Synthesis of S(IV)‐Stereogenic Chiral Thio‐Oxazolidinones via Palladium‐Catalyzed Asymmetric [3+2] Annulations

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(13)

Опубликована: Янв. 29, 2024

Organic molecules bearing chiral sulfur stereocenters exert a great impact on asymmetric catalysis and synthesis, drugs, materials. Compared with acyclic ones, the catalytic synthesis of thio-heterocycles has largely lagged behind due to lack efficient synthetic strategies. Here we establish first modular platform access thio-oxazolidinones via Pd-catalyzed [3+2] annulations vinylethylene carbonates sulfinylanilines. This protocol is featured by readily available starting materials, high enantio- diastereoselectivity. In particular, an unusual effect non-chiral supporting ligand diastereoselectivity was observed. Possible reaction mechanisms stereocontrol models were proposed.

Язык: Английский

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Asymmetric Cascade Cyclization of Enynamides with Photogenerated Ketenes via Relay Gold and N-Oxide Catalysis

ACS Catalysis, Год журнала: 2024, Номер 14(3), С. 1741 - 1749

Опубликована: Янв. 18, 2024

An asymmetric cascade cyclization of enynamides and α-diazoketones to produce chiral bicyclic lactams bearing all-carbon quaternary stereocenters is realized with up 95% yield, 98% ee, >19:1 dr. The combination visible light photoactivation the relay gold N-oxide catalysis in a process enabled facile generation controlled assembly two reactive intermediates, ketene aza-o-quinone methide. Theoretical calculations revealed stepwise [4 + 2] cycloaddition mechanism, stereochemistry by amide group catalyst. Remarkably, this study presents first example N-oxides serving as catalysts for illustrates how strategy could be promising means access significant heterocyclic scaffolds.

Язык: Английский

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Asymmetric Trapping of Siloxyketenes In Situ Generated from [1,3]-Silyl Migration of α-Ketoacylsilanes: A Visible-Light-Driven Palladium-Catalyzed [4 + 2] Cycloaddition

ACS Catalysis, Год журнала: 2025, Номер unknown, С. 5796 - 5805

Опубликована: Март 25, 2025

The transition metal-catalyzed asymmetric [n + 2] cycloaddition reaction with oxy-substituted ketene intermediates remains a synthetic challenge due to the limited availability of suitable precursors. Herein, we report visible-light-driven, palladium-catalyzed [4 vinyl benzoxazinanones siloxyketene intermediates, generating structurally diverse chiral quinolinone derivatives satisfactory diastereo- and enantioselectivities. transient generation siloxyketenes from α-ketoacylsilylanes through visible-light-induced Brook rearrangement is important for success present cycloaddition. 13C-labeling experiments reveal pathway involving [1,3]-silyl migration process. side arm effects BOX ligand silyl steric hindrance α-ketoacylsilanes play crucial roles in stereoselectivity control, theoretical calculations provide insights into stereochemical outcome reaction.

Язык: Английский

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Copper-Catalyzed Asymmetric Nucleophilic Opening of 1,1,2,2-Tetrasubstituted Donor–Acceptor Cyclopropanes for the Synthesis of α-Tertiary Amines

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

Опубликована: Дек. 26, 2024

Catalytic asymmetric transformation of donor–acceptor cyclopropanes (DACs) has been proven to be a highly valuable and robust strategy construct diverse types enantioenriched molecules. However, the use 1,1,2,2-tetrasubstituted DACs form products bearing quaternary stereocenters remains long-term unsolved challenge. Here, we report copper-catalyzed aminative ring opening tetrasubstituted alkynyl that delivers myriad α-tertiary amines with high levels enantioselectivities. The alkyne, amine, ester moieties within enable further applications, including synthesis bioactive Mechanistic studies indicate zwitterionic intermediate copper-acetylide unit plays key role in process, which represents new mode for achieving catalytic DACs.

