Photons or Electrons? A Critical Comparison of Electrochemistry and Photoredox Catalysis for Organic Synthesis

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(2), P. 2487 - 2649

Published: Nov. 9, 2021

Redox processes are at the heart of synthetic methods that rely on either electrochemistry or photoredox catalysis, but how do and catalysis compare? Both approaches provide access to high energy intermediates (e.g., radicals) enable bond formations not constrained by rules ionic 2 electron (e) mechanisms. Instead, they 1e mechanisms capable bypassing electronic steric limitations protecting group requirements, thus enabling chemists disconnect molecules in new different ways. However, while providing similar intermediates, differ several physical chemistry principles. Understanding those differences can be key designing transformations forging disconnections. This review aims highlight these similarities between comparing their underlying principles describing impact electrochemical photochemical methods.

Language: Английский

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Photoinduced Copper-Catalyzed Asymmetric C–O Cross-Coupling

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(33), P. 13382 - 13392

Published: Aug. 10, 2021

The construction of carbon–heteroatom bonds is one the most active areas research in organic chemistry because function molecules often derived from presence heteroatoms. Although considerable advances have recently been achieved radical-involved catalytic asymmetric C–N bond formation, there has little progress corresponding C–O bond-forming processes. Here, we describe a photoinduced copper-catalyzed cross-coupling readily available oxime esters and 1,3-dienes to generate diversely substituted allylic with high regio- enantioselectivity (>75 examples; up 95% ee). reaction proceeds at room temperature under excitation by purple light-emitting diodes (LEDs) features use single, earth-abundant copper-based chiral catalyst as both photoredox for radical generation source induction coupling. Combined experimental density functional theory (DFT) computational studies suggest formation π-allylcopper complexes redox-active bifunctional reagents through radical–polar crossover process.

Language: Английский

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Photochemical radical cyclization reactions with imines, hydrazones, oximes and related compounds

Chemical Society Reviews, Journal Year: 2021, Volume and Issue: 50(13), P. 7418 - 7435

Published: Jan. 1, 2021

Photochemical reactions of imines, hydrazones, oximes and related compounds provides an efficient access to radical intermediates in the synthesis heterocycles.

Language: Английский

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Reactivity of oximes for diverse methodologies and synthetic applications

Nature Synthesis, Journal Year: 2022, Volume and Issue: 1(1), P. 24 - 36

Published: Jan. 12, 2022

Language: Английский

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Radical transformations for allene synthesis

Chemical Science, Journal Year: 2022, Volume and Issue: 13(29), P. 8491 - 8506

Published: Jan. 1, 2022

Allenes are valuable organic molecules that feature unique physical and chemical properties. They not only often found in natural products, but also act as versatile building blocks for the access of complex molecular targets, such pharmaceuticals, functional materials. Therefore, many remarkable elegant methodologies have been established synthesis allenes. Recently, more methods radical allenes developed, clearly emphasizing associated great synthetic values. In this perspective, we will discuss recent important advances

Language: Английский

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Catalyst Selection over an Electrochemical Reductive Coupling Reaction toward Direct Electrosynthesis of Oxime from NO_x and Aldehyde

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(9), P. 6294 - 6306

Published: Feb. 20, 2024

Aqueous electrochemical coupling reactions, which enable the green synthesis of complex organic compounds, will be a crucial tool in synthetic chemistry. However, lack informed approaches for screening suitable catalysts is major obstacle to its development. Here, we propose pioneering reductive reaction toward direct electrosynthesis oxime from NOx and aldehyde. Through integrating experimental theoretical methods, screen out optimal catalyst, i.e., metal Fe that facilitates enrichment C–N key intermediates, all leading high yields (e.g., ∼99% yield benzaldoxime) over Fe. With divided flow reactor, achieve benzaldoxime production 22.8 g h–1 gcat–1 ∼94% isolated yield. This work not only paves way industrial mass via but also offers references catalyst selection other reactions.

Language: Английский

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Nickel-Catalyzed Modular Four-Component 1,4-Alkylcarbonylation of 1,3-Enynes to Tetra-Substituted CF₃–Allenyl Ketones

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(4), P. 2144 - 2150

Published: Jan. 25, 2024

The modular four-component carbonylation of unsaturated hydrocarbons represents an elegant strategy for the one-pot synthesis complex carbonyl compounds. However, this is currently focused on 1,2-difunctionalization olefins or alkynes, and 1,4-alkylcarbonylation 1,3-enynes remains unexplored. In study, we report a Ni-catalyzed CF3-containing under 1 atm CO, which affords tetra-substituted CF3-allenyl ketones with good yields selectivity. This protocol features mild conditions, broad substrate scope, acceptable functional group compatibility. Control experiments revealed that reactivity oxime esters (regulated by leaving groups) polarity matching are crucial success cascade. Preliminary mechanistic studies suggest acyl nickel key intermediate in transformation.

Language: Английский

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Three-component 1,2-dicarbofunctionalization of alkenes involving alkyl radicals

Chemical Communications, Journal Year: 2021, Volume and Issue: 58(6), P. 730 - 746

Published: Dec. 8, 2021

This article provides a comprehensive perspective on three-component 1,2-dicarbofunctionalization of alkenes involving alkyl radicals, which generated from structurally diverse electrophilic and nucleophilic precursors under mild conditions.

Language: Английский

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Oxime‐Derived Iminyl Radicals in Selective Processes of Hydrogen Atom Transfer and Addition to Carbon‐Carbon π‐Bonds

Advanced Synthesis & Catalysis, Journal Year: 2021, Volume and Issue: 363(10), P. 2502 - 2528

Published: March 25, 2021

Abstract Oximes represent one of the fundamental organic compound classes with a wide range synthetic applications. In last decade O ‐substituted oximes were recognized as synthetically available and versatile precursors iminyl radicals via one‐electron oxidation or reduction employing visible light photoredox catalysts, salts abundant metals (such Cu Fe), other convenient reagents. Iminyl are powerful synthons for various processes cyclization, ring‐opening, CH‐functionalization, coupling. The present review is focused on methods based oxime‐derived developed in few years excluding ring opening reactions cyclic that summarized recent publications. consists two main parts: (1) involving 1,n‐hydrogen atom transfer (n=5 most cases) (2) addition radical to carbon‐carbon π‐bond. magnified image

Language: Английский

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Cyanation: a photochemical approach and applications in organic synthesis

Organic Chemistry Frontiers, Journal Year: 2021, Volume and Issue: 8(12), P. 3166 - 3200

Published: Jan. 1, 2021

This review summarises the photocatalytic cyanation strategies to construct C(sp²)–CN, C(sp³)–CN and X–CN (X = N, S) bonds.

Language: Английский

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