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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Strain-Release Photocatalysis

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(38), P. 20716 - 20732

Published: Sept. 15, 2023

The concept of strain in organic compounds is as old modern chemistry and was initially introduced to justify the synthetic setbacks along synthesis small ring systems (pars construens strain). In last decades, chemists have developed an arsenal strain-release reactions destruens strain) which can generate─with significant driving force─rigid aliphatic that act three-dimensional alternatives (hetero)arenes. Photocatalysis added additional dimension processes by leveraging energy photons create chemical complexity under mild conditions. This perspective presents latest advancements photocatalysis─with emphases on mechanisms, catalytic cycles, current limitations─the unique architectures be produced, possible future directions.

Language: Английский

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Recent advances of visible-light photocatalysis in the functionalization of organic compounds

Journal of Photochemistry and Photobiology C Photochemistry Reviews, Journal Year: 2022, Volume and Issue: 50, P. 100488 - 100488

Published: Feb. 2, 2022

Language: Английский

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Aroyl Fluorides as Bifunctional Reagents for Dearomatizing Fluoroaroylation of Benzofurans

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(16), P. 7072 - 7079

Published: March 22, 2022

The 2,3-dihydrobenzofuran scaffold is widely found in natural products and biologically active compounds. Herein, dearomatizing 2,3-fluoroaroylation of benzofurans with aroyl fluorides as bifunctional reagents to access 2,3-difunctionalized dihydrobenzofurans reported. reaction that occurs by cooperative NHC/photoredox catalysis provides 3-aroyl-2-fluoro-2,3-dihydrobenzofurans moderate good yield high diastereoselectivity. Cascades proceed via radical/radical cross-coupling a benzofuran radical cation generated the photoredox cycle neutral ketyl formed through NHC cycle. redox-neutral transformation exhibits broad substrate scope functional group compatibility. With anhydrides reagents, aroyloxyacylation achieved strategy can also be applied

Language: Английский

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Oxidative Addition of Aryl Halides to a Ni(I)-Bipyridine Complex

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(12), P. 5575 - 5582

Published: March 17, 2022

The oxidative addition of aryl halides to bipyridine- or phenanthroline-ligated nickel(I) is a commonly proposed step in nickel catalysis. However, there scarcity complexes this type that both are well-defined and undergo with halides, hampering organometallic studies process. We report the synthesis Ni(I) complex, [(CO2Etbpy)NiICl]4 (1). Its solution-phase speciation characterized by significant population monomer redox equilibrium can be perturbed π-acceptors σ-donors. 1 reacts readily bromides, mechanistic consistent pathway proceeding through an initial → Ni(III) form species. Such process was demonstrated stoichiometrically for first time, affording structurally complex.

Language: Английский

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Late-Stage C–H Functionalization of Azines

Chemical Reviews, Journal Year: 2023, Volume and Issue: 123(12), P. 7655 - 7691

Published: May 3, 2023

Azines, such as pyridines, quinolines, pyrimidines, and pyridazines, are widespread components of pharmaceuticals. Their occurrence derives from a suite physiochemical properties that match key criteria in drug design is tunable by varying their substituents. Developments synthetic chemistry, therefore, directly impact these efforts, methods can install various groups azine C–H bonds particularly valuable. Furthermore, there growing interest late-stage functionalization (LSF) reactions focus on advanced candidate compounds often complex structures with multiple heterocycles, functional groups, reactive sites. Because factors electron-deficient nature the effects Lewis basic N atom, distinct arene counterparts, application LSF contexts difficult. However, have been many significant advances reactions, this review will describe progress, much which has occurred over past decade. It possible to categorize radical addition processes, metal-catalyzed activation transformations occurring via dearomatized intermediates. Substantial variation reaction within each category indicates both rich reactivity heterocycles creativity approaches involved.

Language: Английский

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Automated self-optimization, intensification, and scale-up of photocatalysis in flow

Science, Journal Year: 2024, Volume and Issue: 383(6681)

Published: Jan. 25, 2024

The optimization, intensification, and scale-up of photochemical processes constitute a particular challenge in manufacturing environment geared primarily toward thermal chemistry. In this work, we present versatile flow-based robotic platform to address these challenges through the integration readily available hardware custom software. Our open-source combines liquid handler, syringe pumps, tunable continuous-flow photoreactor, inexpensive Internet Things devices, an in-line benchtop nuclear magnetic resonance spectrometer enable automated, data-rich optimization with closed-loop Bayesian strategy. A user-friendly graphical interface allows chemists without programming or machine learning expertise easily monitor, analyze, improve photocatalytic reactions respect both continuous discrete variables. system's effectiveness was demonstrated by increasing overall reaction yields improving space-time compared those previously reported processes.

Language: Английский

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Late-stage Functionalization for Improving Drug-like Molecular Properties

Chemical Reviews, Journal Year: 2023, Volume and Issue: 123(13), P. 8127 - 8153

Published: June 7, 2023

The development of late-stage functionalization (LSF) methodologies, particularly C–H functionalization, has revolutionized the field organic synthesis. Over past decade, medicinal chemists have begun to implement LSF strategies into their drug discovery programs, allowing for process become more efficient. Most reported applications drugs and drug-like molecules been rapidly diversify screening libraries explore structure–activity relationships. However, there a growing trend toward use methodologies as an efficient tool improving molecular properties promising candidates. In this review, we comprehensively reviewed recent progress in emerging area. Particular emphasis is placed on case studies where multiple techniques were implemented generate library novel analogues with improved properties. We critically analyzed current scope improve commented how believe can transform future. Overall, aim provide comprehensive survey tools efficiently properties, anticipating its continued uptake programs.

Language: Английский

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Elucidating the Mechanism of Excited-State Bond Homolysis in Nickel–Bipyridine Photoredox Catalysts

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(14), P. 6516 - 6531

Published: March 30, 2022

Ni 2,2'-bipyridine (bpy) complexes are commonly employed photoredox catalysts of bond-forming reactions in organic chemistry. However, the mechanisms by which they operate still under investigation. One potential mode catalysis is via entry into Ni(I)/Ni(III) cycles, can be made possible light-induced, excited-state Ni(II)-C bond homolysis. Here, we report experimental and computational analyses a library Ni(II)-bpy aryl halide complexes, Ni(Rbpy)(R'Ph)Cl (R = MeO, t-Bu, H, MeOOC; R' CH3, OMe, F, CF3), to illuminate mechanism At given excitation wavelengths, photochemical homolysis rate constants span 2 orders magnitude across these structures correlate linearly with Hammett parameters both bpy ligands, reflecting structural control over key metal-to-ligand charge-transfer (MLCT) ligand-to-metal (LMCT) energy surfaces (PESs). Temperature- wavelength-dependent investigations reveal moderate barriers (ΔH‡ ∼ 4 kcal mol-1) minimum threshold (∼55 mol-1, 525 nm), respectively. Correlations electronic structure calculations further support repulsive triplet PESs featuring critical aryl-to-Ni LMCT lead rupture. Structural provides rational approach utilize photonic leverage processes synthetic

Language: Английский

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General access to cubanes as benzene bioisosteres

Nature, Journal Year: 2023, Volume and Issue: 618(7965), P. 513 - 518

Published: April 4, 2023

Language: Английский

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