The crucial role of silver(i)-salts as additives in C–H activation reactions: overall analysis of their versatility and applicability

Chemical Society Reviews, Journal Year: 2023, Volume and Issue: 52(18), P. 6359 - 6378

Published: Jan. 1, 2023

This review discusses the important role of silver( i ) salts as additives in transition-metal catalyzed C–H activation, and depicts discussion about current shift towards Ag-free procedures, plausible sustainable alternatives.

Language: Английский

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Rhodium(III)-Catalyzed Oxidative C–H Alkylation of Aniline Derivatives with Allylic Alcohols To Produce β-Aryl Ketones

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(8), P. 4394 - 4401

Published: March 29, 2022

The Rh(III)-catalyzed C–H oxidative alkylation of aniline derivatives with readily available secondary allyl alcohols using a pyrimidine-directing group, leading to the production β-aryl ketones, is described. A wide variety functional groups are tolerated in reaction. In reaction an alcohol bearing methyl group at α-hydroxy carbon, such as but-3-en-2-ol (2a), metal oxidant not required. sharp contrast, no occurs when 2a replaced ethyl, propyl, pentyl, and phenyl groups. these cases, addition Ag2CO3 necessary for proceed successfully. Mechanistic experiments suggest that acts alkylating reagent well through β-hydroxy elimination regenerate active Rh(III) species. required species reactants other than 2a. Thus, catalyst regeneration step different depending on structure alcohol.

Language: Английский

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Rh(III)-Catalyzed C–H Annulation of N-Nitrosoanilines with Iodonium Ylides for the Synthesis of N-Alkyl Indoles

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(11), P. 7281 - 7289

Published: May 19, 2023

A novel protocol for synthesizing N-alkyl indoles from readily available N-nitrosoanilines and iodonium ylides through the rhodium(III)-catalyzed C-H bond activation/intramolecular cyclization reaction has been described. This strategy employs nitroso as a traceless directing group. The transformation features powerful reactivity, tolerates various functional groups, proceeds with moderate yields under mild conditions, providing straightforward approach to access structurally diverse valuable indole derivatives.

Language: Английский

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Reverse Regioselective Cp*Co(III)-Catalyzed [4 + 2] C–H Annulation of N-Chloroamides with Vinylsilanes: Synthesis of 4-Silylated Isoquinolones and Their Synthetic Utilities

Organic Letters, Journal Year: 2023, Volume and Issue: 25(43), P. 7878 - 7883

Published: Oct. 23, 2023

We have developed a Cp*Co(III)-catalyzed reverse regioselective [4 + 2] annulation of N-chlorobenzamides/acrylamides with vinylsilanes for the synthesis 4-silylated isoquinolones. The reaction was performed at ambient temperature under redox-neutral conditions. utilized N-Cl bond as an internal oxidant, furnished required products excellent regioselectivities, and demonstrated high functional group tolerance. synthetic utility isoquinolones has been preparation 4-heteroarylated 4-alkylated via metal-free C-C couplings. Additionally, 3,4-dihydroisoquinolones were synthesized protodesilylation isoquinolones, thus making vinylsilane ethylene surrogate.

Language: Английский

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Electron-Deficient CpRh(III)-Catalyzed C–H Functionalization of N-2-Pyridylanilines: Branch-Selective Alkenylation with Alkenes and Annulation with Alkynes

The Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: March 20, 2025

We report the electron-deficient CpRh(III) [CpERh(III)] complex-catalyzed branch selective alkenylation with aliphatic alkenes and annulation internal alkynes using N-2-pyridylanilines. In these reactions, CpERh(III) catalyst is more active than electron-rich Cp*Rh(III) catalyst, used commonly in C–H activation, reactions proceed a catalytic amount of Cu(II) oxidant under air at lower temperatures conventional methods. From mechanistic considerations, steric repulsion between ligand directing group may be responsible for alkenylation.

Language: Английский

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Rhodium‐Catalyzed C–H Bond Annulation for the Synthesis of 5‐ and 6‐Membered N‐Heterocyclic Building Blocks

ChemCatChem, Journal Year: 2024, Volume and Issue: unknown

Published: May 17, 2024

Abstract The sustainable preparation of N ‐heterocycles is one the most active research areas owing to their predominance as synthetics building blocks with extensive applications in organic, pharmaceutical, and material chemistry fields. Among various catalytic protocols, C−H bond functionalization concomitant C−N formation, so‐called annulation, has become routes access because it starts from low‐functionalized materials generates a limited amount waste, all respecting concept atom economy. Rhodium complexes often catalyze these reactions. This review focuses on synthesis 5‐ 6‐membered ring ‐containing heterocycles such indoles, pyrroles, indolines, (iso)quinolinones, dihydroquinolines, pyrrolidones readily available starting materials, an emphasis novel cascade synthetic methodologies via C−N/C−C well mechanisms reactions, especially oxidation steps. We hope this will help researchers looking prepare minimum steps those who want develop new based activation/functionalizations.

Language: Английский

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Rhodium-Catalyzed Synthesis of 2-Methylindoles via C–N Bond Cleavage of N-Allylbenzimidazole

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(13), P. 7988 - 7997

Published: May 24, 2023

A rhodium-catalyzed oxidative C-H/N-H dehydrogenative [3 + 2] annulation strategy has been reported between anilines and N-allylbenzimidazole for the synthesis of 2-methylindole scaffolds. An used as a 2C synthon indole, more importantly, this transformation involves cleavage thermodynamically stable C-N bond allylamine. Detailed mechanistic studies have performed key intermediate was detected in HRMS. This proceeds through cascade C(sp2)-H allylation followed by intramolecular cyclization.

Language: Английский

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Ruthenium, rhodium and iridium complexes of a silyl-substituted N-heterocyclic carbene ligand and their catalytic performance in hydrosilylation of terminal alkynes

Journal of Organometallic Chemistry, Journal Year: 2023, Volume and Issue: 997, P. 122791 - 122791

Published: June 23, 2023

Language: Английский

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Rhodium-catalyzed synthesis of N-substituted 3-acylpyrroles from enaminones and vinylene carbonate

Organic Chemistry Frontiers, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 12, 2024

We developed a cascade C–H activation/[3 + 2] annulation for enaminones and vinylene carbonate, employing the catalyst [Cp*RhCl 2 ] oxidants. This reaction allows efficient synthesis of 3-carbonylpyrroles.

Language: Английский

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Synthesis of Indolines via Palladium-Catalyzed [4+1] Annulation of (2-Aminophenyl) Methanols with Sulfoxonium Ylides

Organic & Biomolecular Chemistry, Journal Year: 2024, Volume and Issue: 22(31), P. 6342 - 6351

Published: Jan. 1, 2024

A facile strategy for the synthesis of valuable indolines has been developed, involving a palladium(II)/Brønsted acid co-catalyzed annulation readily available (2-aminophenyl)methanols and sulfoxonium ylides. This protocol allows direct utilization OH group as leaving group, tolerates alkyl aryl groups on N atom aniline moiety, operates under mild reaction conditions, exhibits good efficiency.

Language: Английский

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