Asymmetric Photoredox Catalytic Minisci-Type Reactions of α-Bromide Amides

Organic Letters, Год журнала: 2025, Номер 27(5), С. 1244 - 1249

Опубликована: Янв. 23, 2025

An asymmetric photoredox catalytic Minisci-type reaction between α-bromide amides and imine-containing azaarenes has been successfully developed. This catalyst system employs a chiral phosphoric acid alongside 3DPAFIPN as photosensitizer. The produces diverse array of valuable amides, featuring azaarene-substituted tertiary carbon stereocenters at the β-position, in high yields (up to 85%) good excellent enantioselectivities >99% enantiomeric excess (ee)). Importantly, this work marks first example radical addition simple utilizing radicals functionalized with electron-withdrawing carbonyl groups, which are conventionally considered unfavorable for such transformations, especially an enantioselective manner.

Язык: Английский

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Catalytic asymmetric photocycloaddition reactions mediated by enantioselective radical approaches

Chemical Society Reviews, Год журнала: 2025, Номер unknown

Опубликована: Янв. 1, 2025

The use of olefins in the construction cyclic compounds represents a powerful strategy for advancing pharmaceutical industry.

Язык: Английский

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Chiral Primary Amine-Catalyzed Asymmetric Photochemical Reactions of Pyridotriazoles with Boronic Acids to Access Triarylmethanes

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

Опубликована: Янв. 29, 2025

Imine-containing azaarene-based triarylmethanes are vital molecular motifs that prevalent in a wide array of bioactive compounds. Recognizing the limitations current synthetic methodologies─marked by scarcity examples and difficulties flexible functional group modulation─we have developed an efficient modular asymmetric photochemical strategy employing pyridotriazoles boronic acids as substrates. Utilizing novel chiral diamine-derived pyrroles primary amines catalysts, we successfully synthesized diverse range with high yields excellent enantioselectivities. This method not only exhibits broad substrate scope outstanding tolerance but also enables precise synthesis deuterated derivatives using inexpensive D2O deuterium source. Mechanistic studies reveal unusual 1,4-boron shift is critical step generating boronated enamine intermediate, while shedding light on potential enantiocontrol mechanisms facilitated catalyst.

Язык: Английский

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Photoinduced copper-catalysed deracemization of alkyl halides

Nature, Год журнала: 2025, Номер 640(8057), С. 107 - 113

Опубликована: Апрель 2, 2025

Язык: Английский

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Asymmetric copper-catalyzed hydrophosphinylation of ethynylazaarenes to access P-chiral 2-azaaryl-ethylphosphine oxides

Chemical Science, Год журнала: 2025, Номер unknown

Опубликована: Янв. 1, 2025

We report a cost-effective approach for the enantioselective hydrophosphinylation of ethynylazaarenes utilizing chiral copper catalytic platform. This strategy efficiently converts racemic secondary phosphine oxides (SPOs) into P-chiral tertiary (TPOs) bearing functionalized olefin substituents with azaarene moieties, achieving high yields and exceptional enantioselectivities. These adducts serve as crucial intermediates in development valuable 1,5-hybrid P,N-ligands. The facile introduction diverse additional carbon-centered chirality through transformation moiety effectively enhances enantioselectivity asymmetric metal catalysis compared to ligands exhibiting solely P-chirality. Mechanistic investigations reveal that interaction between Cu(i) complex azaarenes promotes kinetic resolution SPOs. robustness this method is further demonstrated by its ability incorporate deuterium atoms olefins, highlighting potential relevance pharmaceutical applications.

