Transition‐Metal‐Mediated and ‐Catalyzed C−F Bond Activation by Fluorine Elimination

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 58(2), P. 390 - 402

Published: June 28, 2018

Abstract The activation of carbon–fluorine (C−F) bonds is an important topic in synthetic organic chemistry. Metal‐mediated and ‐catalyzed elimination β‐ or α‐fluorine proceeds under milder conditions than oxidative addition to C−F bonds. initiated from organometallic intermediates having fluorine substituents on carbon atoms β α metal centers, respectively. Transformations through these processes (C−F bond cleavage), which are typically preceded by carbon–carbon (or carbon–heteroatom) formation, have been increasingly developed the past five years as methods. In this Minireview, we summarize applications transition‐metal‐mediated chemistry a historical perspective with early studies systematic recent studies.

Language: Английский

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Single Electron Transfer-Induced Redox Processes Involving N-(Acyloxy)phthalimides

ACS Catalysis, Journal Year: 2021, Volume and Issue: 11(3), P. 1640 - 1683

Published: Jan. 20, 2021

The past decade has witnessed the emergence of N-(acyloxy)phthalimides (NHPI esters) and its derivatives at forefront synthetic methods facilitating construction diverse molecular frameworks from readily available carboxylic acid feedstock. NHPI esters are predisposed to undergo reductive fragmentation via a single electron transfer (SET) process under thermal, photochemical, or electrochemical conditions generate corresponding carbon- nitrogen-centered radicals that participate in multitude transformations forge carbon–carbon carbon–heteroatom bonds. chemistry involving received broad applicability not only well-designed cascade annulations but also medicinal natural product synthesis. This comprehensive Review, broadly categorized according nature bond formation, details progress made this field since initial discovery by providing representative examples with mechanistic details, an emphasis on challenges future directions.

Language: Английский

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Recent progress on selective deconstructive modes of halodifluoromethyl and trifluoromethyl-containing reagents

Chemical Society Reviews, Journal Year: 2020, Volume and Issue: 49(24), P. 9197 - 9219

Published: Jan. 1, 2020

Halodifluoromethyl and trifluoromethyl-containing compounds can act various rolesviaselective cleavage modes to access more valuable fluorinated or nonfluorinated molecules.

Language: Английский

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Recent advances in the synthesis and applications of α-(trifluoromethyl)styrenes in organic synthesis

Chemical Communications, Journal Year: 2019, Volume and Issue: 55(90), P. 13486 - 13505

Published: Jan. 1, 2019

α-Trifluoromethylstyrene derivatives are versatile synthetic intermediates for the preparation of more complex fluorinated compounds. Much attention has been paid to these compounds by organic chemistry community, because they have successfully utilized in C-F bond activation a CF3 group, mainly including anionic SN2'-type substitution, cationic SN1'-type ipso-substitution and defluorinative functionalization with transition metals or photoredox catalysts. In addition, metal-catalyzed cycloaddition reactions α-trifluoromethylstyrenes developed construction cycloalkanes cycloalkenes containing fluoro trifluoromethyl groups. this review, we systematically summarized synthesis their applications chemistry, mechanisms were also discussed.

Language: Английский

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Nickel-catalyzed C–N bond activation: activated primary amines as alkylating reagents in reductive cross-coupling

Chemical Science, Journal Year: 2019, Volume and Issue: 10(16), P. 4430 - 4435

Published: Jan. 1, 2019

Nickel-catalyzed reductive cross coupling of activated primary amines with aryl halides under mild reaction conditions has been achieved for the first time. Due to avoidance stoichiometric organometallic reagents and external bases, scope regarding both partners is broad. Thus, a wide range substrates, natural products drugs diverse functional groups are tolerated. Moreover, experimental mechanistic investigations density theory (DFT) calculations in combination wavefunction analysis have performed understand catalytic cycle more detail.

