Copper-Catalyzed Umpolung of N-2,2,2-Trifluoroethylisatin Ketimines for the Enantioselective 1,3-Dipolar Cycloaddition with Benzo[b]thiophene Sulfones

Organic Letters, Год журнала: 2022, Номер 24(25), С. 4603 - 4608

Опубликована: Июнь 15, 2022

A copper-catalyzed umpolung of N-2,2,2-trifluoroethylisatin ketimines for the enantioselective 1,3-dipolar cycloaddition with benzo[b]thiophene sulfones was developed. Using a catalyst system consisting an (S,Sp)-tBu-Phosferrox ligand, Cu(OTf)2, and Cs2CO3, range pentacyclic spirooxindoles containing pyrrolidine benzo[b]sulfolane subunits were obtained in high efficiency excellent regio-, diastereo-, enantioselectivites under mild conditions. The practicality versatility reaction also demonstrated.

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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Cu-Catalyzed Asymmetric 1,3-Dipolar Cycloaddition of N-2,2,2-Trifluoroethylisatin Ketimines Enables the Desymmetrization of N-Arylmaleimides: Access to Enantioenriched F₃C-Containing Octahydropyrrolo[3,4-c]pyrroles

Organic Letters, Год журнала: 2022, Номер 24(22), С. 4052 - 4057

Опубликована: Май 27, 2022

With a Cu(OTf)2/chiral ferrocenyl P,N-ligand complex as catalyst, the enantioselective desymmetrization of N-arylmaleimides was successfully realized by taking advantage asymmetric 1,3-dipolar cycloaddition reaction N-2,2,2-trifluoroethylisatin ketimines. A series structurally diverse F3C-containing octahydropyrrolo[3,4-c]pyrroles, bearing four contiguous carbon stereocenters and one stereogenic chiral C-N axial bond, were obtained with excellent results (≤99% yield, >20:1 dr, 99% ee).

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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Dearomatization of 3-Nitroindoles Enabled Using Palladium-Catalyzed Decarboxylative [4 + 2] Cycloaddition of 2-Alkylidenetrimethylene Carbonates

The Journal of Organic Chemistry, Год журнала: 2022, Номер 87(9), С. 6025 - 6037

Опубликована: Апрель 18, 2022

A dearomatization process of 3-nitroindoles enabled using palladium-catalyzed decarboxylative [4 + 2] cycloaddition either 2-alkylidenetrimethylene carbonates or 2-(hydroxymethyl)-3-arylallyl has been developed, affording a wide range indoline-fused tetrahydropyrans in good yields with excellent diastereoselectivities. This reaction features substrate scope and mild conditions represents the first example application π-allyl palladium 1,4-[O,C]-dipole species for dearomative electron-deficient heteroarenes.

Язык: Английский

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Stereoselective synthesis of CF₃-containing spirocyclic-oxindoles using N-2,2,2-trifluoroethylisatin ketimines: an update

RSC Advances, Год журнала: 2023, Номер 13(11), С. 7063 - 7075

Опубликована: Янв. 1, 2023

Recent updates on the synthesis of CF 3 -containing spirocyclic-oxindoles by employing N -2,2,2-trifluoroethylisatin ketimines are described in this review article.

Язык: Английский

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Palladium-catalyzed asymmetric (4 + 3) cycloaddition of N-2,2,2-trifluoroethylisatin ketimines: access to optically active spirooxindoles

Organic Chemistry Frontiers, Год журнала: 2023, Номер 10(11), С. 2648 - 2652

Опубликована: Янв. 1, 2023

Herein, we disclose the first Pd-catalyzed enantioselective (4 + 3) cycloaddition of N -2,2,2-trifluoroethylisatin ketimines with 2-methylidenetrimethylene carbonate.

Язык: Английский

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Dearomatization of Nitro(hetero)arenes through Annulation

European Journal of Organic Chemistry, Год журнала: 2022, Номер 2022(18)

Опубликована: Апрель 5, 2022

Abstract Dearomatization reactions employing simple aromatic compounds have showcased remarkable progress in the recent decade and emerged as one of most straightforward powerful tools for creation highly functionalized, three‐dimensional molecular frameworks commonly encountered medicinal chemistry life sciences. Among use, nitro(hetero)arenes, which feature a less pronounced character due to presence electron‐withdrawing nitro group, been extensively used different types dearomatization reactions. The dearomative annulation reaction serves versatile method construction complex polycyclic systems. This overview presents brief summary impressive advances nitro(hetero)arenes provides some inspirations future research.

Язык: Английский

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Organocatalyzed asymmetric dearomative 1,3‐dipolar cycloaddition of 2‐nitrobenzofurans and N‐2,2,2‐trifluoroethylisatin ketimines

Chirality, Год журнала: 2022, Номер 34(7), С. 1019 - 1034

Опубликована: Май 6, 2022

Abstract A readily available chiral cyclohexanediamine‐derived bifunctional tertiary amine‐squaramide catalyst is more effective for the asymmetric dearomative 1,3‐dipolar cycloaddition of 2‐nitrobenzofurans and N ‐2,2,2‐trifluoroethylisatin ketimines. range structurally diverse spiro‐fused polyheterocyclic compounds containing oxindole, pyrrolidine, hydrobenzofuran motifs were smoothly obtained in excellent results (up to 99% yield, >20:1 dr all cases up ee). This method features high efficiency, mild reaction conditions, exquisite induction, wide functional group tolerance, great potential scale‐up synthesis, attractive product diversification.

Язык: Английский

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Thiol-Triggered Tandem Dearomative Michael Addition/Intramolecular Henry Reaction of 2-Nitrobenzofurans: Access to Sulfur-Containing Polyheterocyclic Compounds

Organic Letters, Год журнала: 2024, Номер 26(13), С. 2623 - 2628

Опубликована: Март 24, 2024

An efficient dearomative cyclization of 2-nitrobenzofurans via a thiol-triggered tandem Michael addition/intramolecular Henry reaction has been developed. A range thiochromeno[3,2-b]benzofuran-11-ols and tetrahydrothieno[3,2-b]benzofuran-3-ols could be obtained in up to 99% yield >20:1 dr. The valuable thiochromone fused benzofurans prepared with the 2-mercaptobenzaldehyde reaction/rearomatization/oxidative dehydrogenation process one-pot two-step operation. mechanism for was tentatively proposed.

Язык: Английский

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