Desymmetrization–Addition Reaction of Cyclopropenes to Imines via Synergistic Photoredox and Cobalt Catalysis

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(28), С. 18892 - 18898

Опубликована: Июль 5, 2024

Herein, we designed a reaction for the desymmetrization-addition of cyclopropenes to imines by leveraging synergy between photoredox and asymmetric cobalt catalysis. This protocol facilitated synthesis series chiral functionalized cyclopropanes with high yield, enantioselectivity, diastereoselectivity (44 examples, up 93% yield >99% ee). A possible mechanism involving cyclopropene desymmetrization Co-H species imine addition Co-alkyl was proposed. study provides novel route important extends frontier metallaphotoredox

Язык: Английский

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Photoinduced Regiodivergent and Enantioselective Cross-Coupling of Glycine Derivatives with Hydrocarbon Feedstocks

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

Опубликована: Янв. 2, 2025

Regiodivergent asymmetric synthesis represents a transformative strategy for the efficient generation of structurally diverse chiral products from single set starting materials, significantly enriching their enantiomeric composition. However, design radical-mediated regiodivergent and enantioselective reactions that can accommodate wide range functional groups substrates has posed significant challenges. The obstacles primarily lie in switching regioselectivity achieving high enantiodiscrimination, especially when dealing with high-energy intermediates. To address these issues, we have developed new catalytic system integrates photoinduced hydrogen atom transfer (HAT) copper catalysis, involving fine-tuning ligands, additives, other reaction parameters. facilitates cross-couplings between N-aryl glycine ester/amide derivatives abundant hydrocarbon feedstocks through strong C(sp3)–H bond activation. This approach allows controlled stereoselective formation C(sp3)–C(sp3) C(sp3)–N bonds, yielding rich variety C- or N-alkylated esters amides commendable yields (up to 92% yield), exclusive regioselectivities (typically >20:1 rr), enantioselectivities 96% ee). Our methodology not only provides promising avenue incorporation alkyl functionalities onto specific sites biologically molecules but also offers practical while simultaneously induction within photochemical reactions.

Язык: Английский

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Recent advances in C(sp³)–N bond formation via metallaphoto-redox catalysis

Chemical Communications, Год журнала: 2024, Номер 60(50), С. 6340 - 6361

Опубликована: Янв. 1, 2024

In this review, the state-of-the-art advances in radical-involved C(sp 3 )–N bond formation via metallaphotoredox catalysis have been highlighted, which are organized according to different catalytic modes, reaction types, and substrate classes.

Язык: Английский

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Aldehyde–Olefin Couplings Via Sulfoxylate-Mediated Oxidative Generation of Ketyl Radical Anions

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

Опубликована: Сен. 20, 2024

Ketyl radicals are valuable reactive intermediates because they allow carbonyl chemistry to be extended beyond traditional electrophilic reactivity through simple single-electron reduction a nucleophilic radical. However, this pathway is challenging due the large negative potentials of carbonyls, thus requiring highly reducing conditions. Herein, we describe development an alternative strategy access ketyl from aldehydes, which avoids by instead proceeding via oxidation and desulfination α-hydroxy sulfinates. These redox-active aldehyde adducts generated

Язык: Английский

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Manganese Complexes with Consecutive Mn(IV) → Mn(III) Excitation for Versatile Photoredox Catalysis

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(35), С. 24515 - 24525

Опубликована: Июль 30, 2024

Manganese complexes stand out as promising candidates for photocatalyst design, attributed to their eco- and biocompatibility, versatile valence states, capability facilitating multiple electronic excitations. However, several intrinsic constraints, such inadequate visible light response short excited-state lifetimes, hinder effective photoinduced electron transfer impede photoredox activation of substrates. To overcome this obstacle, we have developed a class manganese featuring boron-incorporated

Язык: Английский

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A General Enantioselective α-Alkyl Amino Acid Derivatives Synthesis Enabled by Cobalt-Catalyzed Reductive Addition