Язык: Английский

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Oxetane Cleavage Pathways in the Excited State: Photochemical Kinetic Resolution as an Approach to Enantiopure Oxetanes

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

Опубликована: Апрель 14, 2025

Chiral spirocyclic oxetanes [2-oxo-spiro(3H-indole-3,2'-oxetanes)] were subjected to irradiation in the presence of a chiral thioxanthone catalyst (5 mol %) at λ = 398 nm. An efficient kinetic resolution was observed, which led an enrichment one oxetane enantiomer as major (15 examples, 37-50% yield, 93-99% ee). The minor underwent decomposition, and decomposition products carefully analyzed. They arise from photocycloreversion (retro-Paternò-Büchi reaction) into carbonyl component olefin. cycloreversion offers two cleavage pathways depending on whether C-O bond scission or C-C occurs carbon atom. course this reaction elucidated by suite mechanistic, spectroscopic, quantum chemical methods. In absence catalyst, exclusively initial scission, leading formaldehyde tetrasubstituted olefin products. Time-resolved spectroscopy femtosecond/picosecond time scale, synthetic experiments, calculations suggest occur first excited singlet state (S1). sensitizer, triplet states are populated, (T1) is responsible for isatin 1,1-diarylethene scission. explained recruiting predominantly oxindole. A two-point hydrogen-bonding interaction recognition enantiomer, corroborated NMR titration studies calculations. Transient absorption nanosecond/microsecond scale allowed observing quenching either enantiomers with slight preference enantiomer. competing situation both present, energy transfer suppressed initially better-binding and─as progresses─by oxindole fragmentation blocking binding site catalyst.

Язык: Английский

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Deracemization of C(sp³)–H Arylated Carbonyl Compounds via Asymmetric Ion-Pairing Photoredox Catalysis

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

Опубликована: Апрель 17, 2025

Deracemization of C(sp3)-H arylated carbonyl compounds faces limitations in terms substrate scope. Through the photoactivation aryl group and stereocontrol generated arene radical cation via asymmetric ion-pairing catalysis, we are able to achieve deracemization at both enolizable unenolizable stereocenters. A diverse range α-, β-, γ-aryl ketones esters, including natural products medicinal derivatives, can be effectively converted into their enantiomers with high enantioselectivity. Mechanistic investigations through combined experimental computational studies suggest that reaction involves single-electron oxidation electron-rich groups, followed by a kinetic resolution resulting intermediates chiral phosphate anion. Deprotonation is identified as stereodetermining step, while stereoselective back electron transfer triplet-state quenching 3 Mes-Acr1+* may also affect enantioselectivity photostationary state.

Язык: Английский

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Photochemical Deracemization of Lactams with Deuteration Enabled by Dual Hydrogen Atom Transfer

Journal of the American Chemical Society, Год журнала: 2024, Номер unknown

Опубликована: Дек. 18, 2024

Photochemical deracemization has emerged as one of the most straightforward approaches to access highly enantioenriched compounds in recent years. While excited-state events such energy transfer, single electron and ligand-to-metal charge transfer have been leveraged promote stereoablation, relying on hydrogen atom which circumvent limitations imposed by triplet redox potential racemic substrates, remain underexplored. Conceptually, attractive method for tertiary stereocenter might be abstraction followed donation. However, implementing a strategy poses significant challenges, primarily because products are also reactive if chiral catalyst is unable differentiate between two enantiomers. Herein we report distinct dual photochemical δ- γ-lactams, achieving high enantioenrichment deuterium incorporation despite inherent reactivity products. Mechanistic studies reveal that benzophenone enables nonselective while tetrapeptide-derived thiol dictates enantioselectivity donation step. More importantly, pyridine-based alcohol was found play crucial roles facilitating well enhancing

Язык: Английский

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Synthesis of rigidified cyclohexanes enabled by visible-light-induced trifluoroacetylsilane-mediated [2+2] cycloaddition of cyclopropenes

Chinese Chemical Letters, Год журнала: 2024, Номер unknown, С. 110758 - 110758

Опубликована: Дек. 1, 2024

Язык: Английский

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Photocatalytic intermolecular dearomative cycloaddition of phenanthrenes and naphthalenes with excited gem-difluoroalkenes

Chem Catalysis, Год журнала: 2024, Номер unknown, С. 101200 - 101200

Опубликована: Дек. 1, 2024

Язык: Английский

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