Properly Designed Modular Asymmetric Synthesis for Enantiopure Sulfinamide Auxiliaries from <i>N</i>-Sulfonyl-1,2,3-oxathiazolidine-2-oxide Agents

Han, Zhengxu S.; Krishnamurthy, Dhileepkumar; Grover, Paul; Fang, Q. Kevin; Senanayake, Chris H.

doi:10.1021/ja0200692

Cited by 119 publications

(71 citation statements)

References 12 publications

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“…262 Ephedrine 232, which had been used by Wudl and Lee was replaced by (1R, 2S)-(+)-cis-amino-2-indanol, 236. Following the procedure outlined in (Scheme 118), high enantioselectivity and high yields were reported for the preparation of sulfinamides.…”

Section: Scheme 117mentioning

confidence: 99%

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Synthesis of enantioenriched sulfoxides

O’Mahony¹,

Kelly²,

Lawrence³

et al. 2011

Arkivoc

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This review discusses strategies for the asymmetric synthesis of sulfoxides, compounds with many applications in stereoselective synthesis and in some cases with pharmaceutical application. The review describes asymmetric oxidation, including metal catalyzed and nonmetal and biological oxidation processes, in addition to synthetic approaches via nucleophilic substitution of appropriately substituted precursors. Kinetic resolution in oxidation of sulfoxides to the analogous sulfones is also discussed; in certain instances, access to enantioenriched sulfoxides can be achieved via a combination of asymmetric sulfide oxidation and complementary kinetic resolution in sulfoxide oxidation.

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Section: Scheme 117mentioning

confidence: 99%

“…[262][263] The method is very similar to that used to prepare sulfinamides shown in Scheme 118. Senanayake initially synthesised sulfoxides using N-sulfonyl-1,2,3-oxathiazolidine-2-oxide 237 endo and 237 exo where R = para-tolyl or 2,4,6-mesityl (Scheme 119).…”

Section: Scheme 118mentioning

confidence: 99%

Synthesis of enantioenriched sulfoxides

O’Mahony¹,

Kelly²,

Lawrence³

et al. 2011

Arkivoc

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“…The chiral N-sulfinyl imines 1, 4, and 5 were prepared by condensing the corresponding aldehyde and sulfinamide 23,38,39) according to known procedures. …”

Section: Preparation Of Chiral Iminesmentioning

confidence: 99%

Stereoselective Radical Addition of an Acetal to Sterically Tuned Enantiomerically Pure N-Sulfinyl Imines

Akindele

Yamada

Sejima

et al. 2010

CHEMICAL & PHARMACEUTICAL BULLETIN

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NotesGiven the ubiquitous nature of the C-N stereogenic center, efficient synthetic methods continue to be developed for its installation in both simple and complex chemical structures.1-3) These methods could be broadly classified into reactions mediated by ionic or radical species. Majority of these methods are mediated by ionic species, requiring highly basic reagents which limit the substrate scope of these approaches, albeit the products are obtained in high yield and enantioselectivity. On the other hand, methods involving radical species 4,5) are relatively under explored despite the potential of this approach to deliver much more structurally varied products using milder reagents.To date, the lack of a catalytic asymmetric radical addition method to N-sulfonyl imines 6,7) has made the use of chiral Nsulfinyl imines as radical acceptors, for creating predictable stereodefined C-N stereogenic centers in sulfonamides, an appealing alternative synthetic strategy. Indeed, the pioneering works of Davis and Ellman on the synthesis and reactivity of N-sulfinyl imines have given the synthetic community a readily available and robust precursor of optically active amine compounds. [8][9][10][11][12][13][14][15][16] Due to this rarity of radical species-mediated methods as well as our ongoing interest in radical reactions, [17][18][19] we sought to improve the efficiency and substrate scope of our initial report on radical addition of ethers and acetals to enantiopure N-p-toluenesulfinyl aldimines. 20) In this previous report, an in-house dimethylzinc-air radical initiator was used to generate carbon-centered a-alkoxyalkyl radicals from ethers and acetals. Subsequent nucleophilic addition of the radicals to the enantiopure N-sulfinyl imines followed by oxidation afforded the sulfonamide adducts in enantiomerically enriched forms. It is noteworthy that boron trifluoride diethyl etherate was essential for faster reaction rate while a sterically hindered acetal was crucial to good stereocontrol (Chart 1).Subsequent investigations have led to improved levels of stereocontrol. Herein, we detail our new findings along with a computational rationale for the improved levels of stereocontrol. Results and DiscussionAs we previously reported, 20) the reaction of (S)-Nbenzylidene-4-toluenesulfinamide (1a) with acetal 2 21) proceeded smoothly in the presence of trifluoroborane diethyl etherate using dimethylzinc-air to give a crude mixture including sulfinamide products 6a with a 9 : 1 diastereomeric ratio along with a trace amount of sulfonamide product 3a (ca. 1%). Subsequent oxidation of the crude products with m-chloroperbenzoic acid (m-CPBA) provided 3a with 80% ee in 92% yield (Table 1, entry 1). The enantiomeric ratio of 3a was the same as the diastereomeric ratio of 6a in the crude mixture, showing that no racemization took place during the m-CPBA oxidation.We reasoned that by substituting a bulkier group for the ptolyl group on the sulfur stereogenic center would presumably lead to higher levels of stereocontrol. In fac...

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“…Chiral sulfites, [9] aminosulfites [10][11][12] and sulfinamides [13] have been used instead of sulfinates as precursors of sulfoxides in Andersen-type methodology. The sulfinyl group can act as an ortho-directing group in deprotonation reactions by LDA, for example.…”

Section: Introductionmentioning

confidence: 99%

Metallocene Sulfoxides as Precursors of Metallocenes with Planar Chirality

Ferber

Kagan

2007

Adv Synth Catal

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The preparation of metallocene sulfoxides and their ortho-diastereoselective functionalization are described. The applications of enantiopure 1,2-and 1,3-disubstituted metallocenes are reviewed, with special emphasis on the preparation of ligands for asymmetric catalysis. The sulfoxide functionality is a useful, traceless, chiral diastereoselective orthodirecting group, as explained in the article. It allows one to synthesize a wide range of enantiopure metallocenes with planar chirality and predictible configuration. Most of the examples are related to the ferrocene area.

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Properly Designed Modular Asymmetric Synthesis for Enantiopure Sulfinamide Auxiliaries from N-Sulfonyl-1,2,3-oxathiazolidine-2-oxide Agents

Cited by 119 publications

References 12 publications

Synthesis of enantioenriched sulfoxides

Synthesis of enantioenriched sulfoxides

Stereoselective Radical Addition of an Acetal to Sterically Tuned Enantiomerically Pure N-Sulfinyl Imines

Metallocene Sulfoxides as Precursors of Metallocenes with Planar Chirality

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