Asymmetric Dearomatization of Indoles through Cobalt‐Catalyzed Enantioselective C−H Functionalization Enabled by Photocatalysis

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

Опубликована: Июнь 20, 2024

Photocatalysis holds a pivotal position in modern organic synthesis, capable of inducing novel reactivities under mild and environmentally friendly reaction conditions. However, the merger photocatalysis transition-metal-catalyzed asymmetric C-H activation as an efficient sustainable method for construction chiral molecules remains elusive challenging. Herein, we develop cobalt-catalyzed enantioselective enabled by visible-light photoredox catalysis, providing synergistic catalytic strategy dearomatization indoles with high levels enantioselectivity (96 % to >99 ee). Mechanistic studies indicate that excited photocatalyst was quenched divalent cobalt species presence Salox ligand, leading formation catalytically active Co(III) complex. Moreover, stoichiometric reactions cobaltacycle intermediate indole suggest irradiation visible light also play critical role step.

Язык: Английский

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Enantioselective Dearomative [2π + 2σ] Photocycloaddition of Naphthalene Derivatives with Bicyclo[1.1.0]butanes Enabled by Gd(III) Catalysis

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

Опубликована: Март 28, 2025

The cycloaddition reactions of bicyclo[1.1.0]butanes with alkenes, imines, nitrones, or aziridines have served as an efficient platform to create conformationally restricted saturated bicyclic scaffolds. However, the use readily available aromatics in such reactions, especially asymmetric manner, remains underexplored. Herein, we report a highly regio- and enantioselective dearomative [2π + 2σ] photocycloaddition reaction between naphthalene derivatives bicyclo[1.1.0]butanes, enabled by Gd(III) catalysis. Bicyclo[1.1.0]butanes naphthalenes adorned diverse array functional groups are well-tolerated under mild conditions, affording enantioenriched pharmaceutically important bicyclo[2.1.1]hexanes 30–96% yields 81–93% ee 12:1 → >20:1 rr. synthetic versatility this is further demonstrated facile removal directing group derivatizations dearomatized product. UV–vis absorption spectroscopy studies suggest involvement excited species process.

Язык: Английский

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Reactivity of 3-nitroindoles with electron-rich species

Chemical Communications, Год журнала: 2020, Номер 57(1), С. 27 - 44

Опубликована: Ноя. 25, 2020

3-Nitroindoles behave as electron-poor aromatic compounds and react toward a number electron-rich species. This feature article presents an overview of this reactivity, mainly in (formal) dearomatizing cycloaddition reactions.

Язык: Английский

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Nickel-Catalyzed Dearomative Arylboration of Indoles: Regioselective Synthesis of C2- and C3-Borylated Indolines

Journal of the American Chemical Society, Год журнала: 2021, Номер 143(40), С. 16502 - 16511

Опубликована: Сен. 28, 2021

Indole dearomatization is an important strategy to access indolines: a motif present in variety of natural products and biologically active molecules. Herein, method for transition-metal catalyzed regioselective dearomative arylboration indoles generate diverse indolines presented. The accomplishes intermolecular simple through migratory insertion pathway on substrates that lack activating or directing groups the C2- C3-positions. Synthetically useful C3-borylated can be accessed change N-protecting group high regio- diastereoselectivities (up >40:1 rr dr) from readily available starting materials. Additionally, origin regioselectivity was explored experimentally computationally uncover remarkable interplay between carbonyl orientation indole, electronics C2–C3 π-bond, sterics. enabled first enantioselective synthesis (−)-azamedicarpin.

