Rh(III)-Catalyzed [3 + 2] Annulation/Pinacol Rearrangement Reaction of Enaminones with Iodonium Ylides: Direct Synthesis of 2-Spirocyclo-pyrrol-3-ones

Organic Letters, Год журнала: 2023, Номер 25(39), С. 7214 - 7219

Опубликована: Сен. 26, 2023

A novel Rh(III)-catalyzed cascade alkenyl C-H activation/[3 + 2] annulation/pinacol rearrangement reaction of enaminones with iodonium ylides has been developed. This methodology provides a new and straightforward synthetic strategy to afford highly functionalized 2-spirocyclo-pyrrol-3-ones in satisfactory yield from readily available starting materials under mild conditions. Moreover, gram-scale reactions further derivatization experiments are implemented demonstrate the potential utility this developed approach.

Язык: Английский

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Catalytic Asymmetric Cascade Dearomatization of Indoles via a Photoinduced Pd‐Catalyzed 1,2‐Bisfunctionalization of Butadienes

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(26)

Опубликована: Апрель 20, 2024

Photoinduced Pd-catalyzed bisfunctionalization of butadienes with a readily available organic halide and nucleophile represents an emerging attractive method to assemble versatile alkenes bearing various functional groups at the allylic position. However, enantiocontrol and/or diastereocontrol in C-C or C-X bond-formation step have not been solved due open-shell process. Herein, we present cascade asymmetric dearomatization reaction indoles via photoexcited 1,2-biscarbonfunctionalization 1,3-butadienes, wherein control on both electrophile part is achieved for first time photoinduced butadienes. This delivers structurally novel chiral spiroindolenines two contiguous stereogenic centers high diastereomeric ratios (up >20 : 1 dr) good excellent enantiomeric 97 3 er). Experimental computational studies mechanism confirmed radical pathway involving excited-state palladium catalysis. The alignment non-covalent interactions between substrate catalyst were found be essential stereocontrol.

Язык: Английский

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Enantioselective Copper-Catalyzed Dearomative Spiroannulation of β-Naphthols or Indoles with Yne-Allylic Esters

ACS Catalysis, Год журнала: 2024, Номер 14(12), С. 9254 - 9264

Опубликована: Июнь 3, 2024

Catalytic asymmetric dearomatization reactions of α-unsubstituted β-naphthols are very challenging due to the high energy barrier resulting from loss aromaticity. Herein, we describe an example enantioselective catalytic dearomative spiroannulation with yne-allylic esters. The success this reaction relied on copper-catalyzed remote strategy using esters as bis-electrophilic reagents. This transformation features mild conditions, broad functional group tolerance, and extensive substrate scope, thereby facilitating efficient construction array enantioenriched naphthalene-2-one spiroindolenine derivatives. Experimental studies density theory calculations establish pathway origin stereoselectivity.

Язык: Английский

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Diastereocontrolled Construction of Spiroindolenines via Hexafluoroisopropanol-Promoted Dearomative Epoxide–Indole Cyclization

Organic Letters, Год журнала: 2024, Номер 26(5), С. 1088 - 1093

Опубликована: Янв. 25, 2024

Herein, we report the discovery of ipso-selective, dearomatizing spirocyclization indole-tethered epoxides as a fundamentally new approach for constructing spiroindolenines equipped with three contiguous stereogenic centers under complete diastereocontrol (dr >99:1) and in high yields. Promoted by hexafluoroisopropanol, protocol features broad substrate scope, easy scale-up, versatile transformations synthesized spiroindolenines.

Язык: Английский

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Ynones in dearomative spirocyclisation processes; a review

Tetrahedron Chem, Год журнала: 2024, Номер 9, С. 100055 - 100055

Опубликована: Янв. 14, 2024

This review concentrates on our research into the discovery of novel ynone-based dearomative spirocyclisation processes, whilst placing new chemistry context existing knowledge. The genesis programme, development efficient synthetic routes to prepare natural products spirobacillene A (1) and B (2), utilised indole ynones. stimulated a much wider study explore reactivity ynones in processes more generally. Routes generate wide range spirocycles were subsequently developed, with reactions tethered indoles, benzofurans, benzisoxazoles, pyrroles, pyridines, isoquinolines, pyrazines, cyclic ketimines, anisoles all discussed herein, these initiated by catalytic Ag(I), Cu(II), Pd(0), photolysis many other reagents. Asymmetric variants some are also discussed, as is further elaboration spirocyclic give carbazoles, quinolones, polycycles useful building blocks. Finally, applications methodology product synthesis (e.g. A, lasubine II indolizidine 209D) described.

