Photocatalytic Late-Stage C–H Functionalization

Chemical Reviews, Journal Year: 2023, Volume and Issue: 123(8), P. 4237 - 4352

Published: Jan. 24, 2023

The emergence of modern photocatalysis, characterized by mildness and selectivity, has significantly spurred innovative late-stage C–H functionalization approaches that make use low energy photons as a controllable source. Compared to traditional strategies, photocatalysis paves the way toward complementary and/or previously unattainable regio- chemoselectivities. Merging compelling benefits with workflow offers potentially unmatched arsenal tackle drug development campaigns beyond. This Review highlights photocatalytic strategies small-molecule drugs, agrochemicals, natural products, classified according targeted bond newly formed one. Emphasis is devoted identifying, describing, comparing main mechanistic scenarios. draws critical comparison between established ionic chemistry photocatalyzed radical-based manifolds. aims establish current state-of-the-art illustrate key unsolved challenges be addressed in future. authors aim introduce general readership functionalization, specialist practitioners evaluation methodologies, potential for improvement, future uncharted directions.

Language: Английский

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A Perspective on Late-Stage Aromatic C–H Bond Functionalization

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(6), P. 2399 - 2414

Published: Jan. 27, 2022

Late-stage functionalization of C-H bonds (C-H LSF) can provide a straightforward approach to the efficient synthesis functionalized complex molecules. However, LSF is challenging because bond must be in presence various other functional groups. In this Perspective, we evaluate aromatic on basis four criteria─reactivity, chemoselectivity, site-selectivity, and substrate scope─and our own views current challenges as well promising strategies areas growth going forward.

Language: Английский

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Contact-electro-catalysis for the degradation of organic pollutants using pristine dielectric powders

Nature Communications, Journal Year: 2022, Volume and Issue: 13(1)

Published: Jan. 10, 2022

Mechanochemistry has been studied for some time, but research on the reactivity of charges exchanged by contact-electrification (CE) during mechanical stimulation remains scarce. Here, we demonstrate that electrons transferred CE between pristine dielectric powders and water can be utilized to directly catalyze reactions without use conventional catalysts. Specifically, frequent at Fluorinated Ethylene Propylene (FEP) - interface induces electron-exchanges, thus forming reactive oxygen species degradation an aqueous methyl orange solution. Contact-electro-catalysis, conjunction CE, mechanochemistry catalysis, proposed as a general mechanism, which demonstrated effective various materials, such Teflon, Nylon-6,6 rubber. This original catalytic principle not only expands range also enables us envisage processes through mechano-induced contact-electrification.

Language: Английский

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Metal-catalysed C–H bond activation and borylation

Chemical Society Reviews, Journal Year: 2022, Volume and Issue: 51(12), P. 5042 - 5100

Published: Jan. 1, 2022

Transition metal-catalysed direct borylation of hydrocarbons via C–H bond activation has received a remarkable level attention as popular reaction in the synthesis organoboron compounds owing to their synthetic versatility.

Language: Английский

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Electrochemical reactor dictates site selectivity in N-heteroarene carboxylations

Nature, Journal Year: 2023, Volume and Issue: 615(7950), P. 67 - 72

Published: Jan. 5, 2023

Language: Английский

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Selective [2σ + 2σ] Cycloaddition Enabled by Boronyl Radical Catalysis: Synthesis of Highly Substituted Bicyclo[3.1.1]heptanes

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(7), P. 4304 - 4310

Published: Feb. 10, 2023

In contrast to the traditional and widely-used cycloaddition reactions involving at least a π bond component, [2σ + 2σ] radical between bicyclo[1.1.0]butanes (BCBs) cyclopropyl ketones has been developed provide modular, concise, atom-economical synthetic route substituted bicyclo[3.1.1]heptane (BCH) derivatives that are 3D bioisosteres of benzenes core skeleton number terpene natural products. The reaction was catalyzed by combination simple tetraalkoxydiboron(4) compound B2pin2 3-pentyl isonicotinate. broad substrate scope demonstrated synthesizing series new highly functionalized BCHs with up six substituents on 99% isolated yield. Computational mechanistic investigations supported pyridine-assisted boronyl catalytic cycle.