Язык: Английский

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Palladium-catalyzed enantioselective rearrangement of dienyl cyclopropanes

Chemical Science, Год журнала: 2023, Номер 14(12), С. 3346 - 3351

Опубликована: Янв. 1, 2023

Vinyl cyclopropanes (VCPs) are among the most useful three-carbon building blocks in organic synthesis. They commonly used as dienophiles a range of cycloaddition reactions. However, VCP rearrangement has not received much attention since its discovery 1959. In particular, enantioselective is synthetically challenging. Herein, we report first palladium-catalyzed regio- and VCPs (dienyl or trienyl cyclopropanes) for construction functionalized cyclopentene units high yields with excellent enantioselectivities 100% atom economy. The utility current protocol was highlighted by gram-scale experiment. Moreover, methodology provides platform accessing molecules containing cyclopentanes cyclopentenes.

Язык: Английский

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Lighting the way to diverse cyclic architectures: expanding the horizons with photogenerated ketenes in sustainable chemistry

Organic Chemistry Frontiers, Год журнала: 2023, Номер 10(18), С. 4474 - 4487

Опубликована: Янв. 1, 2023

Photogenerated ketenes simplify and accelerate the synthesis of diverse cyclic architectures demonstrate their promising applications in flow chemistry.

Язык: Английский

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Asymmetric Amination of Unstrained C(sp³)–C(sp³) Bonds

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(43), С. 29857 - 29864

Опубликована: Окт. 16, 2024

The asymmetric functionalization of unstrained C(sp3)–C(sp3) bonds could be a powerful strategy to stereoselectively reconstruct the backbone an organic compound, but such reactions are rare. Although allylic substitutions have been used frequently construct C–C by cleavage more reactive C–X (X is usually O atom ester) transition metals, reverse process that involves replacement bond with C–heteroatom rare and generally considered thermodynamically unfavorable. We show unstrained, inert σ can converted C–N via designed solubility-control strategy, which makes unfavorable possible. amination occurs range amine nucleophiles cleaves multiple classes alkyl in good yields high enantioselectivity. A novel resolution also reported transforms racemic amines corresponding optically active sequential conversion back bond. Mechanistic studies formation rate-limiting step driven low solubility salt formed from cleaved group nonpolar solvent.

Язык: Английский

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Modular Synthesis of Planar-Chiral Cyclononenes via trans-Retentive Trapping of π-Allyl-Pd Dipoles

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

Опубликована: Янв. 17, 2025

Trans-cycloalkenes are abundant in bioactive natural products and have been used as powerful tools chemical biology drug discovery. However, strategies for the modular synthesis of trans-cycloalkenes, especially planar-chiral medium-sized ones, with high efficiency selectivity, still remain elusive. Herein, we report a Pd-catalyzed asymmetric [7 + 2] cyclization strategy to address this challenge. As result, two types trans-cyclononenes bearing all-carbon chiral quaternary stereocenters produced up 85% yield, >99% ee, >19:1 dr (42 examples). The key success is maintenance trans-2H configuration π-allyl-Pd species along unusual linear selectivity during H-bond-assisted process. In addition, conversion planar chirality central its application selective bioimaging cancer cells via bioorthogonal reaction were performed demonstrate synthetic value methodology.

Язык: Английский

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Palladium-Catalyzed (3 + 2) Annulation of Azaborines with Vinyl Epoxides for Constructing Polycyclic Oxazaborolidines

The Journal of Organic Chemistry, Год журнала: 2025, Номер unknown

Опубликована: Март 25, 2025

A palladium-catalyzed (3 + 2) annulation of azaborines with vinyl epoxides has been established. By this strategy, various polycyclic oxazaborolidines structural diversity were synthesized in generally high yields (up to 99%). The can be scaled up and the further functionalized through olefin metathesis Heck reaction, which demonstrated good feasibility for downstream transformations. Moreover, catalytic asymmetric version accomplished under catalysis palladium/chiral phosphoramidite ligand, producing chiral overall enantioselectivities 98:2 er). This work not only represents first 1,2-azaborines but also offers an efficient strategy constructing benzooxazaborolidine skeletons, particularly those enantioenriched fashion.

Язык: Английский

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Enantioselective macrocyclization via catalytic metallic dipole relay

Nature Catalysis, Год журнала: 2025, Номер unknown

Опубликована: Апрель 4, 2025

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