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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Metallaphotoredox-enabled deoxygenative arylation of alcohols

Nature, Journal Year: 2021, Volume and Issue: 598(7881), P. 451 - 456

Published: Aug. 31, 2021

Language: Английский

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Reductive Cross-Coupling of Unreactive Electrophiles

Accounts of Chemical Research, Journal Year: 2022, Volume and Issue: 55(17), P. 2491 - 2509

Published: Aug. 11, 2022

ConspectusTransition-metal-catalyzed reductive coupling of electrophiles has emerged as a powerful tool for the construction molecules. While major achievements have been made in field cross-couplings between organic halides and pseudohalides, an increasing number reports demonstrates reactions involving more readily available, low-cost, stable, but unreactive electrophiles. This account summarizes recent results our laboratory focusing on this topic. These findings typically include deoxygenative C–C alcohols, alkylation alkenyl acetates, C–Si chlorosilanes, C–Ge chlorogermanes.The alcohols with is synthetically appealing, potential chemistry remains to be disclosed. Our initial study focused reaction allylic aryl bromides by combination nickel Lewis acid catalysis. method offers selectivity that opposite classic Tsuji–Trost reactions. Further investigation benzylic led foundation dynamic kinetic cross-coupling strategy applications nickel-catalyzed arylation cobalt-catalyzed enantiospecific alkenylation alcohols. The titanium catalysis was later established produce carbon radicals directly from unactivated tertiary via C–OH cleavage. development their fragments delivers new methods all-carbon quaternary centers. shown high functionalization leaving primary secondary intact. Alkenyl acetates are inexpensive, environmentally friendly considered most attractive reagents. benzyl ammoniums alkyl mild approaches conversion ketones into aliphatic alkenes.Extensive studies enabled us extend cross-electrophile silicon germanium chemistry. harness ready availability chlorosilanes chlorogermanes suffer challenge low reactivity toward transition metals. Under catalysis, broad range couple well vinyl- hydrochlorosilanes. use partners formation functionalized alkylsilanes. seems less substrate-dependent, various common aryl, alkenyl, In general, functionalities such Grignard-sensitive groups (e.g., acid, amide, alcohol, ketone, ester), acid-sensitive ketal THP protection), fluoride chloride, bromide, tosylate mesylate, silyl ether, amine tolerated. provide access organosilicon organogermanium compounds, some which challenging obtain otherwise.

Language: Английский

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Nontraditional Fragment Couplings of Alcohols and Carboxylic Acids: C(sp³)–C(sp³) Cross-Coupling via Radical Sorting

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(14), P. 6185 - 6192

Published: March 30, 2022

Alcohols and carboxylic acids are among the most commercially abundant, synthetically versatile, operationally convenient functional groups in organic chemistry. Under visible light photoredox catalysis, these native synthetic handles readily undergo radical activation, resulting open-shell intermediates can subsequently participate transition metal catalysis. In this report, we describe C(sp3)–C(sp3) cross-coupling of alcohols through dual combination N-heterocyclic carbene (NHC)-mediated deoxygenation hypervalent iodine-mediated decarboxylation. This mild practical Ni-catalyzed radical-coupling protocol was employed to prepare a wide array alkyl–alkyl cross-coupled products, including highly congested quaternary carbon centers from corresponding tertiary or acids. We demonstrate applications methodology alcohol C1-alkylation formal homologation, as well late-stage functionalization drugs, natural biomolecules.

Language: Английский

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Using Data Science To Guide Aryl Bromide Substrate Scope Analysis in a Ni/Photoredox-Catalyzed Cross-Coupling with Acetals as Alcohol-Derived Radical Sources

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(2), P. 1045 - 1055

Published: Jan. 5, 2022

Ni/photoredox catalysis has emerged as a powerful platform for C(sp2)–C(sp3) bond formation. While many of these methods typically employ aryl bromides the C(sp2) coupling partner, variety aliphatic radical sources have been investigated. In principle, reactions enable access to same product scaffolds, but it can be hard discern which method because nonstandardized sets are used in scope evaluation. Herein, we report Ni/photoredox-catalyzed (deutero)methylation and alkylation halides where benzaldehyde di(alkyl) acetals serve alcohol-derived sources. Reaction development, mechanistic studies, late-stage derivatization biologically relevant chloride, fenofibrate, presented. Then, describe integration data science techniques, including DFT featurization, dimensionality reduction, hierarchical clustering, delineate diverse succinct collection that is representative chemical space substrate class. By superimposing examples from published on this space, identify areas sparse coverage high versus low average yields, enabling comparisons between prior art new method. Additionally, demonstrate systematically selected quantify population-wide reactivity trends reveal possible functional group incompatibility with supervised machine learning.

