A General Organocatalytic System for Electron Donor–Acceptor Complex Photoactivation and Its Use in Radical Processes

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(31), P. 12304 - 12314

Published: July 28, 2021

We report herein a modular class of organic catalysts that, acting as donors, can readily form photoactive electron donor-acceptor (EDA) complexes with variety radical precursors. Excitation visible light generates open-shell intermediates under mild conditions, including nonstabilized carbon radicals and nitrogen-centered radicals. The nature the commercially available xanthogenate dithiocarbamate anion organocatalysts offers versatile EDA complex catalytic platform for developing mechanistically distinct reactions, encompassing redox-neutral net-reductive processes. Mechanistic investigations, by means quantum yield determination, established that closed cycle is operational all developed processes, highlighting ability to turn over iteratively drive every cycle. also demonstrate how catalysts' stability method's high functional group tolerance could be advantageous direct functionalization abundant groups, aliphatic carboxylic acids amines, applications in late-stage elaboration biorelevant compounds enantioselective catalysis.

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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Sustainable Thioetherification via Electron Donor–Acceptor Photoactivation Using Thianthrenium Salts

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(22)

Published: March 16, 2022

Abstract The synthesis of sulfides has been widely studied because this functional subunit is prevalent in biomolecules and pharmaceuticals, as well being a useful synthetic platform for further elaboration. Thus, various methods to build C−S bonds have developed, but typically they require the use precious metals or harsh conditions. Electron donor–acceptor (EDA) complex photoactivation strategies emerged versatile sustainable ways achieve bond formation, avoiding challenges associated with previous methods. This work describes an open‐to‐air, photoinduced, site‐selective C−H thioetherification from readily available reagents via EDA formation that tolerates wide range different groups. Moreover, C(sp 2 )−halogen remain intact using protocol, allowing late‐stage installation sulfide motif bioactive scaffolds, while yet modification through more traditional C−X cleavage protocols. Additionally, mechanistic investigations support envisioned scenario.

Language: Английский

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A general electron donor–acceptor complex for photoactivation of arenes via thianthrenation

Chemical Science, Journal Year: 2022, Volume and Issue: 13(19), P. 5659 - 5666

Published: Jan. 1, 2022

General photoactivation of EDA complexes between arylsulfonium salts and 1,4-diazabicyclo[2.2.2]octane was discovered. This practical mode enables the generation aryl radicals for C–H functionalization arenes.

Language: Английский

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Overcoming Limitations in Decarboxylative Arylation via Ag–Ni Electrocatalysis

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(38), P. 17709 - 17720

Published: Sept. 15, 2022

A useful protocol for achieving decarboxylative cross-coupling (DCC) of redox-active esters (RAE, isolated or generated in situ) and halo(hetero)arenes is reported. This pragmatically focused study employs a unique Ag-Ni electrocatalytic platform to overcome numerous limitations that have plagued this strategically powerful transformation. In its optimized form, coupling partners can be combined surprisingly simple way: open the air, using technical-grade solvents, an inexpensive ligand Ni source, substoichiometric AgNO3, proceeding at room temperature with commercial potentiostat. Most importantly, all results are placed into context by benchmarking state-of-the-art methods. Applications presented simplify synthesis rapidly enable access challenging chemical space. Finally, adaptation multiple scale regimes, ranging from parallel milligram-based decagram recirculating flow presented.

Language: Английский

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Decarboxylative Cross-Coupling: A Radical Tool in Medicinal Chemistry

ACS Medicinal Chemistry Letters, Journal Year: 2022, Volume and Issue: 13(9), P. 1413 - 1420

Published: Aug. 10, 2022

Carboxylic acids, the most versatile and ubiquitous diversity input used in medicinal chemistry for canonical polar bond constructions such as amide synthesis, can now be employed a fundamentally different category of reaction to make C-C bonds by harnessing power radicals. This outlook serves user-guide aid practitioners both design syntheses that leverage simplifying this disconnection precise tactics enable them. Taken together, emerging area holds potential rapidly accelerate access chemical space value modern chemistry.

Language: Английский

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EDA photochemistry: Mechanistic investigations and future opportunities

Chem, Journal Year: 2023, Volume and Issue: 9(9), P. 2390 - 2415

Published: July 18, 2023

Language: Английский

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Tetrachlorophthalimides as Organocatalytic Acceptors for Electron Donor–Acceptor Complex Photoactivation

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(20), P. 8914 - 8919

Published: May 13, 2022

Excitation of photoactive electron donor-acceptor (EDA) complexes is an effective way to generate radicals. Applications in a catalytic regime typically use donors. Herein, we report that readily available electron-poor tetrachlorophthalimides can act as organocatalytic acceptors trigger the formation EDA with variety radical precursors not amenable previous methods. visible light generates carbon radicals under mild conditions. The versatility this complex platform allowed us develop mechanistically distinct reactions, including combination cobalt-based system. Quantum yield measurements established closed cycle operational, which hints at ability turn over and govern each cycle.

Language: Английский

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Modular and Facile Access to Chiral α-Aryl Phosphates via Dual Nickel- and Photoredox-Catalyzed Reductive Cross-Coupling

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(9), P. 3989 - 3997

Published: Feb. 22, 2022

Chiral phosphine-containing skeletons are important motifs in bioactive natural products, pharmaceuticals, chiral catalysts, and ligands. Herein, we report a general modular platform to access α-aryl phosphorus compounds via Ni/photoredox-catalyzed enantioconvergent reductive cross-coupling between α-bromophosphates aryl iodides. This dual catalytic regime exhibited high efficiency good functional group compacity. A wide variety of substrates bearing diverse set groups could be converted into phosphates excellent yields enantioselectivities. The utility the method was also demonstrated by development new phosphine ligand synthesis enzyme inhibitor derivatives. detailed mechanistic studies supported radical chain process revealed unique distinction compared with traditional cross-coupling.

Language: Английский

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Diversification of Glycosyl Compounds via Glycosyl Radicals

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(38)

Published: June 7, 2023

Glycosyl radical functionalization is one of the central topics in synthetic carbohydrate chemistry. Recent advances metal-catalyzed cross-coupling chemistry and metallaphotoredox catalysis provided powerful platforms for glycosyl diversification. In particular, discovery new precursors conjunction with these advanced reaction technologies have significantly expanded space compound synthesis. this Review, we highlight most recent progress area starting from 2021, reports included will be categorized based on different types better clarity.

Language: Английский

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