Organothianthrenium salts: synthesis and utilization

Chemical Science, Год журнала: 2022, Номер 13(46), С. 13690 - 13707

Опубликована: Янв. 1, 2022

This review summarizes the synthesis of diverse organothianthrenium salts from various precursors and their applications in organic to forge new C–C, C–H C–heteroatom bonds by C–S bond cleavage with different mechanistic considerations.

Язык: Английский

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Electrophotochemical Ce-Catalyzed Ring-Opening Functionalization of Cycloalkanols under Redox-Neutral Conditions: Scope and Mechanism

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(30), С. 13895 - 13902

Опубликована: Июль 21, 2022

Selective cleavage and functionalization of C–C bonds in alcohols is gaining increasing interest organic synthesis biomass conversion. In particular, the development redox-neutral catalytic methods with cheap catalysts clean energy utmost interest. this work, we report a versatile method for ring-opening cycloalkanols by electrophotochemical (EPC) cerium (Ce) catalysis. The EPC-Ce-enabled catalysis allows different ring sizes to be cleaved while tolerating broad range functional groups. Notably, presence chloride as counteranion electrolyte, protocol selectively leads formation C–CN, C–C, C–S, or C–oxime instead C–halide bond after β-scission. A preliminary mechanistic investigation indicates that redox-active Ce catalyst can tuned electro-oxidation photo-reduction, thus avoiding use an external oxidant. Spectroscopic characterizations (cyclic voltammetry, UV–vis, electron paramagnetic resonance, X-ray absorption fine structure) suggest Ce(III)/Ce(IV) pathway transformation, which Ce(IV)-alkoxide involved.

Язык: Английский

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Synthesis of Cyclopropenols Enabled by Visible‐Light‐Induced Organocatalyzed [2+1] Cyclization

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(10)

Опубликована: Янв. 7, 2022

Although the synthesis of common cyclopropenes has been well studied, access to cyclopropenols is rather limited. Herein, we report first α-trifluoromethylated via 2+1 cycloaddition reactions between alkynes and trifluoroacylsilanes, enabled by visible-light-induced organocatalysis. The novel ambiphilic donor-acceptor carbenes derived from trifluoroacetylsilanes reacted efficiently with both activated non-activated alkynes. reaction features simple operation, mild conditions, broad substrate scope good functional group tolerance. synthetic potential highlighted gram-scale cyclopropanols through combination cyclization high diastereoselective hydrogenation in one pot.

Язык: Английский

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Palladium-Catalyzed Siloxycyclopropanation of Alkenes Using Acylsilanes

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(3), С. 1099 - 1105

Опубликована: Янв. 12, 2022

Currently, catalytically transferable carbenes are limited to electron-deficient and neutral derivatives, electron-rich bearing an alkoxy group (i.e., Fischer-type carbenes) cannot be used in catalytic cyclopropanation because of the lack appropriate carbene precursors. We report herein that acylsilanes can serve as a source under palladium catalysis, enabling range alkenes. This reactivity profile is sharp contrast metal-free siloxycarbenes, which unreactive toward normal The resulting siloxycyclopropanes valuable homoenolate equivalents, allowing rapid access elaborate β-functionalized ketones.

Язык: Английский

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Carbon–Carbon Bond Cleavage for Late-Stage Functionalization

Chemical Reviews, Год журнала: 2023, Номер 123(22), С. 12313 - 12370

Опубликована: Ноя. 9, 2023

Late-stage functionalization (LSF) introduces functional group or structural modification at the final stage of synthesis natural products, drugs, and complex compounds. It is anticipated that late-stage would improve drug discovery's effectiveness efficiency hasten creation various chemical libraries. Consequently, products a productive technique to produce product derivatives, which significantly impacts biology development. Carbon-carbon bonds make up fundamental framework organic molecules. Compared with carbon-carbon bond construction, activation can directly enable molecular editing (deletion, insertion, atoms groups atoms) provide more efficient accurate synthetic strategy. However, selective unstrained still one most challenging projects in synthesis. This review encompasses strategies employed recent years for cleavage by explicitly focusing on their applicability functionalization. expands current discourse reactions providing comprehensive overview types bonds. includes C-C(sp), C-C(sp2), C-C(sp3) single bonds; double triple bonds, focus catalysis transition metals organocatalysts. Additionally, specific topics, such as ring-opening processes involving three-, four-, five-, six-membered rings, are discussed, exemplar applications these techniques showcased context bioactive molecules discovery. aims shed light advancements field propose potential avenues future research realm

