84413-66-1Relevant articles and documents
Chemoenzymatic Deracemization of Chiral Sulfoxides
Nosek, Vladimír,Mí?ek, Ji?í
supporting information, p. 9849 - 9852 (2018/07/31)
The highly enantioselective enzyme methionine sulfoxide reductase A was combined with an oxaziridine-type oxidant in a biphasic setup for the deracemization of chiral sulfoxides. Remarkably, high ee values were observed with a wide range of substrates, thus providing a practical route for the synthesis of enantiomerically pure sulfoxides.
HPLC enantioseparation on a homochiral MOF-silica composite as a novel chiral stationary phase
Tanaka, Koichi,Muraoka, Toshihide,Otubo, Yasuhiro,Takahashi, Hiroki,Ohnishi, Atsushi
, p. 21293 - 21301 (2016/03/08)
The last frontier in the development of chiral stationary phases for chromatographic enantioseparation involves homochiral metal-organic frameworks (MOFs). Using enantiopure (R)-2,2′-dihydroxy-1,1′-binaphthalene-6,6′-dicarboxylic acid as a starting material, we prepared three homochiral MOFs that were further used as chiral stationary phases for high-performance liquid chromatography to separate the enantiomers of various kinds of racemic sulfoxides, sec-alcohols, β-lactams, benzoins, flavanones and epoxides. The experimental results showed excellent performances for enantioseparation, and highlighted that enantioseparation on homochiral MOF columns is practical.
Efficient HPLC enantiomer separation using a pillared homochiral metal-organic framework as a novel chiral stationary phase
Tanaka, Koichi,Hotta, Naoki,Nagase, Shohei,Yoza, Kenji
supporting information, p. 4891 - 4894 (2016/07/06)
HPLC enantioseparation of racemates using novel pillared homochiral metal-organic framework-silica composite as chiral stationary phase has been successfully demonstrated.
Iron-catalyzed imidative kinetic resolution of racemic sulfoxides
Wang, Jun,Frings, Marcus,Bolm, Carsten
supporting information, p. 966 - 969 (2014/02/14)
Kinetic resolution of racemic sulfoxides requires either custom substrates or shows moderate enantioselectivity, leading to achiral coproducts (such as sulfones) as an intrinsic part of the process. A new strategy is demonstrated that allows the resolution of racemic sulfoxides through catalytic asymmetric nitrene-transfer reactions. This approach gives rise to both optically active sulfoxides and highly enantioenriched sulfoximines. By using a chiral iron catalyst and a readily available iodinane reagent, high selectivity factors have been achieved under very practical reaction conditions. With respect to the substrate scope, it is noteworthy that this unprecedented imidative kinetic resolution of racemic sulfoxides provides access to both aryl-alkyl and dialkyl sulfoximines in highly enantioenriched forms. Copyright
Predominant (S)-enantioselective inclusion of aryl methyl sulfoxides by (S)-isoleucyl-(S)-phenylglycines
Akazome, Motohiro,Doba, Ai,Matsumoto, Shoji,Ogura, Katsuyuki
supporting information; experimental part, p. 660 - 665 (2010/04/26)
(Figure Presented) In terms of chiral recognition for racemic aryl methyl sulfoxides in the solid state, three kinds of crystalline (S)-alkylglycyl-(S)- phenylglycines were examined as potential dipeptides host molecules. When (S)-alanyl-(S)-phenylglycines [(S,S)-Ala-Phg] crystallized with aryl methyl sulfoxides, the stereochemistry of preferentially included sulfoxides depended on the individual shapes of the sulfoxides and the enantiomeric excess was relatively low. Although (S)-leucyl-(S)-phenylglycines [(S,S)-Leu-Phg] and (S)-isoleucyl-(S)-phenylglycines [(S,S)-Ile-Phg] mainly included the S-form of aryl methyl sulfoxides, the enantiomeric recognition of (S,S)-Ile-Phg was superior to that of (S,S)-Leu-Phg. Single-crystal X-ray analysis of these inclusion compounds revealed that the dipeptide molecules self-assembled to form layer structures and included sulfoxides between these layers through hydrogen bonding between the proton of +NH3 and the oxygen of the sulfoxide. Besides these host-guest interactions, the phenyl groups of the sulfoxides interacted with each other through the phenyl-phenyl interaction. Two adjacent homochiral sulfoxides make a pair having a 2-fold screw axis along the channel cavity. Thus, the self-recognition of sulfoxides made 21 helical column structures and had high enantioselectivity.
