Photoinduced C(sp³)−H Bicyclopentylation Enabled by an Electron Donor–Acceptor Complex‐Mediated Chemoselective Three‐Component Radical Relay

Angewandte Chemie International Edition, Год журнала: 2024, Номер unknown

Опубликована: Апрель 10, 2024

The photoredox electron donor-acceptor (EDA) complex-mediated radical coupling reaction has gained prominence in the field of organic synthesis, finding widespread application two-component reactions. However, EDA complex-promoted multi-component reactions are not well developed with only a limited number examples have been reported. Herein, we report photoinduced and highly chemoselective three-component arylalkylation [1.1.1]propellane, which allows direct functionalization C(sp

Язык: Английский

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Sulfonamides as N-Centered Radical Precursors for C–N Coupling Reactions To Generate Amidines

Organic Letters, Год журнала: 2024, Номер 26(18), С. 3855 - 3860

Опубликована: Апрель 30, 2024

Nitrogen-centered radicals (NCRs) are valuable intermediates for the construction of C-N bonds. Traditional methods generation NCRs employ toxic radical initiators, transition metal catalysts, photocatalysts, or organometallic reagents. Herein, we report a novel strategy toward bonds under transition-metal-free conditions. Thus, super-electron-donor (SED) 2-azaallyl anions undergo single-electron transfer (SET) with sulfonamides, forming aminyl (R

Язык: Английский

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Efficient construction of functionalized pyrroloindolines through cascade radical cyclization/intermolecular coupling

Chemical Science, Год журнала: 2024, Номер 15(6), С. 2205 - 2210

Опубликована: Янв. 1, 2024

A novel tandem radical cyclization/intermolecular coupling between 2-azaallyl anions and indole N -aryloxy acetamides is developed, which enables the synthesis of C3a-substituted pyrroloindolines under mild conditions.

Язык: Английский

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Photocatalytic C(sp³)‐H gem‐Difluoroallylation and Alkylation with Alkenes via a Base‐Assisted Formal 1,2‐Hydrogen Atom Transfer of Amidyl Radicals

Chinese Journal of Chemistry, Год журнала: 2024, Номер 42(18), С. 2203 - 2210

Опубликована: Май 14, 2024

Comprehensive Summary Compared to well‐established 1,5‐HAT of N ‐centered radicals, the synthetic applications 1,2‐HAT process were scarce due high barrier and constrained three‐membered transition state. Here, we have developed a novel C(sp 3 )‐H gem ‐difluoroallylation via base assisted formal amidyl radicals with reductive quenching cycle photocatalyst. This transformation enables efficient formation α‐aminoalkyl showcases good functional group tolerance. Our preliminary mechanistic experiments, along Density Functional Theory (DFT) calculations demonstrate feasibility especially when by base. Furthermore, our method also succeeds in Giese addition electron‐deficient alkenes as well styrene.

Язык: Английский

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Organic Photoredox-Catalyzed Site-Selective Alkylation of Glycine Derivatives and Peptides via Infrequent 1,2-Hydrogen Atom Transfer of Amidyl Radicals

Organic Letters, Год журнала: 2024, Номер 26(36), С. 7638 - 7643

Опубликована: Сен. 4, 2024

Herein, we disclose a visible-light-driven photoredox-catalyzed protocol for site-selective alkylation of glycine derivatives via 1,2-hydrogen atom transfer, which is distinguished by metal free and mild conditions, high chemoselectivity, good functional group compatibility. This provides unique approach synthesizing valuable α,β-diamino acid derivatives. Furthermore, the potential synthetic merit this transformation proven scale-up reaction late-stage functionalization peptides.

