A Convenient Method for the Synthesis of 2-Arylaziridines from Styrene Derivatives via 2-Arylethenyl(diphenyl)sulfonium Salts

Matsuo, Jun‐ichi; Yamanaka, Hiroyuki; Kawana, Asahi; Mukaiyama, Teruaki

doi:10.1246/cl.2003.392

Cited by 64 publications

(18 citation statements)

References 11 publications

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“…We have previously reported that diphenyl sulfide bis(trifluoromethanesulfonate) reacts with styrene to generate the corresponding active sulfonium intermediate, which in turn reacts with amines to afford aziridines or b,g-unsaturated amines. 12,13) Therefore, formation of an alkoxy diphenyl sulfonium intermediate was anticipated upon treatment of an alcohol with diphenyl sulfide bis(trifluoromethanesulfonate). Initially, reaction of 4-methoxybenzyl alcohol with sodium dimethyl malonate was studied as a model system; that is, the diphenyl alkoxy sulfonium intermediate was generated by adding 1.2 eq of 4-methoxybenzyl alcohol to a mixture of trifluoromethanesulfonic anhydride and diphenyl sulfoxide in tetrahydrofuran (THF) at Ϫ78°C.…”

Section: Resultsmentioning

confidence: 99%

A Facile One-Pot Benzylation of Sodium Enolates Using Trifluoromethanesulfonic Anhydride and Diphenyl Sulfoxide

Takuwa

Minowa

Fujisawa

et al. 2005

CHEMICAL & PHARMACEUTICAL BULLETIN

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Alkylation of metal enolates is one of the most fundamental and frequently used reactions in organic synthesis. This reaction is generally accomplished by treating various metal enolates with alkylating reagents such as alkyl halides or alkyl sulfonates. Such reactions of metal enolates derived from ketones, 1) esters, 2) and b-keto esters 3) with alkyl halides afford a mixture of mono-, di-and poly-alkylated products, even when one equivalent each of base and alkylating reagent are used. For example, O-monobenzylated, Cmonobenzylated and C-dibenzylated products (5 : 45 : 50) were obtained by benzylation of ethyl acetate with benzyl bromide in dimethyl sulfoxide. 4)C-Alkylation of active methylene compounds with alcohols has recently been accomplished in a redox reaction system by Mitsunobu-type reactions, 5) and Tsunoda and coworkers 6) have also reported efficient methods for alkylation of active methylene compounds. However, with benzyl alcohol, it is reported that the concomitant double alkylation and/or an ether forming-reaction takes place. 7) Thus, it is important to develop an efficient approach to this type of reaction, since C-monobenzylation of enolates is an important area of synthetic organic chemistry.The ratio of C-or O-alkylation strongly depends on the nature of the alkylating reagent. Alkoxydiphenyl sulfonium species are known as efficient alkylating reagents in reactions with carbon nucleophiles. Similarly, sulfonium salts derived from dialkylsulfoxides and trifluoromethanesulfonic anhydride have been utilized previously in Swern-type oxidation, 8) sulfilimine synthesis, 9) and glycosylation reactions. 10)Here, we describe a facile one-pot C-benzylation using trifluoromethanesulfonic anhydride and diphenyl sulfoxide. 11) Results and DiscussionGeneration of an alkoxy sulfonium intermediate was first attempted using the bromodiphenyl sulfonium salt derived from diphenyl sulfide and bromine (Chart 1); that is, 1.0 eq of bromine was added to diphenyl sulfoxide in dichloromethane at Ϫ78°C. After stirring the mixture for 10 min, 4-methoxybenzyl alcohol and freshly-prepared sodium enolate of dimethyl malonate were continuously added, followed by slow warming to room temperature. However, the desired product was not obtained. We have previously reported that diphenyl sulfide bis(trifluoromethanesulfonate) reacts with styrene to generate the corresponding active sulfonium intermediate, which in turn reacts with amines to afford aziridines or b,g-unsaturated amines.12,13) Therefore, formation of an alkoxy diphenyl sulfonium intermediate was anticipated upon treatment of an alcohol with diphenyl sulfide bis(trifluoromethanesulfonate). Initially, reaction of 4-methoxybenzyl alcohol with sodium dimethyl malonate was studied as a model system; that is, the diphenyl alkoxy sulfonium intermediate was generated by adding 1.2 eq of 4-methoxybenzyl alcohol to a mixture of trifluoromethanesulfonic anhydride and diphenyl sulfoxide in tetrahydrofuran (THF) at Ϫ78°C. After stirring the mixture for 30 min, 3.0 eq of ...

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Section: Resultsmentioning

confidence: 99%

A Facile One-Pot Benzylation of Sodium Enolates Using Trifluoromethanesulfonic Anhydride and Diphenyl Sulfoxide

Takuwa

Minowa

Fujisawa

et al. 2005

CHEMICAL & PHARMACEUTICAL BULLETIN

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“…Xie and colleagues reported the synthesis of gem-disubstituted cyclopropanes 27 from the reaction of N -alkyl malonyl amides 26 and diphenylvinylsulfonium triflate 1 in the presence of the organic base DBU under mild conditions and with good yields ( Scheme 6 ) [ 33 ]. Similarly, reactions of primary amines and sulfonamides with vinylsulfonium salt 1 in the presence of mild base furnished aziridines [ 34 , 35 ].…”

Section: Reactions Of Vinylsulfonium Saltsmentioning

confidence: 99%

Recent Developments in Vinylsulfonium and Vinylsulfoxonium Salt Chemistry

2018

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This review describes advances in the literature since 2000 in the area of reactions of vinylsulfonium and vinylsulfoxonium salts, with a particular emphasis on stereoselective examples. Although the chemistry of vinylsulfonium salts was first explored back in the 1950s, and that of vinylsulfoxonium salts in the early 1970s, there has been renewed interest in these compounds since the turn of the century. This has been largely due to an increased appreciation for the many synthetic possibilities associated with these valuable electrophiles. The development of improved routes to vinylsulfonium salts allowing for their in situ generation has played a part in accelerating their study. In general, reactions of the two sulfur salt classes follow a similar mechanistic pathway: initial conjugate addition of a nucleophile to the β-position, followed by protonation of an ylide intermediate, and cyclization of tethered anion to afford monocyclic or bicyclic product (e.g. cyclopropane, aziridine, oxazole, oxazolidinone, γ-lactam or γ-lactone). Alternatively, reactions involve formation of a ylide intermediate followed by intramolecular Johnson-Corey-Chaykovsky reaction (epoxidation or cyclopropanation), and subsequent cyclization to afford the desired bicyclic product (e.g. fused bicyclic epoxide or cyclopropane).

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“…This effectively increases the resolution as the effect of Brownian motion is greatly reduced at forward scattering angles. At higher angles, Brownian motion causes a problem as it 'smears' out the velocity spectrum, making it difficult to resolve mixtures of particles with different mobilities [10].…”

Section: Heterodyne Opticsmentioning

confidence: 99%