A General and Efficient Route for the Preparation of Phenyl-Substituted Vinyl Fluorides

Tsai, Hou-Jen; Lin, Keh‐Wen; Ting, Tzu‐hao; Burton, Donald J.

doi:10.1002/(sici)1522-2675(19991215)82:12<2231::aid-hlca2231>3.0.co;2-z

Cited by 13 publications

(6 citation statements)

References 16 publications

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“…β-Fluororesveratrol was prepared as described previously (Scheme ). , Further purity was achieved by prep-HPLC [Luna 15 μm PREP silica (2) 100 Å column, 75:25 n -hexanes/ethyl acetate, 20 mL/min, 280 nm; retention time of 46.0 min ( Z -isomer)]: 1 H NMR (500 MHz, acetone- d 6 ) δ 8.67 (s, 1H), 8.20 (s, 2H), 7.55 (d, J = 7.8 Hz, 2H), 6.91 (d, J = 8.3 Hz, 2H), 6.68 (s, 2H), 6.28 (s, 1H), 6.24 (d, J = 41.5 Hz, 1H); 19 F NMR (470 MHz, acetone- d 6 ) δ −114.24 (d, J = 41.3 Hz); 13 C NMR (125 MHz, acetone- d 6 ) δ 159.45 (s), 158.30 (d, 1 J CF = 256.2 Hz), 136.79 (d, 3 J CF = 2.6 Hz), 126.84 (d, 3 J CF = 7.7 Hz), 125.20 (d, 2 J CF = 28.4 Hz), 116.51 (d, 4 J CF = 2.2 Hz), 108.35 (d, 4 J CF = 8.1 Hz), 104.71 (d, 2 J CF = 9.6 Hz), 102.69 (d, J = 1.9 Hz). , …”

Section: Methodsmentioning

confidence: 99%

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Structure and Spectroscopy of Alkene-Cleaving Dioxygenases Containing an Atypically Coordinated Non-Heme Iron Center

et al. 2017

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Carotenoid cleavage oxygenases (CCOs) are non-heme iron enzymes that catalyze scission of alkene groups in carotenoids and stilbenoids to form biologically important products. CCOs possess a rare four-His iron center whose resting-state structure and interaction with substrates are incompletely understood. Here, we address this knowledge gap through a comprehensive structural and spectroscopic study of three phyletically diverse CCOs. The crystal structure of a fungal stilbenoid-cleaving CCO, CAO1, reveals strong similarity between its iron center and those of carotenoid-cleaving CCOs, but with a markedly different substrate-binding cleft. These enzymes all possess a five-coordinate high-spin Fe(II) center with resting-state Fe-His bond lengths of ~2.15 Å. This ligand set generates an iron environment more electropositive than those of other non-heme iron dioxygenases as observed by Mössbauer isomer shifts. Dioxygen (O2) does not coordinate iron in the absence of substrate. Substrates bind away (~4.7 Å) from the iron and have little impact on its electronic structure, thus excluding coordination-triggered O2 binding. However, substrate binding does perturb the spectral properties of CCO Fe–NO derivatives, indicating proximate organic substrate and O2-binding sites, which might influence Fe–O2 interactions. Together, these data provide a robust description of the CCO iron center and its interactions with substrates and substrate mimetics that illuminates commonalities as well as subtle and profound structural differences within the CCO family.

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Section: Methodsmentioning

confidence: 99%

“…29,30 4 J CF = 8.1 Hz), 104.71 (d, 2 J CF = 9.6 Hz), 102.69 (d, J = 1.9 Hz). 31,32 Protein Production. Cloning, Expression, and Purification of CAO1.…”

Section: ■ Materials and Methodsmentioning

confidence: 99%

Structure and Spectroscopy of Alkene-Cleaving Dioxygenases Containing an Atypically Coordinated Non-Heme Iron Center

et al. 2017

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“…Addition of HF·Py to a solution of 20 in DCM rapidly gave vinyl fluoride 31 , which could be isolated in 54% yield (the high volatility of the product compromises the yield). Tetrasubstituted fluoroalkenes such as 31 can be obtained by reaction of ketones with a lithiated α-fluorobenzyl phosphonate, but the latter reagent is thermally instable, and its formation requires the utilization of diethylaminosulfur trifluoride . A reaction of 20 with methanol in the presence of trifluoroacetic acid (TFA) gave the tetrasubstituted enol ether 32 .…”

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confidence: 99%

One-Pot Synthesis of Trisubstituted Triazenes from Grignard Reagents and Organic Azides

et al. 2018

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A simple and versatile method for the preparation of linear, trisubstituted triazenes is reported. The procedure is based on the reaction of Grignard reagents with 1-azido-4-iodobutane or 4-azidobutyl-4-methylbenzenesulfonate. These organic azides enable the regioselective formation of triazenes via an intramolecular cyclization step. The new method can be used for the preparation of aryl, heteroaryl, vinyl, and alkyl triazenes. The synthetic utility of vinyl triazenes is demonstrated by acid-induced C-N, C-O, C-F, C-P, and C-S bond-forming reactions.

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“…Interestingly, when the reactions of benzyl halides were carefully examined, formation of fluorovinyl sulfones was observed indicating that a second elimination step occurred after the initial substitution reaction. Vinyl fluorides can be prepared from electrophilic fluorination of vinyllithiums , or stannanes , via the Horner−Wadsworth−Emmons condensation of α-fluorophosphonates with carbonyls, − desulfonylation, , stannyldesulfonylation, − silyl and germyldesulfonylation , of fluorovinyl sulfones, as well as Peterson and Julia olefination. Fluorovinyl sulfones, precursors of vinyl fluorides, are commonly synthesized using the Horner−Wittig reaction.…”

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confidence: 99%

Efficient Nucleophilic Fluoromethylation and Subsequent Transformation of Alkyl and Benzyl Halides Using Fluorobis(phenylsulfonyl)methane

et al. 2009

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An efficient methodology for the nucleophilic fluoromethylation of alkyl and benzyl halides using alpha-fluoro-alpha-(phenylsulfonyl)methane (1) as a highly versatile reagent is reported. Using benzyl halides, stereospecific one-pot synthesis of alpha-fluorovinyl compounds such as alpha-fluorostyrylsulfones, alpha-fluorocinnamates, and alpha-fluorochalcones has been achieved. The methodology has been extended toward the synthesis of alpha-substituted fluoroalkane derivatives using selective reductive desulfonylation conditions.

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A General and Efficient Route for the Preparation of Phenyl-Substituted Vinyl Fluorides

Cited by 13 publications

References 16 publications

Structure and Spectroscopy of Alkene-Cleaving Dioxygenases Containing an Atypically Coordinated Non-Heme Iron Center

Structure and Spectroscopy of Alkene-Cleaving Dioxygenases Containing an Atypically Coordinated Non-Heme Iron Center

One-Pot Synthesis of Trisubstituted Triazenes from Grignard Reagents and Organic Azides

Efficient Nucleophilic Fluoromethylation and Subsequent Transformation of Alkyl and Benzyl Halides Using Fluorobis(phenylsulfonyl)methane

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