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

Опубликована: Сен. 12, 2024

Enantioenriched unnatural amino acids represent a prevalent motif in organic chemistry, with profound applications biochemistry, medicinal and materials science. Herein, we report cobalt-catalyzed aza-Barbier reaction of dehydroglycines unactivated alkyl halides to afford α-amino esters high enantioselectivity. This catalytic reductive alkylative addition protocol circumvents the use moisture-, air-sensitive organometallic reagents, stoichiometric chiral auxiliaries, enabling conversion variety primary, secondary, even tertiary α-alkyl-amino under mild conditions, thus leading broad functional group tolerance. The expedient access biologically active motifs demonstrates practicality this by reducing number synthetic steps enhancing efficiency.

Язык: Английский

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p-Diarylboryl Halothiophenols as Multifunctional Catalysts via Photoactive Intramolecular Frustrated Lewis Pairs

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(29), С. 20425 - 20431

Опубликована: Июль 8, 2024

p-Diarylboryl halothiophenols are developed and unequivocally characterized. Their photophysical properties catalytic performance unveiled by experimental theoretical investigations. This novel class of triarylboranes behaves as a Brønsted acid to generate the corresponding borylthiophenolate that can absorb visible light undergo intramolecular charge transfer form radical pair consisting boron anion thiyl radical, which acts single-electron reductant while engaging in hydrogen atom regenerate parent borylthiophenol. The synthetic relevance this mode action is demonstrated establishment unique catalysis integrates three different yet tunable functions single cycle, thereby allowing borylthiophenols solely promote assembly sterically congested 1,2-diols 1,2-aminoalcohol derivatives via radical–radical cross-coupling.

Язык: Английский

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Harnessing the potential of acyl triazoles in bifunctional cobalt-catalyzed radical cross-coupling reactions

Nature Communications, Год журнала: 2024, Номер 15(1)

Опубликована: Авг. 13, 2024

Persistent radicals facilitate numerous selective radical coupling reactions. Here, we have identified acyl triazole as a new and versatile moiety for generating persistent intermediates through single-electron transfer processes. The efficient generation of these is facilitated by the formation substrate-coordinated cobalt complexes, which subsequently engage in cross-coupling Remarkably, triazole-coordinated complexes exhibit metal-hydride hydrogen atom (MHAT) capabilities with alkenes, enabling synthesis diverse ketone products without need external ligands. By leveraging effect, this catalytic approach also allows development other reactions two representative precursors. discovery triazoles effective substrates ligands catalysis, combined bifunctional nature system, opens up avenues design sustainable organic transformations. radical-mediated has emerged powerful tool forging C–C bonds. authors identify processes, context cobalt-catalysed carbon-carbon couplings under photoirradiation.

Язык: Английский

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Cobalt-Catalyzed Asymmetric Migratory Nozaki–Hiyama–Kishi Coupling

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

Опубликована: Сен. 16, 2024

Selective functionalization of ubiquitous C-H bonds based on 1,

Язык: Английский

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Catalytic Asymmetric Barbier Reaction of Ketones with Unactivated Alkyl Electrophiles

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

Опубликована: Окт. 3, 2024

The Barbier reaction is a reductive-type addition of an aldehyde or ketone with organic electrophile in the presence terminal metal reductant, providing straightforward and efficient method for carbon-carbon bond formation. This possesses advantage circumventing preparation moisture- air-sensitive organometallic reagents. However, catalytic ketones to construct tetrasubstituted stereogenic centers largely underdeveloped, despite its great potential accessing synthetically challenging chiral tertiary alcohol. Particularly, leveraging unactivated alkyl electrophiles as coupling components still rarely exploited. Herein, we disclose photoredox-assisted cobalt-catalyzed asymmetric alkylative Barbier-type address aforementioned challenges, thereby allowing construction highly congested carbon centers. fragments could be either readily accessible halides redox-active esters generated through decarboxylative pathway. Both types include primary, secondary, ones, thus affording diverse enantioenriched alcohols broad substrate scope. enantioselective protocol applied expedient synthesis core structure

Язык: Английский

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