Radical Hydrocarboxylation of Unactivated Alkenes via Photocatalytic Formate Activation

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(20), С. 10991 - 10997

Опубликована: Май 15, 2023

Herein we disclose a strategy to promote the hydrocarboxylation of unactivated alkenes using photochemical activation formate salts. We illustrate that an alternative initiation mechanism circumvents limitations prior approaches and enables this challenging substrate class. Specifically, found accessing requisite thiyl radical initiator without exogenous chromophore eliminates major byproducts have plagued attempts exploit similar reactivity for alkene substrates. This redox-neutral method is technically simple execute effective across broad range Feedstock alkenes, such as ethylene, are hydrocarboxylated at ambient temperature pressure. A series cyclization experiments indicate how described in report can be diverted by more complex processes.

Язык: Английский

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Oxetane Synthesis via Alcohol C–H Functionalization

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(29), С. 15688 - 15694

Опубликована: Июль 18, 2023

Oxetanes are strained heterocycles with unique properties that have triggered significant advances in medicinal chemistry. However, their synthesis still presents challenges limit the use of this class compounds practical applications. In Letter, we present a methodology introduces new synthetic disconnection to access oxetanes from native alcohol substrates. The generality approach is demonstrated by application late-stage functionalization chemistry, which further exploited develop single-step known bioactive steroid derivative previously required at least four steps available precursors.

Язык: Английский

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Shedding light on thermally-activated delayed fluorescence

Chemical Science, Год журнала: 2024, Номер 15(15), С. 5434 - 5450

Опубликована: Янв. 1, 2024

To exploit the applicative potential of TADF, several intertwined interactions must be understood, fully accounting for local environment.

Язык: Английский

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Alkene Thianthrenation Unlocks Diverse Cation Synthons: Recent Progress and New Opportunities

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(16)

Опубликована: Фев. 8, 2024

Oxidative alkene functionalization reactions are a fundamental class of complexity-building organic transformations. However, the majority established approaches rely on electrophilic reagents that limit diversity groups can be installed. Recent advances have new approach instead relies transformation alkenes into thianthrene-derived cationic electrophiles. These linchpin intermediates generated selectively and undergo diverse array mechanistically distinct with abundant nucleophiles. Taken together, this unlocks suite net oxidative transformations been elusive using conventional strategies. This Minireview describes these is organized around three synthons formally accessible from via thianthrenation: 1) alkenyl cations; 2) vicinal dications; 3) allyl cations. Throughout Minireview, we illustrate how thianthrenium salts address key limitations endemic to classic alkene-derived electrophiles highlight mechanistic origins distinctions wherever possible.

Язык: Английский

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Easy Access to Functionalized Indolines and Tetrahydroquinolines via a Photochemical Cascade Cyclization Reaction

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(21), С. 14521 - 14527

Опубликована: Май 14, 2024

Herein, the development of a light-mediated synthesis functionalized indolines and tetrahydroquinolines is reported. These structural motifs are considered as highly valuable targets, attributed to their widespread occurrence in pharmaceuticals natural products. The gold-mediated approach offers direct route yields up 81% under mild photochemical conditions. Thereby, easily accessible Boc-protected N-aryl-allylamine homoallylamine derivatives were reacted with sp3-hybridized haloalkanes an intermolecular cascade cyclization reaction. A broad scope substrates, including variety different substituents on aromatic backbone well various haloalkanes, could be utilized. Indoline derivatives, which position 2, also by applying ortho-allylic anilines. Moreover, synthetic appeal was demonstrated for total anti-inflammatory agent AN669 three reaction steps overall yield 64%.

Язык: Английский

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Enhancing Electron Donor–Acceptor Complex Photoactivation with a Stable Perylene Diimide Metal–Organic Framework

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

Опубликована: Янв. 27, 2025

Electron donor–acceptor complexes are commonly employed to facilitate photoinduced radical-mediated organic reactions. However, achieving these photochemical processes with catalytic amounts of donors or acceptors can be challenging, especially when aiming reduce catalyst loadings. Herein, we have unveiled a framework-based heterogenization approach that significantly enhances the photoredox activity perylene diimide species in radical addition reactions alkyl silicates by promoting faster and more efficient electron complex formation. Besides offering broad substrate scope alkene hydroalkylation, newly developed heterogeneous photocatalysis substantially improves turnover numbers comparison previous homogeneous photocatalytic systems demonstrates outstanding recyclability. These research findings pave way for advancement various practical transformations using framework-supported organocatalysts.

Язык: Английский

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Triply Selective & Sequential Diversification at C_sp³: Expansion of Alkyl Germane Reactivity for C−C & C−Heteroatom Bond Formation

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(16)

Опубликована: Фев. 22, 2024

Abstract We report the triply selective and sequential diversification of a single C sp 3 carbon carrying Cl, Bpin GeEt for modular programmable construction ‐rich molecules. Various functionalizations −Cl −BPin (e.g. alkylation, arylation, homologation, amination, hydroxylation) were tolerated by −GeEt group. Moreover, methodological repertoire alkyl germane functionalization was significantly expanded beyond hitherto known Giese addition arylation to alkynylation, alkenylation, cyanation, halogenation, azidation, C−S bond formation as well first demonstration stereo‐selective ‐[Ge] bond.

Язык: Английский

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Arylthianthrenium Salts for Triplet Energy Transfer Catalysis

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(44), С. 30474 - 30482

Опубликована: Окт. 28, 2024

Sigma bond cleavage through electronically excited states allows synthetically useful transformations with two radical species. Direct excitation of simple aryl halides to form both and halogen radicals necessitates UV-C light, so undesired side reactions are often observed specific equipment is required. Moreover, only extended π systems comparatively low triplet energy applicable transfer catalysis. Here we show the conceptual advantages arylthianthrenium salts (ArTTs) for catalysis high efficiency compared conventional (pseudo)halides their utility in arylation ethylene. The fundamental advance enabled by ArTTs that may originate large part from electronic interplay between distinct sulfur atoms tricyclic thianthrene scaffold, which not accessible either or other sulfonium salts.

Язык: Английский

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A Chemoselective Polarity‐Mismatched Photocatalytic C(sp³)−C(sp²) Cross‐Coupling Enabled by Synergistic Boron Activation**

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(42)

Опубликована: Авг. 25, 2023

We report the development of a C(sp

Язык: Английский

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Intramolecular and intermolecular benzannulation of arylethanone derivatives enabled by visible light-induced catalytic generation of tether-tunable distonic radical anions

Organic Chemistry Frontiers, Год журнала: 2025, Номер unknown

Опубликована: Янв. 1, 2025

A novel method enables inter-/intramolecular benzannulation to synthesize PAHs have been disclosed. Experimental and DFT data confirm the TDRA's role in HAA step of enolized 1,3-dicarbonyls via asynchronous PCET.

Язык: Английский

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