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

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(28), P. 18892 - 18898

Published: July 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

Language: Английский

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

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 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.

Language: Английский

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A General Copper‐Box System for the Asymmetric Arylative Functionalization of Benzylic, Propargylic or Allenylic Radicals

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: unknown

Published: July 27, 2024

Abstract Radical‐involved arylative cross‐coupling reactions have recently emerged as an attractive strategy to access valuable aryl‐substituted motifs. However, there still exist several challenges such limited scope of radical precursors/acceptors, and lack general asymmetric catalytic systems, especially regarding the multicomponent variants. Herein, we reported a copper‐Box system for three‐component vinylarenes 1,3‐enynes, with oxime carbonates aryl boronic acids. The proceed under practical conditions in absence or presence visible‐light irradiation, affording chiral 1,1‐diarylalkanes, benzylic alkynes allenes good enantioselectivities. Mechanistic studies imply that copper/Box complexes play dual role both generation ensuing cross‐coupling. In cases irradiation could improve activity complex toward initial generation, enabling better efficiency match between formation

Language: Английский

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Copper-Catalyzed sp² C–H Arylation and Alkynylation of Allenes via Hydrogen Atom Abstraction

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(35), P. 24689 - 24698

Published: Aug. 21, 2024

Development of methods for the sp2 C–H transformations allenes has received much attention, and it presents a powerful tool synthesis complicated allene-containing bioactive molecules. With copper-catalyzed radical relay, allenic arylation alkynylation were established herein, using various aryl boronic acids trimethoxysilyl-substituted alkynes as carbon nucleophiles electrophilic N–F reagents nitrogen-centered precursors. These featured excellent site selectivity to deliver fully substituted efficiently. Moreover, with silyl-substituted substrates, subsequent dual functionalization process was well, which allowed divergent multifunctionalized allenes, significantly expanding their chemical spaces.

Language: Английский

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Construction of planar chiral [2,2]paracyclophanes via photoinduced cobalt-catalyzed desymmetric addition

Nature Communications, Journal Year: 2025, Volume and Issue: 16(1)

Published: April 29, 2025

Language: Английский

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A General Copper-Box System for the Asymmetric Ary-lative Functionalization of Benzylic, Propargylic or Allenylic Radicals

Published: June 12, 2024

Radical-involved arylative cross-coupling reactions have recently emerged as an attractive strategy to access valuable aryl-substituted motifs. However, there still exist several challenges such limited scope of radi-cal precursors/acceptors, and lack general asymmetric catalytic systems, especially regarding the multicom-ponent variants. Herein, we reported a copper-Box system for three-component vinylarenes 1,3-enynes, with oxime carbonates aryl boronic acids. The proceed under practical conditions in absence or presence visible-light irradiation, affording chiral 1,1-diarylalkanes, benzylic alkynes allenes good enantioselectivities. Mechanistic studies imply that copper/Box complexes play dual role both radical generation ensuing cross-coupling. In cases irradiation could improve activity complex toward initial generation, enabling better efficiency match between formation

Language: Английский

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Unusual Regioselective C–H Difluoroalkylation of Heteroarenes under Photoredox Catalysis

Organic Letters, Journal Year: 2024, Volume and Issue: 26(24), P. 5098 - 5104

Published: June 7, 2024

We disclose a new general strategy for the site-selective difluoroalkylation of nonprefunctionalized heteroarenes, such as quinoxaline at C-8 position, and benzothiadiazole, benzoxadiazole, benzothiazole C-4 position via consecutive organophotoredox-catalyzed radical–radical cross-coupling base-assisted hydrogen abstraction reactions. The current methodology represents direct difluoroalkylative to allow broad functional group tolerance wide substrate scope in good excellent yields. Careful experimental investigations detailed DFT calculations revealed exact site-selectivity heteroarenes possible mechanistic pathway.

Language: Английский

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Hydrogen Bonding-Induced Aggregation of Chiral Functionalized AuNS@Ag NPs for Photothermal Enantioanalysis

Analytical Chemistry, Journal Year: 2024, Volume and Issue: 96(16), P. 6292 - 6300

Published: April 10, 2024

Toward the challenges of signaling transduction amplified in enantioselective recognition, we herein devised an innovative strategy for highly selective recognition amino acids and their derivatives, leveraging photothermal effects. In this approach, bifunctional l-ascorbic acid is employed to reduce silver ions

Language: Английский

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Enantioconvergent and Site‐Selective Etherification of Carbohydrate Polyols through Chiral Copper Radical Catalysis

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(48)

Published: Aug. 17, 2024

Abstract Going beyond currently reported two electron transformations that formed the core backdrop of asymmetric catalytic site‐selective carbohydrate polyol functionalizations, we herein report a seminal demonstration an enantioconvergent copper catalyzed etherification minimally protected saccharides through single‐electron radical pathway. Further, this strategy paves rare strategy, which carboxamide scaffold is present in some glycomimetics pharmacological relevance, can be selectively introduced. In light burgeoning interest chiral catalysis, and virtual absence such stereocontrol broadly synthesis, our showcased unknown capability catalysis as contemporary tool to address formidable site‐selectivity challenge on remarkable palette naturally occurring saccharides. When reducing sugars were employed, further dynamic kinetic resolution type glycosylation activated by system generate challenging β‐ O ‐glycosides.

Language: Английский

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Photoinduced copper-catalyzed alkoxycarbonylation of alkyl fluorides

Organic Chemistry Frontiers, Journal Year: 2024, Volume and Issue: 11(9), P. 2462 - 2467

Published: Jan. 1, 2024

A photoinduced copper-catalyzed alkoxycarbonylation of alkyl fluorides with phenols to synthesize various esters has been developed.

Language: Английский

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