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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Visible-light-driven reversible shuttle vicinal dihalogenation using lead halide perovskite quantum dot catalysts

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: Aug. 4, 2023

Abstract Dihalogenation of alkenes to the high-added value vicinal dihalides is a prominent process in modern synthetic chemistry. However, their effective conversion still requires use expensive and hazardous agents, sacrificial half-reaction coupling or primary energy input. Here, we show photocatalytically assisted shuttle (p-shuttle) strategy for redox-neutral reversible dihalogenation using low-cost stable 1,2-dihaloethane under visible light illumination. Energetic hot electrons from metal-halide perovskite QDs enable challenging photocatalytic reactions. Ultrafast laser transient absorption spectroscopy have unveiled matching with high reduction potential 1,2-dihaloethane, via two consecutive photoexcitation process. Powered by sustainable as only input, our new catalytic system dibromination, dichlorination even unexplored hetero-dihalogenation, shows good tolerance wide range at room temperature. In contrast homogeneous photocatalysts, chalcogenide other semiconductor catalysts, deliver previously unattainable performance photoredox turnover number over 120,000. This work provides opportunities visible-light-driven heterogeneous catalysis unlocking novel chemical transformations.

Language: Английский

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Rapid and Controlled Assembly of Polysubstituted Furans and Their Oligoaryls from Alkynes and Aldehydes Facilitated by Sequential Deprotonation

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 2, 2025

A new sequential deprotonation strategy of dimethyl sulfoxide (DMSO) and propargyl alcohol in the presence a base was developed for generation α-hydroxyl carbanion, which enables rapid controllable access to wide range valuable highly functionalized furans one pot from alkynes aldehydes under transition-metal- additive-free conditions. Preliminary mechanistic studies revealed crucial role DMSO. More importantly, deuterium labeling experiments confirmed formation carbanion.

Language: Английский

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Arylamines as More Strongly Reducing Organic Photoredox Catalysts than fac-[Ir(ppy)₃]

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(24), P. 15400 - 15415

Published: Dec. 1, 2022

Organic photoredox catalysts (OPCs) have the potential to replace precious-metal-based (PMPCs). Compared with strongly oxidizing OPCs, such as representative acridinium salts, however, recent development of reducing OPCs has been relatively sluggish. In this Perspective, bearing arylamine motifs are introduced. One advantages is their versatility in catalyst design, which makes it easier develop a capability superior that fac-[Ir(ppy)3], strongest reductant among commonly used PMPCs. Easy access structural diversity also contributes rapid appropriate for various applications, instance, not only simple organo-radical reactions but precise control polymer synthesis and properties through photocatalytic (organocatalyzed) atom-transfer radical polymerization. While light shorter wavelength (higher energy), near-ultraviolet light, typically involved conferring natures, strategies catalytic systems using longer (lower energy) visible including consecutive photoinduced electron transfer, emerging defacto standard. These design OPC systems, allow them achieve otherwise inaccessible described.

Language: Английский

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Blue Light Irradiated Metal-, Oxidant-, and Base-Free Cross-Dehydrogenative Coupling of C(sp²)–H and N–H Bonds: Amination of Naphthoquinones with Amines

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(11), P. 7401 - 7424

Published: May 12, 2023

Herein, we report a blue-light-driven amination of C(sp2)-H bond naphthoquinones and quinones with the N-H primary secondary amines for synthesis 2-amino-naphthoquinones 2-amino-quinones. The coupling wide array aliphatic, aromatic, chiral, primary, having electron donating (-CH3, -OCH3, -SCH3), withdrawing (-F, -Cl, -Br, -I), CO2H, -OH, -NH2 groups acidic protons selectively occurred to afford C-N coupled in 60-99% yields hydrogen gas as byproduct methanol solvent without using any additional reagents, additives, oxidant under blue light irradiation. Mechanistic insight by DFT computation, controlled experiments, kinetic isotopic effect, substitution effect substrates suggest that reaction proceeds radical pathway which naphthoquinone forms highly oxidizing naphthoquinonyl biradical upon irradiation (457 nm). Consequently, transfer from electron-rich amine an leads anion aminyl cation, followed proton delocalization leading carbon-centered radical. cross-coupling nitrogen radicals bond, subsequent elimination (which was also confirmed GC-TCD), affording 2-amino-1,4-naphthoquinone metal-, reagent-, base-, oxidant-free conditions.

