Rh(III)-Catalyzed Chemodivergent Annulations between Indoles and Iodonium Carbenes: A Rapid Access to Tricyclic and Tetracyclic N-Heterocylces

Organic Letters, Journal Year: 2021, Volume and Issue: 23(11), P. 4233 - 4238

Published: May 21, 2021

Herein, we report an acid-controlled highly tunable selectivity of Rh(III)-catalyzed [4 + 2] and [3 3] annulations N-carboxamide indoles with iodonium ylides lead to form synthetically important tricyclic tetracyclic N-heterocycles. Here, ylide serves as a carbene precursor. The protocol proceeds under operationally simple conditions provides novel scaffolds such 3,4-dihydroindolo[1,2-c]quinazoline-1,6(2H,5H)-dione 1H-[1,3]oxazino[3,4-a]indol-1-one derivatives broad range functional group tolerance moderate excellent yields. Furthermore, the synthetic utility was extended for various chemical transformations easily scaled up large-scale level.

Language: Английский

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The solvent-controlled Rh(iii)-catalyzed switchable [4+2] annulation of 2-arylIndoles with iodonium ylides

Chemical Communications, Journal Year: 2022, Volume and Issue: 58(41), P. 6140 - 6143

Published: Jan. 1, 2022

Highly selective and switchable [4+2] annulations of 2-arylindoles with iodonium ylides were achieved by performing solvent-controlled Rh(III)-catalyzed C-H activations. When using DCM as a solvent, the functionalization selectively delivered indolo[2,1-a]isoquinoline derivatives. In contrast, same catalytic system polar HFIP solvent predominately provided benzo[a]carbazole moieties.

Language: Английский

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Cobalt(III)-Catalyzed Regioselective C6 Olefination of 2-Pyridones Using Alkynes: Olefination/Directing Group Migration and Olefination

Organic Letters, Journal Year: 2021, Volume and Issue: 23(12), P. 4624 - 4629

Published: June 9, 2021

Co(III)-catalyzed highly regio- and stereoselective direct C6 olefination of 2-pyridones with alkynes has been developed the assistance chelation. Upon variation reaction conditions, react well diaryl via a olefination/directing group migration pathway to give tetrasubstituted 6-vinyl-2-pyridones, but C6-H terminal works effectively afford only C6-olefinated 2-pyridones. A judicious choice solvent an additive is crucial for catalysis. The protocols feature 100% atom economy, excellent site selectivity, high stereoselectivity, ample substrate scope, good compatibility functional groups. Synthetic applications are demonstrated, experimental studies density theory calculations conducted gain mechanistic insight into two transformations.

Language: Английский

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Synthesis of Indenone Derivatives by Rh(III)-Catalyzed C–H Functionalization of Sulfoxonium Ylides with 1,3-Diynes

Organic Letters, Journal Year: 2022, Volume and Issue: 24(18), P. 3395 - 3400

Published: May 5, 2022

The transition-metal-catalyzed C-H functionalization of sulfoxonium ylides with alkynes formally participates in [4 + 2] annulations to deliver the naphthol scaffolds. In contrast, herein we disclose first Rh(III)-catalyzed activation, followed by redox-neutral [3 annulation 1,3-diynes, which delivers alkynated indenone derivatives. This protocol features a good functional group tolerance, broad substrate scope, moderate excellent yields, and mild reaction conditions. mechanism was supported through ESI-HRMS characterizing key intermediates catalytic cycle.

Language: Английский

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Rh(III)-Catalyzed Divergent Synthesis of Alkynylated Imidazo[1,5-a]indoles and α,α-Difluoromethylene Tetrasubstituted Alkenes

Organic Letters, Journal Year: 2021, Volume and Issue: 23(15), P. 5766 - 5771

Published: July 19, 2021

Herein, we report the divergent synthesis of alkynylated imidazo[1,5-a]indoles and α,α-difluoromethylene tetrasubstituted alkenes through Rh(III)-catalyzed [4 + 1] annulation/alkyne moiety migration C–H alkenylation/DG migration, respectively. This protocol features tunable product selectivity, excellent chemo-, regio-, stereoselectivity, broad substrate scope, moderate to high yields, good tolerance functional groups, mild redox-neutral conditions.

Language: Английский

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Chemo-, Regio-, and Stereoselective Assembly of Polysubstituted Furan-2(5H)-ones Enabled by Rh(III)-Catalyzed Domino C–H Alkenylation/Directing Group Migration/Lactonization: A Combined Experimental and Computational Study