Language: Английский

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Late-Stage C–H Functionalization of Azines

Chemical Reviews, Journal Year: 2023, Volume and Issue: 123(12), P. 7655 - 7691

Published: May 3, 2023

Azines, such as pyridines, quinolines, pyrimidines, and pyridazines, are widespread components of pharmaceuticals. Their occurrence derives from a suite physiochemical properties that match key criteria in drug design is tunable by varying their substituents. Developments synthetic chemistry, therefore, directly impact these efforts, methods can install various groups azine C–H bonds particularly valuable. Furthermore, there growing interest late-stage functionalization (LSF) reactions focus on advanced candidate compounds often complex structures with multiple heterocycles, functional groups, reactive sites. Because factors electron-deficient nature the effects Lewis basic N atom, distinct arene counterparts, application LSF contexts difficult. However, have been many significant advances reactions, this review will describe progress, much which has occurred over past decade. It possible to categorize radical addition processes, metal-catalyzed activation transformations occurring via dearomatized intermediates. Substantial variation reaction within each category indicates both rich reactivity heterocycles creativity approaches involved.

Language: Английский

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The interplay of polar effects in controlling the selectivity of radical reactions

Nature Synthesis, Journal Year: 2022, Volume and Issue: 1(9), P. 682 - 695

Published: Aug. 1, 2022

Language: Английский

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Covalent Organic Frameworks as Porous Pigments for Photocatalytic Metal-Free C–H Borylation

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(13), P. 7592 - 7599

Published: March 21, 2023

Covalent organic frameworks (COFs) are highly promising as heterogeneous photocatalysts due to their tunable structures and optoelectronic properties. Though COFs have been used photocatalysts, they mainly employed in water splitting, carbon dioxide reduction, hydrogen evolution reactions. A few examples synthesis using metal-anchored COF were reported. Herein, we report stable β-keto-enamine-based for metal-free C–B bond formation Three different availed this purpose. Their photocatalysis performances monitored 12 substrates, like quinolines, pyridines, pyrimidines. All the showcase moderate-to-high yields (up 96%) depending upon substrate's molecular functionality. High crystallinity, a large surface area, low band gap, suitable position result highest catalytic activity of TpAzo COF. The thorough mechanistic investigation further highlights crucial role light-harvesting capacity, charge separation efficiency, current density during catalysis. light absorbance capacity plays critical catalysis maximized near COF's absorption maxima. high photostability as-synthesized offers reusability several (>5) cycles.

Language: Английский

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Lewis Base–Boryl Radicals Enabled Borylation Reactions and Selective Activation of Carbon–Heteroatom Bonds

Accounts of Chemical Research, Journal Year: 2022, Volume and Issue: 56(2), P. 169 - 186

Published: Dec. 26, 2022

ConspectusThe past decades have witnessed tremendous progress on radical reactions. However, in comparison with carbon, nitrogen, oxygen, and other main group element centered radicals, the synthetic chemistry of boron radicals was less studied, mainly due to high electron-deficiency instability such 3-center-5-electron species. In 1980s, Roberts co-workers found that coordination a Lewis base (amines or phosphines) center could form 4-center-7-electron boryl (Lewis base-boryl LBRs) are be more stable. only limited applications were developed. 2008, Curran achieved breakthrough discovery N-heterocyclic carbene (NHC) which enable range reduction polymerization Despite these exciting findings, powerful valuable LBRs would expected, given structures reactivities easily modulated, provide ample opportunities discover new this Account, summary our key contributions LBR-enabled borylation reactions selective activation inert carbon-heteroatom bonds will presented.Organoboron compounds shown versatile chemical society, their syntheses rely principally ionic The development mechanistically different allows synthesizing products inaccessible by traditional methods. For purpose, we progressively developed series NHC-boryl mediated chemo-, regio-, stereoselective alkenes alkynes, wide variety structurally diverse organoboron molecules successfully prepared. utility borylated also demonstrated. Furthermore, disclosed photoredox protocol for oxidative generation enabled useful defluoroborylation arylboration reactions.Selective bond is an ideal way convert simple starting materials value-added products, while cleavage bonds, particular chemoselectivity control when multiple identical present similar environments, remains long-standing challenge. We envisaged finely tuning properties might solution address Recently, 4-dimethylaminopyridine (DMAP)-boryl promoted sequential C-F functionalization trifluoroacetic acid derivatives, α-C-F selectively snipped via spin-center shift mechanism. This strategy enables facile conversion abundantly available highly mono- difluorinated molecules. Encouraged finding, further three-step sequence construct all-carbon quaternary centers from trichloromethyl groups, where three C-Cl cleaved rational choice suitable precursors each step. dehydroxylative alkylation α-hydroxy carboxylic derivatives achieved, allowing efficient some biomass platform value products.

Language: Английский

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