order kinetics (first-order in sulphoxide, first-order in open PIA-PHET tetramer).The particular molecular structure of the latter probably accounts for the high degree of chiral recognition at high temperature.
- Annunziata, Rita,Borgogno, Guido,Montanari, Fernando,Quici, Silvio,Cucinella, Salvatore
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p. 113 - 118
(2007/10/02)
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