- Chiral sulfinates studied by optical rotation, ECD and VCD: The absolute configuration of a cruciferous phytoalexin brassicanal C
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The optical rotation, electronic circular dichroism (ECD) and vibrational circular dichroism (VCD) of chiral sulfinates have been studied experimentally, and analysed by density functional theory calculation, aiming at establishing a reliable and convenie
- Taniguchi, Tohru,Monde, Kenji,Nakanishi, Koji,Berova, Nina
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- Acid catalyzed alcoholysis of sulfinamides: Unusual stereochemistry, kinetics and a question of mechanism involving sulfurane intermediates and their pseudorotation
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The synthesis of optically active sulfinic acid esters has been accomplished by the acid catalyzed alcoholysis of optically active sulfinamides. Sulfinates are formed in this reaction with a full or predominant inversion of configuration at chiral sulfur or with predominant retention of configuration. The steric course of the reaction depends mainly on the size of the dialkylamido group in the sulfinamides and of the alcohols used as nucleophilic reagents. It has been found that bulky reaction components preferentially form sulfinates with retention of configuration. It has been demonstrated that the stereochemical outcome of the reaction can be changed from inversion to retention and vice versa by adding inorganic salts to the acidic reaction medium. The unusual stereochemistry of this typical bimolecular nucleophilic substitution reaction, as confirmed by kinetic measurements, has been rationalized in terms of the addition-elimination mechanism, A-E, involving sulfuranes as intermediates which undergo pseudorotations.
- Bujnicki, Bogdan,Drabowicz, Jzef,Mikolajczyk, Marian
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p. 2949 - 2972
(2015/09/21)
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- Practical and highly stereoselective method for the preparation of several chiral arylsulfinamides and arylsulfinates based on the spontaneous crystallization of diastereomerically pure N-benzyl-N-(1-phenylethyl)- arylsulfinamides
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A novel and simple process for the preparation of enantiomerically pure (SS)-benzenesulfinamide (SS)-3a, (SS)-p- toluenesulfinamide (SS)-3b, (SS)-p-chloro- benzenesulfinamide (SS)-3c and (SS)-p- fluorobenzenesulfinamide (SS)-3d has been developed. The treatment of arylsulfinyl chlorides with (R)-N-benzyl-1-phenylethanamine in the presence of excess triethylamine gave diastereomeric mixtures of N-benzyl-N-(1-phenylethyl)- arylsulfinamides 1, which underwent spontaneous crystallization to furnish diastereomerically pure (R,SS)-N-benzyl-N-(1-phenylethyl)- arylsulfinamides (R,SS)-1a-1d in 28%, 29%, 27% and 31% yields, respectively. The diastereomerically pure compounds (R,SS)-1 were then converted into four enantiopure (RS)-methyl arylsulfinates (RS)-2, and finally into four enantiopure (SS)- arylsulfinamides (SS)-3 in good yields.
- Zhu, Rui-Heng,Shi, Xiao-Xin
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experimental part
p. 387 - 393
(2011/06/11)
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- Optical Resolution of Methyl Phenyl and Benzyl Methyl Sulfoxides and Alkyl Phenylsulfinates by Complexation with Chiral Host Compounds Derived from Tartaric Acid
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The title sulfoxides and sulfinates are resolved by complexation with chiral host compounds derived from tartaric acid.
- Toda, Fumio,Tanaka, Koichi,Okada, Toru
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p. 639 - 640
(2007/10/02)
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- Asymmetric synthesis of chiral organosulfur compounds using N-sulfinyloxazolidinones
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This paper describes a new class of chiral sulfinyl transfer reagents, 4 and 5 (R = aryl, alkyl), which are readily prepared from the oxazolidinones derived from (4R,5S)-norephedrine (HXN) and (4S)-phenylalanine (HXp), respectively. These N-suIfinyloxazolidinone reagents can be synthesized either by sulfinylation-of the metalated oxazolidinones or by oxidation of the derived N-sulfenimides to afford the diastereomeric N-sulfinyloxazolidinones which may be readily purified by chromatography. These sulfinylating agents react with a wide range of nucleophiles such as Grignard reagents, enolates, lithium alkoxides, or metalated amides, with inversion of configuration at the sulfur center to afford the derived chiral sulfoxides, sulfinate esters, and sulfinamides in high yields and enantioselectivities. Competition experiments have established that this family of chiral sulfinylating agents is at least 100 times as reactive as the corresponding menthyl sulfinate esters toward Grignard reagents.
- Evans, David A.,Faul, Margaret M.,Colombo, Lino,Bisaha, John J.,Clardy, Jon,Cherry, David
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p. 5977 - 5985
(2007/10/02)
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- NUCLEOPHILIC SUBSTITUTION AT SULFINYL AND SULFONYL CENTRES: STEREOCHEMICAL AND KINETIC STUDIES
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The mechanism and stereochemistry of nucleophilic substitution reactions at sulfur (SN-S) are discussed in the light of experimental results obtained in the author's laboratory.The first part of this short review article is devoted to the acid-catalyzed alcoholysis of chiral sulfinates and sulfinamides.In the second part, the results of kinetic studies of the isotopic chloride-chloride exchange reaction in sulfonyl chlorides are presented.
- Mikolajczyk, Marian
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