Язык: Английский

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Recent Advances in Radical Coupling Strategies Enabled by 2‐Azaallyl Anions as Super‐Electron‐Donors

Advanced Synthesis & Catalysis, Год журнала: 2024, Номер 366(7), С. 1450 - 1466

Опубликована: Фев. 14, 2024

Abstract Due to amine derivatives widely existing in numerous clinical medicines and bioactive compounds, their synthesis has received considerable attention over the past few decades. Traditional methods for of largely relied on reduction nitroarenes, amides, hydrazines, nitriles, azides. Recently, discovery 2‐azaallyl anions as super‐electron‐donors (SEDs) opened up new possibilities construction diverse carbon‐carbon carbon‐heteroatom bonds through radical coupling strategies. This breakthrough highlights potential generating radicals versatile intermediates organic synthesis. Then, hydrolysis product can easily separate corresponding derivatives. Thus, tremendous been paid C−H functionalization ketimines an alternative strategy Herein, we comprehensively summarize recent progress strategies enabled by SEDs. Their proposed mechanistic pathways, advantages, limitations are also discussed detail. 1. Introduction 2. C−C Bond Formation 2.1. Vinylation Ketimines 2.2. Arylation 2.3. Alkylation 2.3.1. Methylation 2.3.2. Other 3. C−X 3.1. C−P C−S Bonds 3.2. C−N C−O 4. Conclusions

Язык: Английский

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Photocatalytic Strecker-Type Reaction for the Synthesis of Primary α-Aminonitriles

Organic Letters, Год журнала: 2025, Номер unknown

Опубликована: Март 17, 2025

A practical photoinduced direct N–O cleavage of oxime ethers via a single electron transfer (SET) process was developed, enabling controlled generation N–H imines iminyl radical intermediates. By employing this strategy, an efficient Strecker-type reaction established to construct variety primary α-aminonitriles using TMSCN as cyanide source. This protocol showed exceptional tolerance various functional groups, delivering the corresponding products in good yields. Mechanistic investigations indicate involvement radicals and radical/polar crossover sequence.

Язык: Английский

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Benzylic C(sp³)–H/C(sp³)–H Coupling with 2-Azaallyl Anions through Single-Electron Transfer and 1,5-Hydrogen Atom Transfer

Organic Letters, Год журнала: 2025, Номер unknown

Опубликована: Март 19, 2025

Herein is reported a novel transition-metal-free intermolecular C(sp3)–H/C(sp3)–H coupling of N-tert-butyl arylamides with N-benzyl imines through single-electron transfer (SET) and 1,5-hydrogen atom (1,5-HAT) strategies. 2-Azaallyl anions as super-electron-donors (SEDs) undergo SET to generate 2-azaallyl radicals amidyl radicals. The radical undergoes 1,5-HAT process form C-centered radical, which subsequently coupled new C–C bonds. This method avoids the use transition metals photoredox catalysts good functional group tolerance yields (29 examples, 87% yield). Radical clock trapping experiments provide significant evidence for

Язык: Английский

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Photocatalytic Amine-Promoted Selective Hydrochlorination and sp³ C–O Acylation of Alkyne-Tethered Methyl Ethers with Aldehydes

Organic Letters, Год журнала: 2025, Номер unknown

Опубликована: Март 27, 2025

We present a photoredox and alkylamine-assisted approach for the selective hydrochlorination acylation of sp3 C–O bonds in alkynyl methyl ethers using aldehydes. This method leverages cascade radical processes─including chlorine addition, hydrogen atom transfer, situ imine spin-center shift─to enable alkynes spontaneous cleavage bonds. The transformation accommodates broad range internal alkyne-tethered aldehydes, providing an efficient streamlined pathway to chloro-alkenyl ketones. Utilizing only photocatalyst, chloride, propylamine under light irradiation, this strategy offers practical complementary alternative previous protocols.

Язык: Английский

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Coupling of Acyl Radical Precursors with 2-Azaallyl Anions for the Synthesis of α-Amino Ketones

Organic Letters, Год журнала: 2025, Номер unknown

Опубликована: Май 1, 2025

A novel transition-metal-free radical coupling of 2-azaallyl anions for the synthesis α-amino ketones has been developed. Easily accessible thioesters and undergo single electron transfer (SET) to generate acyl radicals, which participate in intermolecular with good functional group tolerance yields (31 examples, up 98% yield). telescoped gram-scale derivatization product illustrate potential synthetic utility this method. Radical trapping clock experiments support proposed pathway between generated radical.

Язык: Английский

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