Язык: Английский

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Carbon-carbon triple bond cleavage and reconstitution to achieve aryl amidation using nitrous acid esters

Nature Communications, Год журнала: 2025, Номер 16(1)

Опубликована: Янв. 24, 2025

C–C bond cleavage and recombination provide an efficient strategy for the modification reconstruction of molecule structures. Herein, we present a method achieving amidation aryl C(sp2)–H through triple with involvement nitrous acid esters. This marks instance precise controlled stepwise bond, offering fresh perspective such bonds. Nitrous ester serves as both radical source hydrogen atom transfer (HAT) reagent to functionalize utilize two carbon atoms bond. The alkoxy captures from or N-hydroxyl induce 1,3-oxygen migration, which is crucial subsequent molecular authors report achieve bonds by participation

Язык: Английский

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Small rings in the bigger picture: ring expansion of three- and four-membered rings to access larger all-carbon cyclic systems

Chemical Society Reviews, Год журнала: 2021, Номер 50(13), С. 7513 - 7538

Опубликована: Янв. 1, 2021

Ring-expansion of strained small-size rings to forge larger all-carbon ones, allows a rapid build-up molecular complexity.

Язык: Английский

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Diastereoselective Transfer of Tri(di)fluoroacetylsilanes‐Derived Carbenes to Alkenes

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(25)

Опубликована: Апрель 13, 2022

Stereoselective cyclopropanation reaction of alkenes is usually achieved by metal complexes via singlet-metal-carbene intermediates. However, previous transition-metal-catalyzed with acylsilanes afforded low diastereoselectivity. Herein, we report the first visible-light-induced transition-metal-free terminal trifluoroacetylsilanes and difluoroacetylsilanes. Both aromatic aliphatic as well electron-deficient are suitable substrates for highly cis-selective [2+1] cyclization reaction. A combination experimental computational studies identified triplet carbenes being key intermediates in this transformation. The gram scale late-stage functionalization demonstrated synthetic potential strategy.

Язык: Английский

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Intramolecular photochemical [2 + 1]-cycloadditions of nucleophilic siloxy carbenes

Chemical Science, Год журнала: 2022, Номер 13(11), С. 3273 - 3280

Опубликована: Янв. 1, 2022

Visible light induced singlet nucleophilic carbenes undergo rapid [2 + 1]-cycloaddition with tethered olefins to afford unique bicyclo[3.1.0]hexane and bicyclo[4.1.0]heptane scaffolds. This cyclopropanation process requires only visible irradiation proceed, circumventing the use of exogenous (photo)catalysts, sensitisers or additives showcases a vastly underexplored mode reactivity for in chemical synthesis. The discovery additional transformations including cyclopropanation/retro-Michael/Michael cascade chromanones photochemical C-H insertion reaction are also described.

Язык: Английский

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Site-Divergent Alkenyl C–H Fluoroallylation of Olefins Enabled by Tunable Rhodium Catalysis

ACS Catalysis, Год журнала: 2022, Номер 12(15), С. 8857 - 8867

Опубликована: Июль 10, 2022

The unique properties of the fluorine-containing compounds and their widespread applications raise demand for dependable synthetic methods on precise introduction substituents into organic molecules. Herein, a site-divergent fluoroallylation olefins that can incorporate fluoroallyl motif different alkenyl C–H sites is disclosed. gem-Difluorinated cyclopropanes are employed as sources via rhodium-catalyzed C–C bond activation. This strategy provide two regioisomeric fluorinated skipped dienes in good yields with excellent site-selectivity. resulting products serve useful building blocks to access various molecules isosteric β, γ-unsaturated amides, which promising be exploited medicinal chemistry. Mechanistic studies revealed electronic property rhodium catalysts crucial controllable site-selectivity, providing more insights beyond methodology tuning selectivity metal catalysts.

Язык: Английский

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