Language: Английский

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Facile and general electrochemical deuteration of unactivated alkyl halides

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

Published: June 30, 2022

Abstract Herein, a facile and general electroreductive deuteration of unactivated alkyl halides (X = Cl, Br, I) or pseudo-halides OMs) using D 2 O as the economical deuterium source was reported. In addition to primary secondary halides, sterically hindered tertiary chlorides also work very well, affording target deuterodehalogenated products with excellent efficiency incorporation. More than 60 examples are provided, including late-stage dehalogenative natural products, pharmaceuticals, their derivatives, all incorporation (up 99% D), demonstrating potential utility developed method in organic synthesis. Furthermore, does not require external catalysts tolerates high current, showing possible use industrial applications.

Language: Английский

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Electroreductive Cross‐Electrophile Coupling (eXEC) Reactions

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(45)

Published: June 16, 2023

Abstract Electrochemistry utilizes electrons as a potent, controllable, and traceless alternative to chemical oxidants or reductants, typically offers more sustainable option for achieving selective organic synthesis. Recently, the merger of electrochemistry with readily available electrophiles has been recognized viable increasingly popular methodology efficiently constructing challenging C−C C‐heteroatom bonds in manner complex molecules. In this mini‐review, we have systematically summarized most recent advances electroreductive cross‐electrophile coupling (eXEC) reactions during last decade. Our focus on electrophiles, including aryl alkyl (pseudo)halides, well small molecules such CO 2 , SO D O.

Language: Английский

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Elucidating electron-transfer events in polypyridine nickel complexes for reductive coupling reactions

Nature Catalysis, Journal Year: 2023, Volume and Issue: 6(3), P. 244 - 253

Published: March 9, 2023

Language: Английский

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Nickel/biimidazole-catalyzed electrochemical enantioselective reductive cross-coupling of aryl aziridines with aryl iodides

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

Published: April 22, 2023

Here, we report an asymmetric electrochemical organonickel-catalyzed reductive cross-coupling of aryl aziridines with iodides in undivided cell, affording β-phenethylamines good to excellent enantioselectivity broad functional group tolerance. The combination cyclic voltammetry analysis the catalyst reduction potential as well electrode study provides a convenient route for reaction optimization. Overall, high efficiency this method is credited electroreduction-mediated turnover nickel instead metal reductant-mediated turnover. Mechanistic studies suggest radical pathway involved ring opening aziridines. statistical serves compare different design requirements photochemically and electrochemically mediated reactions under type mechanistic manifold.

Language: Английский

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Toward effective electrocatalytic C–N coupling for the synthesis of organic nitrogenous compounds using CO₂ and biomass as carbon sources

SusMat, Journal Year: 2023, Volume and Issue: 3(6), P. 781 - 820

Published: Dec. 1, 2023

Abstract Thermochemical conversion of fossil resources into fuels, chemicals, and materials has rapidly increased atmospheric CO 2 levels, hindering global efforts toward achieving carbon neutrality. With the increasing push for sustainability, utilizing electrochemical technology to transform or biomass value‐added chemicals close cycle with sustainable energy sources represents a promising strategy. Expanding scope electrosynthesis is prerequisite electrification chemical manufacturing. To this end, constructing C─N bond considered priority. However, systematic review electrocatalytic processes building bonds using as not available. Accordingly, highlights research progress in organic nitrogen compounds from by coupling reactions view catalytic materials, focusing on enlightenment traditional catalysis understanding basis coupling. The possibility electrocatalysis also examined standpoints activation substrates, site, mechanism, inhibition hydrogen evolution reaction (HER). Finally, challenges prospects improved efficiency selectivity future development are discussed.

Language: Английский

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