Language: Английский

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The Future of (Radio)‐Labeled Compounds in Research and Development within the Life Science Industry

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(52)

Published: Aug. 23, 2023

In this review the applications of isotopically labeled compounds are discussed and put into context their future impact in life sciences. Especially discussing use pharma crop science industries to follow fate environment, vivo or complex matrices understand potential harm new chemical structures increase safety human society.

Language: Английский

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Light-driven redox deracemization of indolines and tetrahydroquinolines using a photocatalyst coupled with chiral phosphoric acid

Chemical Science, Journal Year: 2023, Volume and Issue: 14(7), P. 1715 - 1723

Published: Jan. 1, 2023

A light-driven redox deracemization to prepare optically pure cyclamines from their racemates is developed. This reaction provides a wide range of chiral indolines and tetrahydroquinolines with high yields enantioselectivities.

Language: Английский

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Reactivity of Superbasic Carbanions Generated via Reductive Radical‐Polar Crossover in the Context of Photoredox Catalysis

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(18)

Published: Feb. 26, 2024

Photocatalytic reactions involving a reductive radical-polar crossover (RRPCO) generate intermediates with carbanionic reactivity. Many of these proposed resemble highly reactive organometallic compounds. However, conditions their formation are generally not tolerated by isolated versions and often different reactivity is observed. Our investigations on nature under commonly used photocatalytic demonstrate that indeed best described as free, superbasic carbanions capable deprotonating common polar solvents usually assumed to be inert such acetonitrile, dimethylformamide, dimethylsulfoxide. Their basicity only towards but also electrophiles, aldehydes, ketones, esters, comparable the in gas-phase. Previously unsuccessful transformations thought result from lack explained high solvent weakly acidic protons reaction partners. An intuitive explanation for mode action photocatalytically generated provided, which enables methods verify mechanisms involve an RRPCO step identify reasons limitations current methods.

Language: Английский

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Organo-Photoredox Catalyzed gem-Difluoroallylation of Glycine and Glycine Residue in Peptides

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(6), P. 4056 - 4066

Published: March 7, 2024

An organo-photoredox catalyzed gem-difluoroallylation of glycine with α-trifluoromethyl alkenes via direct C(sp3)–H functionalization and C–F bond activation has been described. As a consequence, broad range gem-difluoroalkene-containing unnatural amino acids are afforded in moderate to excellent yields. This reaction exhibits multiple merits such as readily available starting materials, substrate scope, mild conditions. The feasibility this highlighted by the late-stage modification several peptides well improved vitro antifungal activity compound 3v toward Valsa mali compared that commercial azoxystrobin.

Language: Английский

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Selective Cross‐Ketonization of Carboxylic Acids Enabled by Metallaphotoredox Catalysis

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(52)

Published: Nov. 1, 2022

Abstract Carboxylic acids are attractive building blocks for synthetic chemistry because they chemically stable, abundant, and commercially available with substantial structural diversity. The process of combining two carboxylic to furnish a ketone is termed ketonization. This potentially valuable transformation that has been underutilized in organic synthesis due the harsh reaction conditions generally required lack selectivity obtained when coupling distinct acids. We report herein metallaphotoredox strategy selectively generates unsymmetrical ketones via cross‐ketonization structurally dissimilar Cross‐selectivity achieved by exploiting divergent reactivity differentially substituted towards critical one‐ two‐electron processes proposed mechanism. method broadly applicable variety functionalized It can also be applied similar steric profile differences their relative rates decarboxylation.

Language: Английский

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