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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Visible light-promoted reactions with diazo compounds: a mild and practical strategy towards free carbene intermediates

Chemical Society Reviews, Journal Year: 2020, Volume and Issue: 49(19), P. 6833 - 6847

Published: Jan. 1, 2020

Carbenes are important intermediates in organic chemistry and have been widely applied various types of reactions, ranging from cycloaddition reactions sigmatropic rearrangements to C-H functionalizations, thus allowing the rapid construction densely functionalized molecules. Over past decades, remarkable progress has achieved metal-catalyzed carbene transfer reactions. Nevertheless, realizing these transformations under milder and/or greener conditions is still highly desirable. Only recently, visible light-promoted diazo compounds via free emerged as a practical, mild powerful tool. In this tutorial review, we summarize latest advances area, aiming at providing clear overview on reaction design, mechanistic scenarios potential future developments.

Language: Английский

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Visible light photocatalysis in the late-stage functionalization of pharmaceutically relevant compounds

Chemical Society Reviews, Journal Year: 2020, Volume and Issue: 50(2), P. 766 - 897

Published: Dec. 22, 2020

Recent developments and future prospects of visible-light photocatalysis in the late-stage functionalization pharmaceuticals natural bioactive compounds.

Language: Английский

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Recent developments in photochemical reactions of diazo compounds

Organic & Biomolecular Chemistry, Journal Year: 2018, Volume and Issue: 17(3), P. 432 - 448

Published: Dec. 7, 2018

Chemistry of diazo compounds is dominated by transition metal catalysis but recently, photoinitiated reactions have attracted a lot attention. This mini-review describes recent discoveries on the reactivity under light irradiation.

Language: Английский

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Highly enantioselective carbene insertion into N–H bonds of aliphatic amines

Science, Journal Year: 2019, Volume and Issue: 366(6468), P. 990 - 994

Published: Nov. 22, 2019

A tag team approach to forming C–N bonds Many pharmaceutical compounds contain carbon-nitrogen (C–N) in just one of two mirror-image orientations. Forging these with electron-rich nitrogen reactants is challenging because the groups can coordinate with, and thus interfere catalyst. Li et al. report a cooperative overcoming this obstacle (see Perspective by Ovian Jacobsen). They used copper catalyst activate carbon reactant then hydrogen-bonding thiourea set product geometry high selectivity. The reaction compatible broad range diazo ester amine coupling partners. Science , issue p. 990 ; see also 948

Language: Английский

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Blue‐Light‐Induced Carbene‐Transfer Reactions of Diazoalkanes

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 58(4), P. 1203 - 1207

Published: Nov. 27, 2018

Abstract Carbenes are very important reactive intermediates to access a variety of complex molecules and applied widely in organic synthesis drug discovery. Typically, their chemistry is accessed by the use transition metal catalysts. Herein, we describe application low‐energy blue light for photochemical generation carbenes from donor–acceptor diazoalkanes. This catalyst‐free operationally simple approach enables highly efficient cyclopropenation reactions with alkynes rearrangement sulfides under mild reaction conditions, which can be utilized both batch continuous‐flow processes.

Language: Английский

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Lightening Diazo Compounds?

ACS Sustainable Chemistry & Engineering, Journal Year: 2021, Volume and Issue: 9(27), P. 8895 - 8918

Published: June 25, 2021

The development of new sustainable reactions and protocols is essential to fulfill the growing demands every branch organic chemistry for greener synthetic methodologies. In this context, use visible light as only source energy highly appealing. Since diazo compounds are valuable reagents in synthesis, their transformations realized a manner interest. High reactivity easy availability make them suitable solar-driven transformations. Indeed, photochemical have recently proven alternative transition metal catalysis. perspective, we highlight applications these under irradiation, particularly focusing on recent advancements. These include generation carbenes radicals which involve many relevant reactions, [2+1]-cycloadditions, X–H C–H insertions, Wolff rearrangement, more. Mechanistic aspects processes briefly addressed give readers deeper understanding rules underlying photoreactivity compounds. We conclude by emphasizing significant advancements discussing challenges future developments photochemistry reagents.

Language: Английский

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Recent Perspectives on Rearrangement Reactions of Ylides via Carbene Transfer Reactions

Chemistry - A European Journal, Journal Year: 2020, Volume and Issue: 27(4), P. 1270 - 1281

Published: Aug. 5, 2020

Abstract Among the available methods to increase molecular complexity, sigmatropic rearrangements occupy a distinct position in organic synthesis. Despite being known for over century rearrangement reactions of ylides via carbene transfer reaction have only recently come age. Most ylide mediated processes involve rupture σ‐bond and formation new bond between π‐bond negatively charged atom followed by simultaneous redistribution π‐electrons. This minireview describes advances this research area made recent years, which now opens up metal‐catalyzed enantioselective reactions, metal‐free photochemical novel pathways that can be accessed intermediates.

Language: Английский

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Unlocking novel reaction pathways of diazoalkanes with visible light

Chemical Communications, Journal Year: 2022, Volume and Issue: 58(17), P. 2788 - 2798

Published: Jan. 1, 2022

In this feature article, the photolysis and dye-sensitized reactions of diazoalkanes are discussed applications in organic synthesis presented.

Language: Английский

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Visible Light-Induced Reactions of Diazo Compounds and Their Precursors

Chemical Reviews, Journal Year: 2024, Volume and Issue: 124(11), P. 7214 - 7261

Published: May 16, 2024

In recent years, visible light-induced reactions of diazo compounds have attracted increasing attention in organic synthesis, leading to improvement existing reactions, as well the discovery unprecedented transformations. Thus, photochemical or photocatalytic generation both carbenes and radicals provide milder tools toward these key intermediates for many valuable However, vast majority transformations represent new reactivity modes compounds, which are achieved by decomposition photoredox catalysis. particular, use a redox-active photocatalysts opens avenue plethora radical reactions. The application methods led inaccessible classical associated with metal carbenes. most cases, act sources but can also serve acceptors. Importantly, described processes operate under mild, practical conditions. This Review describes this subfield compound chemistry, particularly focusing on advancements.

Language: Английский

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