ACS Catalysis, Journal Year: 2021, Volume and Issue: 11(22), P. 13921 - 13934

Published: Nov. 2, 2021

Exploring multistep cascade reactions triggered by C–H activation are recognized as appealing, yet challenging. Herein, we disclose a Rh(III)-catalyzed domino coupling of N-carbamoyl indoles and 4-hydroxy-2-alkynoates for the streamlined assembly highly functionalized furan-2(5H)-ones in which carbamoyl-directing group (DG) is given dual role an auxiliary migrating acylating reagent via cleavage stable C–N bonds at room temperature. More importantly, obtained furan-2(5H)-one skeleton could be further under air situ C5–H hydroxylation simply switching solvent or additive, providing fully substituted with installation alcohol-based C5 quaternary carbon center. Detailed experimental studies density functional theory calculations reveal that Rh(III)-mediated tandem activation/alkyne insertion/DG migration/lactonization accounts developed transformation to achieve high functionalities observed exclusive selectivity. The potential biological application class potent PPARγ ligands highlights synthetic utility methodology. This protocol endowed several salient features including efficient activation, excellent chemo-, regio-, stereoselectivity, bond-forming efficiency (e.g., two C–C C–O bonds), solvent- additive-controlled product selectivity, good functional-group compatibility, mild redox-neutral conditions.

Language: Английский

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Ru(II)-Catalyzed C–H Functionalization of 2-Arylbenzimidazoles with Iodonium Ylides: A Straightforward Access to Bridgehead Polycyclic N-Heterocycles

The Journal of Organic Chemistry, Journal Year: 2022, Volume and Issue: 87(21), P. 13757 - 13762

Published: Oct. 25, 2022

Herein, we disclose an efficient ruthenium-catalyzed C–H functionalization of 2-arylbenzimidazoles/2-arylimidazoles with iodonium ylides leading to substituted tetracyclic and pentacyclic bridgehead N-heterocycles, wherein ylide acts as a carbene precursor. For the first time, proceeds through Ru–carbenoid intermediate. Further, synthetic utility this protocol was successfully shown for gram-scale synthesis useful transformations.

Language: Английский

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Synthesis of Indole-Fused Oxepines via C–H Activation Initiated Diastereoselective [5 + 2] Annulation of Indoles with 1,6-Enynes

Organic Letters, Journal Year: 2021, Volume and Issue: 23(21), P. 8365 - 8369

Published: Oct. 15, 2021

A rhodium-catalyzed diastereoselective formal [5 + 2] annulation of indoles with cyclohexadienone-containing 1,6-enynes has been established via indole 2,3-difunctionalization. The reaction, probably proceeding through tandem C2–H alkenylation and intramolecular Friedel–Crafts alkylation relay, provides rapid construction indole-fused oxepines in good to excellent yields a broad substrate scope. This method also features concomitant cis-hydrobenzo[b] oxepine scaffolds, core unit found numerous natural products important biological activities.

Language: Английский

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[RhCp*Cl₂]₂-Catalyzed Indole Functionalization: Synthesis of Bioinspired Indole-Fused Polycycles

ACS Omega, Journal Year: 2023, Volume and Issue: 8(31), P. 27894 - 27919

Published: July 25, 2023

Polycyclic fused indoles are ubiquitous in natural products and pharmaceuticals due to their immense structural diversity biological inference, making them suitable for charting broader chemical space. Indole-based polycycles continue be fascinating as well challenging targets synthetic fabrication because of characteristic frameworks possessing biologically intriguing compounds both origin. As a result, an assortment new processes catalytic routes has been established provide unified access these skeletons very efficient selective manner. Transition-metal-catalyzed processes, particular from rhodium(III), widely used endeavors increase molecular complexity efficiently. In recent years, this resulted significant progress reaching scaffolds with enormous activity based on core indole skeletons. Additionally, Rh(III)-catalyzed direct C–H functionalization benzannulation protocols moieties were one the most alluring techniques generate indole-fused polycyclic molecules This review sheds light developments toward synthesizing by cascade annulation methods using Rh(III)-[RhCp*Cl2]2-catalyzed pathways, which align comprehensive sophisticated field functionalization. Here, we looked at few cascade-based designs catalyzed Rh(III) that produced elaborate inspired bioactivity. The also strongly emphasizes mechanistic insights 1–2, 2–3, 3–4-fused systems, focusing routes. With emphasis efficiency product diversity, chosen carbocycles heterocycles least three fused, bridged, or spiro cages reviewed. newly created synthesis concepts toolkits accessing diazepine, indol-ones, carbazoles, benzo-indoles, illustrative privileged techniques, included featured collection.

Language: Английский

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Rh(III)‐Catalyzed Cross‐Coupling/Annulation of Two Carbene Precursors: Construction of Dihydrobenzo[c]chromen‐6‐one Scaffolds and Application in the Total Synthesis of Cannabinol

Asian Journal of Organic Chemistry, Journal Year: 2021, Volume and Issue: 11(1)

Published: Nov. 5, 2021

Abstract A cross‐coupling/annulation reaction of sulfoxonium ylides with iodonium has been reported by Rh(III)‐catalyzed C−H functionalization pathway to provide a direct access valuable dihydrobenzo[ c ]chromen‐6‐one derivatives. In this catalytic system, ylide functionality acts as traceless directing group (DG), and carbene precursor resulting in highly selective reaction. The synthetic utility methodology is demonstrated diverse transformations, core structure Urolithin derivatives total synthesis cannabinol natural product.

Language: Английский

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