Development and application of versatile bis-hydroxamic acids for catalytic asymmetric oxidation
Barlan, Allan U.,Zhang, Wei,Yamamoto, Hisashi
, p. 6075 - 6087 (2008/02/03)
In this article, we describe the development and preliminary results of our new designed C2-symmetric bis-hydroxamic acid (BHA) ligands and the application of the new ligands for vanadium-catalyzed asymmetric epoxidation of allylic alcohols as well as homoallylic alcohols. From this success we demonstrate the versatile nature of BHA in the molybdenum catalyzed asymmetric oxidation of unfunctionalized olefins and sulfides.
Highly enantioselective oxidation of sulfides to sulfoxides by a new oxaziridinium salt
Del Rio,Wang,Achab,Bohe
, p. 2265 - 2268 (2008/02/04)
The new oxaziridinium salt 5 (R2 = TBDPS) is an effective reagent for the highly enantioselective oxidation of sulfides to sulfoxides with up to >99% ee and good yields. As such, it represents a new valuable nonmetallic alternative to the existing methods for asymmetric sulfoxidation.
Catalytic enantioselective oxidation of sulfides and disulfides by a chiral complex of bis-hydroxamic acid and molybdenum
Basak, Arindrajit,Barlan, Allan U.,Yamamoto, Hisashi
, p. 508 - 511 (2007/10/03)
A chiral bis-hydroxamic acid (BHA)-molybdenum complex was used for the catalytic asymmetric oxidation of sulfides and disulfides utilizing one equivalent of alkyl peroxide with yields up to 83% and ee up to 86%. An extension of our methodology combines the asymmetric oxidation with kinetic resolution providing excellent enantioselectivity (ee 92-99%).
Chiral ionic liquids as stationary phases in gas chromatography
Ding, Jie,Welton, Thomas,Armstrong, Daniel W.
, p. 6819 - 6822 (2007/10/03)
Recently, it has been found that room-temperature ionic liquids can be used as stable, unusual selectivity stationary phases. They show "dual nature" properties, in that they separate nonpolar compounds as if they are nonpolar stationary phases and separate polar compounds as if they are polar stationary phases. Extending ionic liquids to the realm of chiral separations can be done in two ways: (1) a chiral selector can be dissolved in an achiral ionic liquid, or (2) the ionic liquid itself can be chiral. There is a single precedent for the first approach, but nothing has been reported for the second approach. In this work, we present the first enantiomeric separations using chiral ionic liquid stationary phases in gas chromatography. Compounds that have been separated using these ionic liquid chiral selectors include alcohols, diols, sulfoxides, epoxides, and acetylated amines. Because of the synthetic nature of these chiral selectors, the configuration of the stereogenic center can be controlled and altered for mechanistic studies and reversing enantiomeric retention.
Novel catalytic asymmetric sulfoxidation in water using the hypervalent iodine reagent iodoxybenzene
Tohma, Hirofumi,Takizawa, Shinobu,Morioka, Hironori,Maegawa, Tomohiro,Kita, Yasuyuki
, p. 445 - 446 (2007/10/03)
A new catalytic asymmetric oxidation of sulfides to sulfoxides in water using the hypervalent iodine(V) reagent iodoxybenzene (PhIO2) has been developed. This methodology is distinctly different from the previously reported use of cyclodextrins or biological catalysts and provides a new route to asymmetric sulfoxidation in water.