Rh-Catalyzed [4 + 2] Annulation with a Removable Monodentate Structure toward Iminopyranes and Pyranones by C–H Annulation

Organic Letters, Journal Year: 2022, Volume and Issue: 24(16), P. 3003 - 3008

Published: April 20, 2022

The Rh-catalyzed reactions of N-pyridinyl enaminones with internal alkynes leading to the synthesis iminopyranes via a key C–H bond activation and subsequent tautomeric O–H cleavage are reported. Moreover, pyridine ring in amino group acts as an auxiliary monodentate site for this annulation can be easily removed by simple hydrolysis afford pyranones.

Language: Английский

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Three-component synthesis ofN-naphthyl pyrazolesviaRh(iii)-catalyzed cascade pyrazole annulation and Satoh–Miura benzannulation

Chemical Communications, Journal Year: 2023, Volume and Issue: 59(27), P. 4036 - 4039

Published: Jan. 1, 2023

The synthesis of N-naphthyl pyrazoles has been realized by the direct three-component reactions enaminones, aryl hydrazine hydrochlorides and internal alkynes via Rh(III) catalysis. synthetic employing simple substrates lead to simultaneous construction dual cyclic moieties, including a pyrazole ring phenyl ring, sequential formation two C-N three C-C bonds.

Language: Английский

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

Organic Letters, Journal Year: 2023, Volume and Issue: 25(39), P. 7214 - 7219

Published: Sept. 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.

Language: Английский

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Selective Synthesis of C4-Functionalized Benzofurans by Rhodium-Catalyzed Vinylene Transfer: Computational Study on the Cyclopentadienyl Ligand

Organic Letters, Journal Year: 2022, Volume and Issue: 24(31), P. 5679 - 5683

Published: July 28, 2022

Benzofuran is a privileged structure in many bioactive compounds; however, the controlled synthesis of C2,C3-nonsubstituted benzofurans has been scarce. In particular, cumbersome multistep processes are inevitable for most inaccessible C4-substituted isomers. Herein, we report Rh-catalyzed direct vinylene annulation readily available m-salicylic acid derivatives with carbonate to achieve selective construction benzofurans. The Weinreb amide directing group facilitated following product derivatization. reaction mechanism was investigated by DFT calculations.

Language: Английский

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Recent advances in rhodium-catalyzed C(sp²)–H (hetero)arylation

Organic & Biomolecular Chemistry, Journal Year: 2021, Volume and Issue: 19(39), P. 8442 - 8465

Published: Jan. 1, 2021

Recent achievements in rhodium-catalyzed arylations through C(sp 2 )–H bond activation were summarized.

Language: Английский

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Diverse reactivity of alkynes in C–H activation reactions

Chemical Communications, Journal Year: 2022, Volume and Issue: 58(74), P. 10262 - 10289

Published: Jan. 1, 2022

The metal–carbon bond generated through C–H activation is a key organometallic intermediate, which could be further functionalized with various reacting partners. Among the coupling partners used in metal-catalysed activation, alkynes occupy prominent position on account of their varied reactivity.

Language: Английский

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Rhodium-Catalyzed Isoquinoline Synthesis Using Vinyl Selenone as Oxidizing Acetylene Surrogate

Organic Letters, Journal Year: 2023, Volume and Issue: 25(18), P. 3206 - 3209

Published: May 4, 2023

Isoquinoline is a privileged structure in many bioactive compounds and valuable ligands. Transition-metal-catalyzed oxidative annulation of imine derivatives has become promising synthetic method; however, catalytic synthesis 3,4-nonsubstituted isoquinolines by formal acetylene been scarce to date. Herein, we introduce vinyl selenone as an effective surrogate for the Rh-catalyzed annulative coupling under mild conditions. The Se fragment can be recovered diselenide recycled. product readily converted 1-aminoisoquinolines.

Language: Английский

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Rhenium-catalyzed synthetic method of 1,2-dihydroisoquinolines and isoquinolines by the intramolecular cyclization of 2-alkynylaldimines or 2-alkynylbenzylamines

Tetrahedron, Journal Year: 2024, Volume and Issue: 154, P. 133854 - 133854

Published: Feb. 2, 2024

Language: Английский

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Breaking the Trend: Insight into Unforeseen Reactivity of Alkynes in Cobalt-Catalyzed Weak Chelation-Assisted Regioselective C(4)–H Functionalization of 3-Pivaloyl Indole

ACS Catalysis, Journal Year: 2021, Volume and Issue: 11(18), P. 11579 - 11587

Published: Sept. 3, 2021

Unique reactivity of diphenylacetylene has been uncovered through weak chelation-assisted cobalt-catalyzed regioselective C(4)–H activation 3-pivolyl indole. α-Hydroxy ketone and α,β-unsaturated derivatives have synthesized in good yields from indole alkynes. Notably, the C(4)–H-functionalized product was obtained with high stereo- regioselectivity simply by changing coupling partner symmetrical alkynes to unsymmetrical aromatic-aliphatic Most importantly, trifluoroethanol acts as a sole source water for this conversion. Quantitative detection bis(2,2,2-trifluoroethyl) ether dry 19F NMR LCMS studies indirectly confirms situ formation water. A six-membered cobaltacycle intermediate detected HRMS, also, further confirmed quantum mechanical calculations, which accounts highly functionalization.

Language: Английский

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Visible-Light-Induced Synthesis of 2-Sulfenylated Pyrrolo[1,2-α]quinoxalines via Isocyanides and Disulfides Cascade Radical Reactions

Organic & Biomolecular Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

We have developed a visible-light-driven photocatalytic tandem reaction system to achieve the efficient synthesis of 2-sulfenylated pyrrolo[1,2-α]quinoxalines based on radical addition-cyclization mechanism. Mechanistic studies show that sulfur intermediates generated in directly participate subsequent formation C-S bonds. This strategy has opened up an synthetic pathway for precise C2-sulfur-substituted heterocyclic compounds.

Language: Английский

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