Catalytic asymmetric dearomative [4 + 2] annulation of 2-nitrobenzofurans and 5H-thiazol-4-ones: stereoselective construction of dihydrobenzofuran-bridged polycyclic skeletons

Organic Chemistry Frontiers, Год журнала: 2021, Номер 8(22), С. 6330 - 6336

Опубликована: Янв. 1, 2021

An organocatalytic asymmetric dearomative [4 + 2] annulation of 2-nitrobenzofurans and 5 H -thiazol-4-ones is developed for the construction dihydrobenzofuran-bridged polycyclic skeletons with good results.

Язык: Английский

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Copper(I)-catalyzed asymmetric 1,3-dipolar cycloaddition of 1,3-enynes and azomethine ylides

Nature Communications, Год журнала: 2023, Номер 14(1)

Опубликована: Авг. 4, 2023

Herein, we report a copper(I)-catalyzed asymmetric 1,3-dipolar cycloaddition of azomethine ylides and 1,3-enynes, which provides series chiral poly-substituted pyrrolidines in high regio-, diastereo-, enantioselectivities. Both 4-aryl-1,3-enynes 4-silyl-1,3-enynes serve as suitable dipolarophiles while 4-alkyl-1,3-enynes are inert. Moreover, the method is successfully applied construction both tetrasubstituted stereogenic carbon centers spiro pyrrolidines. The DFT calculations also conducted, imply concerted mechanism rather than stepwise mechanism. Finally, various transformations started from pyrrolidine bearing triethylsilylethynyl group centered on alkyne achieved, compensates for inertness present reaction.

Язык: Английский

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Asymmetric Domino Heck/Dearomatization Reaction of β-Naphthols to Construct Indole–Terpenoid Frameworks

Organic Letters, Год журнала: 2021, Номер 23(20), С. 7865 - 7872

Опубликована: Сен. 28, 2021

A palladium-catalyzed enantioselective Heck cyclization/dearomatization cascade via capturing the cyclized π-allylpalladium intermediate by β-naphthols is reported, which provides a new strategy for construction of chiral indole-terpenoid frameworks. This method affords indole-functionalized β-naphthalenone compounds bearing an all-carbon-substituted quaternary center in excellent yields (up to 92%) and enantioselectivities 94% ee). In addition, utility this showcased gram-scale syntheses diverse transformations dearomatized products.

Язык: Английский

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Bifunctinoal Phosphonium Salt‐Catalyzed Asymmetric Cyclodearomatization of 2‐Nitroindoles and 2‐Nitrobenzofurans for Constructing CF₃‐Containing Spiro‐Polycycles

Advanced Synthesis & Catalysis, Год журнала: 2021, Номер 363(12), С. 3115 - 3120

Опубликована: Апрель 13, 2021

Abstract An efficient enantioselective dearomative cycloaddition reaction between either 2‐nitroindoles or 2‐nitrobenzofurans and N ‐2,2,2‐trifluoroethylisatin ketimines by dipeptided phosphonium salt catalysis is firstly established. This protocol provides a new facile synthetic approach to create variety of CF 3 ‐containing polycyclic spirooxindole derivatives under mild conditions with high yields in excellent diastereo‐ enantioselectivities (all >20:1 dr , up 95% ee). magnified image

Язык: Английский

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Construction of Nitrogen-Containing Three-Dimensional Frameworks via Formation and Cycloaddition of endo-Cyclic Azomethine Ylide

Organic Letters, Год журнала: 2025, Номер unknown

Опубликована: Май 8, 2025

Triggered by the reaction of an oxime ether with a rhodium carbenoid, nitrogen-containing three-dimensional frameworks were constructed from linear motifs via intramolecular cycloaddition endo-cyclic azomethine ylide. In this transformation, successive stereocenters containing quaternary carbons formed, affording corresponding tricyclic compounds in moderate-to-good yields. The utility these products was demonstrated through several transformations.

Язык: Английский

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Catalytic Enantioselective Dearomatization/Rearomatization of 2-Nitroindoles to Access 3-Indolyl-3′-Aryl-/Alkyloxindoles: Application in the Formal Synthesis of Cyclotryptamine Alkaloids

Organic Letters, Год журнала: 2020, Номер 22(18), С. 7088 - 7093

Опубликована: Авг. 28, 2020

The first catalytic enantioselective dearomatization/rearomatization of 2-nitroindoles triggered by the Michael addition 3-monosubstituted oxindoles was established. A wide range 3-indolyl-3'-alkyloxindoles (up to 99% yield, 97% ee) and 3-indolyl-3'-aryloxindoles 95% were obtained using an organocatalyst. This method provides unprecedented strategy access structurally diverse 3,3'-disubstituted bearing a sterically congested triaryl-containing all-carbon quaternary stereocenter. utility this approach verified formal synthesis cyclotryptamine alkaloids.

Язык: Английский

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Dinuclear Zinc Catalyzed Enantioselective Dearomatization [3+2] Annulation of 2‐Nitrobenzofurans and 2‐Nitrobenzothiophenes

Chemistry - A European Journal, Год журнала: 2021, Номер 28(2)

Опубликована: Окт. 29, 2021

The application of dinuclear zinc catalysts in a dearomatization reaction has been developed. Catalytic asymmetric [3+2] annulations 2-nitrobenzofurans or 2-nitrobenzothiophenes with CF3 -containing N-unprotected isatin-derived azomethine ylides catalyzed by are realized excellent diastereomer ratios (dr) >20 : 1 and enantiomeric excess (ee) up to 99 %. This protocol provides practical, straightforward access structurally diverse pyrrolidinyl spirooxindoles containing 2,3-fused-dihydrobenzofuran (or dihydrobenzothiphene) moiety, four contiguous stereocenters. Reactions can be performed on gram scale. absolute configuration products is confirmed X-ray single crystal structure analysis, possible mechanism proposed.

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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Higher-order [10 + 2] cycloaddition of 2-alkylidene-1-indanones enables the dearomatization of 3-nitroindoles: access to polycyclic cyclopenta[b]indoline derivatives

Organic Chemistry Frontiers, Год журнала: 2022, Номер 9(12), С. 3322 - 3327

Опубликована: Янв. 1, 2022

The higher-order [10 + 2] cycloaddition of 3-nitroindoles and 2-alkylidene-1-indanones enables the dearomatization affords a range structurally diverse cyclopenta[ b ]indolines with excellent results.

Язык: Английский

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