Photoredox-Catalyzed Alkylarylation of N-Aryl Bicyclobutyl Amides with α-Carbonyl Alkyl Bromides: Access to 3-Spirocyclobutyl Oxindoles

Organic Letters, Год журнала: 2024, Номер 26(10), С. 2073 - 2078

Опубликована: Март 6, 2024

A visible-light-induced radical alkylarylation of N-aryl bicyclobutyl amides with α-carbonyl alkyl bromides for the synthesis functionalized 3-spirocyclobutyl oxindoles is described in which β-selective addition to forms a key intermediate followed by interception intrinsic arene functional group. This approach can be applicable wide range bromides, including primary, secondary, and tertiary α-bromoalkyl esters, ketones, nitriles, nitro compounds.

Язык: Английский

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Visible‐Light‐Induced Domino Cyclization to Access Pyrido[2,3‐d]pyrimidine‐2,4‐diones via a Radical‐Polar Crossover Reaction

Chinese Journal of Chemistry, Год журнала: 2024, Номер 42(19), С. 2346 - 2350

Опубликована: Май 27, 2024

Comprehensive Summary Catalytic and green strategies for the synthesis of privileged scaffolds are synthetically appealing. We now report a radical‐polar crossover (RPC)‐enabled three‐component cyclization bromodifluoroalkyls with enaminones 6‐aminouraciles via visible‐light‐induced domino cyclization. The reaction exhibited broad substrate scope (> 40 examples) including complex molecules, which highlighted utility this strategy construction library bioactive analogs.

Язык: Английский

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Tunable vicinal, geminal diphosphorylation and C–N bond phosphorylation of enaminones toward divergent phosphorylated ketone derivatives

Chemical Communications, Год журнала: 2023, Номер 59(42), С. 6383 - 6386

Опубликована: Янв. 1, 2023

The tunable reactions of enaminones with phosphine oxides/phosphonates in the form vicinal- and geminal diphosphorylation, C–N bond phosphorylation have been developed, providing new methods for synthesis divergent phosphorylated molecules.

Язык: Английский

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Photoinduced Cascade Difluoroalkylative Ring-Opening of Vinyl Cyclopropanes

Organic Letters, Год журнала: 2023, Номер 25(16), С. 2857 - 2862

Опубликована: Апрель 14, 2023

Here, we report a facile and efficient method for the difluoroalkylation of vinyl cyclopropanes (VCPs) using visible-light organophotoredox catalysis. This strategy exploits interplay α-amino alkyl radical-mediated halogen-atom transfer (XAT) reaction. The broad substrate scope, excellent functional group compatibility, operational simplicity, inexpensive CF2 precursors, high efficiency make this protocol promising cost-efficient synthesis allylic difluoroalkylated derivatives.

Язык: Английский

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Divergent functionalization of alkenes enabled by photoredox activation of CDFA and α-halo carboxylic acids

Chemical Science, Год журнала: 2024, Номер 15(27), С. 10659 - 10667

Опубликована: Янв. 1, 2024

The direct activation of α-halo carboxylic acids using visible-light-mediated photoredox catalysis facilitates the formation bifunctional radical intermediates, allowing reactivity toward olefins to be fine-tuned by varying solvent system.

Язык: Английский

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Difluoroalkylation/Lactonization of Alkenes with BrCF₂CO₂K via Photoredox Catalysis: Access to α,α‐Difluoro‐γ‐lactones^†

Chinese Journal of Chemistry, Год журнала: 2023, Номер 41(21), С. 2819 - 2824

Опубликована: Июнь 25, 2023

Comprehensive Summary Due to its unique electronic properties, the difluoromethylene group (CF 2 ) has served as a valuable unity in design of biologically active molecules. Since γ‐lactones display broad range biological α,α‐difluoro‐γ‐lactones may exhibit unexpected activities, and thus their synthesis received increasing attention. Traditional synthetic methods suffer from tedious multi‐ step processes, very few effective have been reported recently. Herein, we describe difunctionalization alkenes with BrCF CO K under photoredox catalysis use boron‐Lewis acid for access α,α‐difluoro‐γ‐lactones. In this transformation, alkene substrates used reagents, including acid, PhB(OH) or BF 3 ·THF, are cheap widely available. High efficiency atom economy make protocol attractive.

