Efficient Docking–Migration Strategy for Selective Radical Difluoromethylation of Alkenes

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 57(52), P. 17156 - 17160

Published: Nov. 6, 2018

Abstract Radical‐mediated difunctionalization of alkenes is a powerful tactic for olefin utilization. However, the transformation unactivated still remains formidable challenge. Now conceptually new docking–migration strategy presented with photoredox catalysis. Both activated and are suitable substrates. A vast array functional groups compatible mild reaction conditions. Heteroaryl difluoromethyl concomitantly incorporated into alkenes, leading to synthetically valuable products that readily converted variety fluorine‐containing molecules. The protocol provides kinetic control stereoselectivity cycloalkenes generate unusual cis‐products, offers an efficient approach late‐stage functionalization complex natural drug portfolio dual‐function reagents prepared elusive radical alkenes.

Language: Английский

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Atom Transfer Radical Addition to Alkynes and Enynes: A Versatile Gold/Photoredox Approach to Thio-Functionalized Vinylsulfones

ACS Catalysis, Journal Year: 2018, Volume and Issue: 8(9), P. 8237 - 8243

Published: July 25, 2018

An efficient intermolecular atom-transfer addition reaction of alkynes via the combination visible-light photoredox catalysis and gold has been developed, affording diverse trifluoromethylthio- difluoromethylthio-functionalized vinylsulfones with high stereoselectivity in good yields. Thiosulfonylation enyne can also be realized for constructing functionalized carbo- heterocycles through a radical cascade cyclization process. These reactions proceed gold-assisted sulfonyl pathway.

Language: Английский

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Radical Alkynyltrifluoromethylation of Alkenes Initiated by an Electron Donor–Acceptor Complex

Organic Letters, Journal Year: 2017, Volume and Issue: 19(5), P. 1240 - 1243

Published: Feb. 16, 2017

Radical alkynyltrifluoromethylation of alkenes with actylenic triflones has been achieved. This radical chain reaction is initiated by a catalytic amount an electron-donor–acceptor complex composed Togni's reagent and N-methylmorpholine. transformation proceeds under exceptionally mild operationally simple conditions. A variety are compatible in this protocol including aliphatic alkenes, vinyl ethers, enecarbamates, styrenes, even acrylates, providing diverse β- trifluoromethyl alkynes good to excellent yields.

Language: Английский

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Selective Defluoroallylation of Trifluoromethylarenes

Journal of the American Chemical Society, Journal Year: 2019, Volume and Issue: 141(36), P. 14120 - 14125

Published: Aug. 22, 2019

We report a fluoride-initiated coupling reaction between trifluoromethylarenes and allylsilanes to access allylated α,α-difluorobenzylic compounds. This method's utility is demonstrated through 30 mmol scale reaction, sequential allylation/derivatization protocol multiple examples of site-selective trifluoromethylarene allylation. Initial mechanistic studies suggest base-induced single electron transfer pathway responsible for the high efficiency selectivity this novel C–F substitution process.

Language: Английский

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Copper-Catalyzed Difluoromethylation of Aryl Iodides with (Difluoromethyl)zinc Reagent

Organic Letters, Journal Year: 2016, Volume and Issue: 18(15), P. 3686 - 3689

Published: July 21, 2016

The combination of difluoroiodomethane and zinc dust or diethylzinc can readily lead to (difluoromethyl)zinc reagents. Therefore, the first copper-catalyzed difluoromethylation aryl iodides with reagents is accomplished afford difluoromethylated arenes. reaction proceeds efficiently through ligand/activator-free operation without addition ligands for copper catalyst (e.g., phen bpy) activators reagent KF, CsF, NaO-t-Bu). Moreover, transmetalation CF2H group from even at room temperature form cuprate [Cu(CF2H)2]−.

Language: Английский

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Nickel-Catalyzed Four-Component Carbocarbonylation of Alkenes under 1 atm of CO

Journal of the American Chemical Society, Journal Year: 2020, Volume and Issue: 142(42), P. 18191 - 18199

Published: Sept. 28, 2020

Transition-metal-catalyzed carbonylation is one of the most straightforward strategies to prepare carbonyl compounds. However, compared well-established noble-metal-catalyzed reactions, analogue coupling via base-metal, nickel catalysis has received less attention because easy formation highly toxic and unreactive Ni(CO)4 species between Ni(0) CO. To date, use inexpensive widely available carbon monoxide (CO) gas for nickel-catalyzed reaction remains challenging, four-component carbonylative not been reported yet. Here, we report a selective carbocarbonylation alkenes under 1 atm (1 atm) CO efficiently achieve an array complex compounds, including fluorinated amino acids oligopeptides great interest in medicinal chemistry chemical biology. This relies on one-pot cascade process assemble CO, arylboronic acids, difluoroalkyl electrophiles across carbon-carbon double bond alkenes, paving new way base-metal-catalyzed reaction.

Language: Английский

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Transition-metal-free decarboxylative C3-difluoroarylmethylation of quinoxalin-2(1H)-ones with α,α-difluoroarylacetic acids

Organic Chemistry Frontiers, Journal Year: 2019, Volume and Issue: 6(8), P. 1173 - 1182

Published: Jan. 1, 2019

A facile and efficient transition-metal-free decarboxylative radical coupling reaction of α,α-difluoroarylacetic acids with quinoxalin-2(1H)-ones has been developed under mild conditions.

Language: Английский

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General and Mild Nickel-Catalyzed Cyanation of Aryl/Heteroaryl Chlorides with Zn(CN)₂: Key Roles of DMAP

Organic Letters, Journal Year: 2017, Volume and Issue: 19(8), P. 2118 - 2121

Published: April 5, 2017

A new and general nickel-catalyzed cyanation of hetero(aryl) chlorides using less toxic Zn(CN)2 as the cyanide source has been developed. The reaction relies on use inexpensive NiCl2·6H2O/dppf/Zn catalytic system DMAP additive, allowing to occur under mild conditions (50-80 °C) with wide functional group tolerance. was found be crucial for successful transformation, likely proceeds via a Ni(0)/Ni(II) catalysis based mechanistic studies. method also successfully extended aryl bromides iodides.

Language: Английский

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Photoredox-Catalyzed Hydrodifluoroalkylation of Alkenes Using Difluorohaloalkyl Compounds and a Hantzsch Ester

The Journal of Organic Chemistry, Journal Year: 2017, Volume and Issue: 82(10), P. 5469 - 5474

Published: May 5, 2017

Photoredox-catalyzed hydrodifluoroalkylation of alkenes proceeded smoothly in the presence a Hantzsch ester as hydrogen source under visible light irradiation. The reaction was also applicable to alkynes, and continuous photo flow successful.

Language: Английский

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Copper/B₂pin₂-catalyzed C–H difluoroacetylation–cycloamidation of anilines leading to the formation of 3,3-difluoro-2-oxindoles

Chemical Communications, Journal Year: 2016, Volume and Issue: 53(14), P. 2222 - 2225

Published: Dec. 21, 2016

An original and efficient synthesis of 3,3-difluoro-2-oxindole derivatives has been developed via copper/B2pin2-catalyzed difluoroacetylation aniline C-H activation followed by intramolecular amidation. In this method, amino groups in primary, secondary or tertiary anilines act as directing groups, providing ortho-difluoroacetylated products regioselectively. And the first two cases, further amidation affords a one-pot strategy. This method facilitates compound A potent selective EP3 receptor antagonist only five steps 13% yield instead previously reported nine overall 4% yield.

Language: Английский

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