• 제목/요약/키워드: Electrophilic fluorination

검색결과 7건 처리시간 0.019초

Development of fluorination methodology for carbon-fluorine bond formation: old electrophilic fluorinating reagents

  • Bae, Dae Young;Lee, Eunsung
    • 대한방사성의약품학회지
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    • 제4권1호
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    • pp.11-15
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    • 2018
  • Electrophilic fluorinating reagents are typically efficient for carbon-fluorine (C-F) bonds formation due to their higher reactivity even under mild condition. Thus, they have been playing an important role to improve C-F bonds formation reactions via direct fluorination reaction with electrophilic fluorinating reagents or transition metal catalysis. Advances on the recent fluorination methods are mainly results of $Selectfluor^{TM}$'s capability on facile fluorination. In this mini-review, we describe synthesis and application of four old yet popular electrophilic fluorinating reagents such as N-fluorobenzenesulfonimide (NFSI), N-fluoropyridinium salts, $Selectfluor^{TM}$, and N-fluorosultam.

Catalytic Enantioselective Fluorination Reactions of α-Cyano Acetates and α-Cyanophosphonates Using Chiral Palladium Complexes

  • Kim, Sun-Mi;Kang, Young-Ku;Cho, Min-Je;Mang, Joo-Yang;Kim, Dae-Young
    • Bulletin of the Korean Chemical Society
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    • 제28권12호
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    • pp.2435-2441
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    • 2007
  • The catalytic enantioselective electrophilic fluorinations of active methane compounds promoted chiral palladium complexes have been developed. Treatment of α-cyano acetates and α-cyanoalkylphosphonates with N-fluorobenzenesulfonimide as the fluorine source under mild reaction conditions afforded the corresponding α-cyano-α-fluorinated adducts in high yields with excellent enantiomeric excesses (up to 99% ee). These reactions can be conducted in alcoholic solvents without any precaution to exclude water and moisture.

Enantioselective Fluorination of β-Keto Phosphonates and β-Ketoesters Catalyzed by Chiral Palladium Complexes

  • Lee, Na-Ri;Kim, Sun-Mi;Kim, Dae-Young
    • Bulletin of the Korean Chemical Society
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    • 제30권4호
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    • pp.829-836
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    • 2009
  • The catalytic enantioselective electrophilic fluorinations of active methine compounds promoted chiral palladium complexes have been developed. Treatment of $\beta$-keto phosphonates and $\beta$-ketoesters with N-fluorobenzenesulfonimide as the fluorine source under mild reaction conditions afforded the corresponding $\alpha$-fluorinated adducts in high yields with excellent enantiomeric excesses (up to 99% ee). These reactions can be conducted in alcoholic solvents without any precaution to exclude water and moisture.

[18F]Aryl fluorides from hypervalent iodine compounds

  • Chun, Joong-Hyun;Son, Jeongmin;Park, Jun Young;Yun, Mijin
    • 대한방사성의약품학회지
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    • 제3권1호
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    • pp.3-14
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    • 2017
  • Nucleophilic aromatic fluorination has been one of the most explored methods in fluorin-18 based radiochemistry. Unlike electrophilic $[^{18}F]$fluorination methods, no-carrier-added nucleophilic radiofluorination with cyclotron-produced $[^{18}F]$fluoride ion offers better specific radioactivity which is essential aspect to obtain good quality images from positron emission tomography. Contrary to amenable aliphatic radiofluorination, the development of reliable aromatic $[^{18}F]$fluorination methods has been pursued by many research groups; however, no viable method has yet been established. Recently, hypervalent iodine compound draws increasing attention as versatile radiolabeling precursor for various $[^{18}F]$fluoroarenes, since it bears the capacity to introduce fluorine-18 either on electron-deficient or electron-rich aryl ring with enhanced regiospecificity. Other classes of hypervalent iodine congeners often utilized in radiochemistry are iodylarenes, iodonium ylides, and spirocyclic iodonium ylides. Recently developed spirocyclic iodonium ylides have already been avidly employed to provide various $[^{18}F]$aryl fluorides with high labeling efficiency. This metal-free protocol would afford efficient routes, replacing the traditional approaches to $[^{18}F]$fluoroarenes, from prosthetic labeling synthons to complex PET radiotracers.

친전자성 불소치환 직접플루오르화 반응에 의한 Perfluoropolyether 중간체의 합성 (Synthesis of a Perfluoropolyether Intermediate via Electrophilic Fluorine-Substituting Direct Fluorination)

  • 윤석민;임재원;정의경;박인준;이영석
    • 폴리머
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    • 제35권2호
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    • pp.166-170
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    • 2011
  • 본 연구에서는 hexafluoropropylene oxide(HFPO)의 개환중합 및 메틸에스테르화 반응을 통하여 $CH_3$ 말단 관능기를 가진 perfluoropolyether(PFPE) 중간체 (TP-$COOCH_3$)를 합성하고, 이를 친전자성 불소치환 직접플루오르화법을 통하여 $CF_3$ 말단 관능기를 가진 PFPE 중간체 (TP-$COOCF_3$)를 합성하였다. 또한 반응조건인 용매의 양, 혼합가스 불소 부분압 및 반응시간이 TP-$COOCF_3$ 합성에 미치는 영향에 대하여 고찰하였다. 실험결과, 플루오르화 반응은 온화한 조건에서 장시간 진행하는 것이 부반응을 최소화하여 전환율을 향상시키는 것으로 나타났다. FTIR NMR 결과로부터 TP-$COOCH_3$의 말단 $CH_3$ 관능기가 친전자성 불소치환 직접플루오르화를 통하여 $CF_3$ 관능기로 치환되어 최종 생성물인 TP-$COOCF_3$가 95.4%의 전환율로 합성된 것을 확인할 수 있었다.