Язык: Английский

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Phenothiazine Sulfoxides as Active Photocatalysts for the Synthesis of γ-Lactones

Journal of the American Chemical Society, Год журнала: 2025, Номер unknown

Опубликована: Апрель 2, 2025

N-substituted phenothiazines are prominent and highly effective organic photoredox catalysts, particularly known for their strong reducing capabilities. Despite wide utility, the closely related phenothiazine sulfoxides, which easily form upon oxidation, have been largely overlooked not explored in context of photocatalysis. Herein, we describe discovery application N-phenylphenothiazine sulfoxide as a photocatalyst reductive activation cyclic malonyl peroxides, giving access to complex γ-lactones starting from simple olefins. Detailed mechanistic studies were carried out better understand situ formation active catalyst species commercial precursor, well interconversion photocatalytic mechanism γ-lactone products. Specifically, employed broad range tools, including time-resolved spectroscopy, spectroelectrochemistry, transient UV-vis absorption voltammetry, isotopic labeling, radical trapping experiments, NMR density functional theory (DFT) calculations. The synthetic utility this protocol is demonstrated substrate scope study, highlighting facile spirocyclic γ-lactones, widely recognized biological importance.

Язык: Английский

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Base-Dependent Divergent Carbodifluoroalkylation and Halodifluoroalkylation of Alkenes under Visible-Light Irradiation

The Journal of Organic Chemistry, Год журнала: 2024, Номер 89(18), С. 13457 - 13471

Опубликована: Сен. 3, 2024

Organic molecules containing a difluoroalkyl group are valuable and versatile chemicals because of their unique physicochemical biological properties. Accordingly, the development efficient practical difluoroalkylation for preparation these compounds is important attractive. Herein, we demonstrate photoredox-catalyzed base-dependent selective carbodifluoroalkylation halodifluoroalkylation alkenes using readily available 2-(allyloxy)arylaldehydes [or 2-(allylamino)arylaldehydes] XCF

Язык: Английский

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Thermally Activated Geometrical Regioselective E→Z Isomerization‐Enabled Cascade Sequences of Conjugated Dienals: Experimental and DFT Studies

Chemistry - A European Journal, Год журнала: 2023, Номер 29(63)

Опубликована: Авг. 9, 2023

The geometrical regioselective E→Z isomerization of a conjugated alkene under thermal activation pose challenge due to microscopic reversibility. Herein we report that such reversibility issues can be circumvented by integrating with subsequent cyclization cascade, particularly in the absence commonly employed light, acids, or metal-catalysts. Thus, linearly dienals mixture toluene-alcohol (2 : 1) solvents only alcohol at 60-70 °C converted γ-alkoxybutenolides moderate good yields. intermediary 2Z,4E-isomer isolated, which includes first example isolating product conditions. Density functional theory (DFT) studies have been shed light on feasibility and ensuing cascade sequences. It has observed 2E,4E→2Z,4E dienal is thermodynamically facile (ΔG <0) process. Structural elucidation further reveals presence certain charge transfer non-covalent interaction may primary reasons for enhanced stability 2Z,4E-isomer. thermodynamic plausibility reaction from Z-isomer anticipated polar protic solvent (here MeOH) also explicated. Out two probable pathways, "hemiacetal pathway" involving relay proton kinetically more feasible diminished barrier than "conjugate addition pathway".

Язык: Английский

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10-Phenylphenothiazine-Organophotocatalyzed Bromo-Perfluoroalkylation of Unactivated Olefins

The Journal of Organic Chemistry, Год журнала: 2024, Номер 89(10), С. 7084 - 7094

Опубликована: Апрель 25, 2024

In this study, we have developed a smooth metal-free visible-light-induced bromo-perfluoroalkylation of unactivated olefins with the aid 10-phenylphenothiazine (PTH) as an organic photoredox catalyst. The reaction is 100% atom-economic redox-neutral and proceeds stoichiometric amounts olefin perfluoroalkyl bromide. To show potential these unexplored motifs, carried out various postfunctionalizations taking advantage bromine atom, including gram-scale experiments.

Язык: Английский

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