Язык: Английский

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Design, synthesis, and anticancer activity of novel 4-thiazolidinone-phenylaminopyrimidine hybrids

Molecular Diversity, Год журнала: 2020, Номер 25(2), С. 1025 - 1050

Опубликована: Апрель 23, 2020

Язык: Английский

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Catalytic Asymmetric Dearomative 1,3-Dipolar Cycloaddition of 2-Nitrobenzothiophenes and Isatin-Derived Azomethine Ylides

Organic Letters, Год журнала: 2021, Номер 23(21), С. 8600 - 8605

Опубликована: Окт. 21, 2021

An enantioselective dearomative 1,3-dipolar cycloaddition of 2-nitrobenzothiophenes and isatin-derived azomethine ylides with a bifunctional hydrogen-bonding thiourea catalyst was established, giving polyheterocyclic compounds in excellent results (up to 99% yield, >20:1 dr for all cases up ee). The enantioselectivity could be reversed by the squaramide containing same chiral source as catalyst. DFT calculations revealed origin observed stereochemistry reversal enantioselectivity.

Язык: Английский

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Ag-Catalyzed Asymmetric Interrupted Barton–Zard Reaction Enabling the Enantioselective Dearomatization of 2- and 3-Nitroindoles

Organic Letters, Год журнала: 2022, Номер 24(3), С. 826 - 831

Опубликована: Янв. 14, 2022

We disclose a Ag-catalyzed asymmetric interrupted Barton–Zard reaction of α-aryl-substituted isocyanoacetates with 2- and 3-nitroindoles, which enables the dearomatization nitroindoles hence offers rapid access to an array optically active tetrahydropyrrolo[3,4-b]indole derivatives bearing three contiguous stereogenic centers, including two tetrasubstituted chiral carbon atoms pretty outcomes (up 99% yield, 91:9 dr, 96% ee). The synthetic potential protocol was showcased by gram-scale versatile transformations product.

Язык: Английский

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Enantioselective Dearomatization of Indoles via SmI₂-Mediated Intermolecular Reductive Coupling with Ketones

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(18), С. 10314 - 10321

Опубликована: Апрель 26, 2023

Samarium diiodide (SmI2) mediated reductive coupling reactions are powerful methods for the construction of carbon-carbon bond in organic synthesis. Despite extensive development recent decades, successful examples corresponding asymmetric remained scarce, probably due to involvement highly reactive radical intermediates. In this Article, we report an enantioselective dearomatization indoles via SmI2-mediated intermolecular with ketones. The utilization samarium reductant supported by chiral tridentate aminodiol ligands allows facile synthesis indoline molecules bearing two contiguous stereogenic centers high yields (up 99%) and stereoselectivity 99:1 er >20:1 dr). Combined experimental computational investigations suggested that parallel single-electron transfer each substrate from radical-radical recombination manner, which is a unique mechanistic scenario reactions.

Язык: Английский

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(Indol-3-yl)(DMIX)Iodonium Salts: Novel Electrophilic Indole Reagents

Organic Letters, Год журнала: 2024, Номер 26(15), С. 3189 - 3194

Опубликована: Апрель 8, 2024

A new umpolung approach to the C3–H functionalization of indoles with diverse nucleophiles based on intermediate formation I(III) reagents is described. The 3,5-dimethylisoxazol-4-yl auxiliary allows for selective indole transfer under catalyst-free conditions, which was impossible using previously reported reagents. Combining mildness transition-metal-free conditions and high reactivity hypervalent iodine reagents, this protocol tolerates various functional groups provides access that are difficult prepare conventionally.

Язык: Английский

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Palladium-Catalyzed Asymmetric Decarboxylation of 5-Vinyloxazolidine-2,4-Diones Triggering the Dearomatization of Electron-Deficient Indoles for the Synthesis of Chiral Highly Functionalized Pyrroloindolines

Organic Letters, Год журнала: 2024, Номер 26(15), С. 3310 - 3315

Опубликована: Апрель 8, 2024

A catalyst system consisting of a chiral phosphoramidite ligand and Pd2(dba)3·CHCl3 causes the decarboxylation 5-vinyloxazolidine-2,4-diones to generate amide-containing aza-π-allylpalladium 1,3-dipole intermediates, which are capable triggering dearomatization 3-nitroindoles for diastereo- enantioselective [3+2] cycloaddition, leading formation series highly functionalized pyrroloindolines containing three contiguous stereogenic centers with excellent results (up 99% yield, 88:12 dr, 96% ee).

Язык: Английский

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