Language: Английский

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Catalytic asymmetric reductive hydroalkylation of enamides and enecarbamates to chiral aliphatic amines

Nature Communications, Journal Year: 2021, Volume and Issue: 12(1)

Published: Feb. 26, 2021

Abstract To increase the reliability and success rate of drug discovery, efforts have been made to C( sp 3 ) fraction avoid flat molecules. -Rich enantiopure amines are most frequently encountered as chiral auxiliaries, synthetic intermediates for pharmaceutical agents bioactive natural products. Streamlined construction aliphatic has long regarded a paramount challenge. Mainstream approaches, including hydrogenation enamines imines, C–H amination, alkylation were applied synthesis with circumscribed skeleton structures; typically, carbon centre was adjacent an auxiliary aryl or ester group. Herein, we report mild general nickel-catalysed asymmetric reductive hydroalkylation effectively convert enamides enecarbamates into drug-like α-branched derivatives. This reaction involves regio- stereoselective hydrometallation enamide enecarbamate generate catalytic amount enantioenriched alkylnickel intermediate, followed by C–C bond formation via alkyl electrophiles.

Language: Английский

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Recent Advances in the Synthesis of Difluorinated Architectures from Trifluoromethyl Groups

Advanced Synthesis & Catalysis, Journal Year: 2021, Volume and Issue: 364(2), P. 234 - 267

Published: Nov. 29, 2021

Abstract Fluorine‐containing moieties are widely used in the pharmaceutical, agrochemical, and material fields. Thus, these structures of immense interest fields organic synthesis medicinal chemistry. Among various fluorinated groups, difluoromethyl unit has drawn increasing attention due to its unique pharmaceutical properties. In recent years, several methods for difluoromethylated compounds have been rapidly developed. However, most treat aromatic with excess difluoromethylating reagents, which often contain organometallic compounds, so transformations generally less environmentally friendly atom‐economical. this review, we summarize development new motifs or difluoroalkenes from trifluoromethylated trifluoromethyl alkenes via single C( sp 3 )−F bond cleavage. magnified image

Language: Английский

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Ni-Catalyzed Ligand-Controlled Regiodivergent Reductive Dicarbofunctionalization of Alkenes

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(27), P. 10282 - 10291

Published: June 24, 2021

Transition-metal-catalyzed dicarbofunctionalization of alkenes involving intramolecular Heck cyclization followed by intermolecular cross-coupling has emerged as a powerful engine for building heterocycles with sterically congested quaternary carbon centers. However, only exo-cyclization/cross-coupling products can be obtained; endo-selective cyclization/cross-coupling not been reported yet and still poses formidable challenge. We herein report the first example catalyst-controlled regiodivergent synthesis five- six-membered benzo-fused lactams bearing all-carbon Using chiral Pyrox- or Phox-type bidentate ligand, 5-exo cyclization/cross-couplings proceed favorably to produce indole-2-ones in good yields excellent regioselectivity enantioselectivities (up 98% ee). When C6-carboxylic acid-modified 2,2′-bipyridine was used 3,4-dihydroquinolin-2-ones were obtained through 6-endo-selective processes. This transformation is modular tolerant variety functional groups. The ligand rather than substrate structures precisely dictates pattern. Moreover, synthetic value this protocol demonstrated preparation biologically relevant molecules structural scaffolds.

Language: Английский

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Chromium-Catalyzed Allylic Defluorinative Ketyl Olefin Coupling

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(30), P. 11602 - 11610

Published: July 22, 2021

Herein we report a chromium-catalyzed allylic defluorinative ketyl olefin coupling between aldehydes and α-trifluoromethyl alkenes, which provides novel efficient access to diverse gem-difluorohomoallylic alcohols. Remarkably, the high chemoselectivity of this reaction enables conversion formyl moiety in presence various easily reducible functionalities including ketone, organohalides, aziridine, sulfone, alkyne, unactivated alkene. The utility method is demonstrated by simple derivatizations attached hydroxyl group products. preliminary mechanistic investigations suggest pathway with rate-limiting C–C forming step followed facile β-fluoro elimination.

Language: Английский

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A review of frustrated Lewis pair enabled monoselective C–F bond activation

Chemical Science, Journal Year: 2024, Volume and Issue: 15(8), P. 2712 - 2724

Published: Jan. 1, 2024

Frustrated Lewis pair (FLP) bond activation chemistry has greatly developed over the last two decades since seminal report of metal-free reversible hydrogen activation. Recently, FLP systems have been utilized to allow monoselective C-F (at equivalent sites) in polyfluoroalkanes. The problem 'over-defluorination' functionalization polyfluoroalkanes (where multiple fluoro-positions are uncontrollably functionalized) a long-standing chemical fluorocarbon for 80 years. mediated is complementary other solutions address and offers several advantages unique opportunities. This perspective highlights some these opportunities places development into context wider effort overcome 'over-defluorination'.

Language: Английский

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