Merging shuttle reactions and paired electrolysis for reversible vicinal dihalogenations

Science, Journal Year: 2021, Volume and Issue: 371(6528), P. 507 - 514

Published: Jan. 28, 2021

Vicinal dibromides and dichlorides are important commodity chemicals indispensable synthetic intermediates in modern chemistry that traditionally synthesized using hazardous elemental chlorine bromine. Meanwhile, the environmental persistence of halogenated pollutants necessitates improved approaches to accelerate their remediation. Here, we introduce an electrochemically assisted shuttle (e-shuttle) paradigm for facile scalable interconversion alkenes vicinal dihalides, a class reactions can be used both synthesize useful dihalogenated molecules from simple recycle waste material through retro-dihalogenation. The reaction is demonstrated 1,2-dibromoethane, as well 1,1,1,2-tetrachloroethane or 1,2-dichloroethane, dibrominate dichlorinate, respectively, wide range setup with inexpensive graphite electrodes. Conversely, hexachlorinated persistent pollutant lindane could fully dechlorinated benzene soil samples alkene acceptors.

Language: Английский

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Visible‐Light‐Induced Vicinal Dichlorination of Alkenes through LMCT Excitation of CuCl₂

Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 59(52), P. 23603 - 23608

Published: Sept. 14, 2020

Abstract This work demonstrates photoredox vicinal dichlorination of alkenes, based on the homolysis CuCl 2 in response to irradiation with visible light. catalysis proceeds via a ligand metal charge transfer process and provides an exciting opportunity for synthesis 1,2‐dichloride compounds using inexpensive, low‐molecular‐weight chlorine source. new exhibits wide substrate scope, excellent functional group tolerance, extraordinarily mild conditions does not require external ligands. Mechanistic studies show that ready formation atom radicals is responsible facile C−Cl bonds this synthetic process.

Language: Английский

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Catalytic Dynamic Kinetic Resolutions in Tandem to Construct Two-Axis Terphenyl Atropisomers

Journal of the American Chemical Society, Journal Year: 2020, Volume and Issue: 142(38), P. 16461 - 16470

Published: Aug. 28, 2020

The defined structure of molecules bearing multiple stereogenic axes is increasing relevance to materials science, pharmaceuticals, and catalysis. However, catalytic enantioselective approaches control remain synthetically challenging. We report the synthesis two-axis terphenyl atropisomers, with complementary strategies both chlorinated brominated variants, formed high diastereo- enantioselectivity. chemistry proceeds through a sequence two distinct dynamic kinetic resolutions: first, an atroposelective ring opening Bringmann-type lactones produces product one established axis chirality, second, stereoselective arene halogenation delivers second chirality established. In order achieve these results, class Brønsted basic guanidinylated peptides, which catalyze efficient chlorination, reported for first time. addition, bromination reported, also establishes axis. These bromo-terphenyls are accessible following discovery that chiral anion phase transfer catalysis by C2-symmetric phosphoric acids allows catalyst in stereochemistry-determining event. Accordingly, we fully catalyst-controlled stereodivergent all possible stereoisomers while demonstrating diastereodivergence significant levels enantioselectivity cases.

Language: Английский

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Urea group-directed organocatalytic asymmetric versatile dihalogenation of alkenes and alkynes

Nature Catalysis, Journal Year: 2021, Volume and Issue: 4(8), P. 692 - 702

Published: Aug. 9, 2021

Language: Английский

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Photocatalytic, modular difunctionalization of alkenes enabled by ligand-to-metal charge transfer and radical ligand transfer

Chemical Science, Journal Year: 2023, Volume and Issue: 15(1), P. 124 - 133

Published: Nov. 24, 2023

Simple iron salts are able to photocatalyze the diazidation, dichlorination, and fluorochlorination of alkenes via merger ligand-to-metal charge transfer (LMCT) either radical ligand (RLT) or fluorine atom (FAT).

Language: Английский

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Controlled partial transfer hydrogenation of quinolines by cobalt-amido cooperative catalysis

Nature Communications, Journal Year: 2020, Volume and Issue: 11(1)

Published: March 6, 2020

Catalytic hydrogenation or transfer of quinolines was thought to be a direct strategy access dihydroquinolines. However, the challenge is control chemoselectivity and regioselectivity. Here we report an efficient partial system operated by cobalt-amido cooperative catalyst, which converts 1,2-dihydroquinolines reaction with H

Language: Английский

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Catalytic Vicinal Dichlorination of Unactivated Alkenes

ACS Catalysis, Journal Year: 2019, Volume and Issue: 9(8), P. 7232 - 7237

Published: July 8, 2019

Organocatalytic strategies for the programmed, catalytic oxidation of π-bonds through regioselective halogenation remain comparatively underdeveloped. The vicinal dichlorination unactivated alkenes is a pertinent example, where stoichiometric reagents and prefunctionalization steps are often employed. This surprising given prominence 1,2-dichloro moiety in an array bioactive natural products both terrestrial marine origin. Inspired by Willgerodt's seminal discovery 1886 that PhICl2 can be generated passing Cl2(g) iodobenzene, has been designed on basis I(I)/I(III) manifold. In situ generation p-TolICl2 achieved using Selectfluor CsCl. Substrate scope, mechanistic delineation, preliminary validation enantiomeric variant established. Over century after initial Willgerodt reagent (PhICl2), operationally simple, alternative validated.

Language: Английский

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Enantioselective anti-Dihalogenation of Electron-Deficient Olefin: A Triplet Halo-Radical Pylon Intermediate

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(8), P. 4808 - 4818

Published: Feb. 16, 2023

The textbook alkene halogenation reaction establishes straightforward access to vicinal dihaloalkanes. However, a robust catalytic method for dihalogenizing electron-deficient olefins in an enantioselective manner is still under development, and its mechanism remains controversial. Herein, we disclose efficient regio-, anti-diastereo-, dibromination, bromochlorination, dichlorination reactions of enones catalyzed by chiral N,N'-dioxide/Yb(OTf)3 complex. With the combination electrophilic halogen halide salts as halogenating agents, array homo- heterodihalogenated derivatives achieved moderate good enantioselectivities. Moreover, DFT calculations reveal that novel triplet halo-radical pylon intermediate probable accounting exclusive regio- anti-diastereoselectivity.

Language: Английский

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Organoselenium-catalyzed enantioselective syn-dichlorination of unbiased alkenes

Tetrahedron, Journal Year: 2019, Volume and Issue: 75(31), P. 4086 - 4098

Published: June 1, 2019

Language: Английский

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Enantioselective Dihalogenation of Alkenes

Chemistry - A European Journal, Journal Year: 2020, Volume and Issue: 27(14), P. 4517 - 4530

Published: Sept. 25, 2020

Abstract The dihalogenation of alkenes is one the classic reactions in organic chemistry and a prime example an electrophilic addition reaction. often observed anti ‐selectivity this reaction can be explained by formation haliranium‐ion intermediate. Although dihalogenations have been studied for more than century, development reagent‐controlled, enantioselective has proved to very difficult. Only recently, significant progress achieved. In review, overview on current method provided mechanistic aspects that render transformation challenging are discussed.

Language: Английский

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