Язык: Английский

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Dearomative [4 + 2] cycloaddition of 3‐nitroindoles with ortho‐amino Morita−Baylis−Hillman carbonates to forge indole‐fused quinolines

Journal of Heterocyclic Chemistry, Год журнала: 2024, Номер 61(3), С. 528 - 537

Опубликована: Янв. 16, 2024

Abstract A dearomative [4 + 2] cycloaddition of 3‐nitroindoles ortho ‐amino Morita−Baylis−Hillman carbonates was established under mild conditions. This method provides an efficient and practical approach for delivering tetrahydro‐5 H ‐indolo[2,3‐ b ]quinolines containing three contiguous stereocenters, two tertiary one quaternary, in high yield (up to 95%) with excellent diastereoselectivity (all cases >25:1 dr ). The potential synthetic applications this strategy were also highlighted by the scale‐up experiment further transformation. Moreover, structure relative configuration cycloadduct unequivocally confirmed single‐crystal X‐ray diffraction.

Язык: Английский

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Indolyl‐Ynones: Building Blocks for Molecular Diversity

Advanced Synthesis & Catalysis, Год журнала: 2024, Номер 366(5), С. 1044 - 1058

Опубликована: Янв. 12, 2024

Abstract This review centers on the synthetic strategies employed with indolyl‐ynones. Indolyl‐ynone, owing to its highly reactive ynone moiety, frequently partakes in dearomatizing spirocyclization reactions and subsequent rearrangement when subjected various reaction conditions. Hence, heterocycles such as densely functionalized spiroindolenines, carbazoles, quinolines carbo‐and hetero‐cycle substituted indoles are synthesized from In addition this, versatile spirocyclic indole scaffold exhibits capability produce tetracyclic polyclic structures through intricate skeletal processes. Moreover, total synthesis of natural products using indolyl‐ynone moiety was also compiled this review.

Язык: Английский

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Catalyst-Free gem-Difluorination/Spirocyclization of Indole-2-carboxamides: Synthesis of C2-Spiroindoline Derivatives

Organic Letters, Год журнала: 2023, Номер 25(48), С. 8771 - 8776

Опубликована: Ноя. 28, 2023

A catalyst-free gem-difluorination/spirocyclization reaction has been successfully developed for the synthesis of gem-difluorinated C2-spiroindoline derivatives from indole-2-carboxamides. The resulting C2-spiroindolines can be easily converted into 2-spiropseudoindoxyls through hydrolysis. This method offers benefits simple operation, convenient access to raw materials, and mild conditions. Dual function Selectfluor in this is noteworthy as it serve both a fluorinating agent an alkaline accelerator precursor.

Язык: Английский

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Solvent-controlled switchable multicomponent tandem oxidative triple functionalization of indolines

Organic Chemistry Frontiers, Год журнала: 2024, Номер 11(7), С. 1933 - 1940

Опубликована: Янв. 1, 2024

A new one-pot method for solvent-controlled switchable tandem oxidative triple functionalization of indolines has been developed via successive regioselective chalcogenation, oxidation, amination and halogenation.

Язык: Английский

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Cobalt(II)-Catalyzed Selective C2–H Heck Reaction of Native (N–H) Indoles Enabled by Salicylaldehyde Ligand

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

Опубликована: Янв. 8, 2025

Direct functionalization of native (N–H) indoles via C–H activation remains a challenge. Herein, we report salicylaldehyde-promoted cobalt-catalyzed selective C2–H Heck reaction with both active and unactivated olefins in the presence free N–H bonds. A series structurally diverse C2-alkenylated including natural product drug derivatives were prepared directly effectively without additional preprotection deprotection procedures.

Язык: Английский

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