Direct Alkylation of Glycine Derivatives via Photoinduced Palladium Catalysis, Utilizing Intermolecular Hydrogen Atom Transfer Mediated by Alkyl Radicals

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(24), P. 15652 - 15662

Published: Nov. 21, 2023

Unveiling the alkyl/Pd hybrid species is a unique sp3-C-centered radical for facilitating intermolecular hydrogen atom transfer (HAT) in development of direct alkylation glycine derivatives. This transformative reaction proceeds smoothly under simple and mild conditions, exhibiting impressive versatility terms substrate scope encompassing both derivatives alkyl bromides while showcasing remarkable tolerance toward diverse functional groups. To shed light on underlying mechanism, extensive investigations involving control experiments, deuterium labeling, clocking, kinetic studies have been conducted. The collected data consistently support pathway formation Pd(I)/alkyl followed by HAT elimination steps that lead to situ imine intermediates, ultimately culminating final stage through addition.

Language: Английский

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Accessing Benzoazepine Derivatives via Photoinduced Radical Relay Formal [5 + 2] Reaction of Amide/Alkyne Enabled by Palladium Catalysis

Organic Letters, Journal Year: 2024, Volume and Issue: 26(13), P. 2662 - 2667

Published: March 26, 2024

A novel class of alkyne-tethered amides facilitates an unprecedented photoinduced palladium-catalyzed radical relay formal [5 + 2] reaction. This innovative strategy allows for the rapid construction diverse fused benzoazepine structures, yielding structurally and compelling compounds. With a broad substrate scope excellent functional group tolerance, methodology synthesizes biologically active Notably, resulting tricyclic benzo[b]azepines offer diversification opportunities through simple transformations. DFT calculations elucidate seven-membered ring closure mechanism involving alkenyl Pd(I) rebound alongside concerted metalation–deprotonation (CMD) process.

Language: Английский

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Photoredox Site-Selective C(sp³)–H Alkylation of 1-(o-Iodoaryl)-alkan-1-ones with Activated Alkenes Enabled by Hydrogen Atom Transfer

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: March 13, 2025

A visible-light-mediated photoredox catalysis for β-C(sp3)–H alkylation of 1-(o-iodoaryl)alkan-1-ones with alkenes via 1,5-hydrogen atom transfer and alkene alkylarylation to produce diverse β-alkyl arylalkanones containing a quaternary carbon center is presented. This method applicable wide range activated alkenes. Mechanistic studies suggest that the reaction involves radical process.

Language: Английский

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Advances in catalysis using Xantphos-like ligands; simplicity goes a long way

Coordination Chemistry Reviews, Journal Year: 2025, Volume and Issue: 537, P. 216636 - 216636

Published: April 11, 2025

Language: Английский

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Photoinduced Palladium-Catalyzed Radical Heck-Type Coupling of Cyclobutanone Oxime Esters with Vinyl Arenes

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(10), P. 7243 - 7254

Published: May 2, 2024

A palladium-catalyzed radical Heck-type coupling reaction of cyclobutanone oxime esters with olefins under visible-light irradiation has been developed. The cyanoalkyl/Pd(I) hybrid species generated by selected ring-opening C–C bond cleavage imino/Pd(I) reacted smoothly vinyl arenes, delivering the cyanoalkylation mild conditions. This elegant strategy a broad scope and functional group tolerance. Subsequently, late-stage functionalization bioactive molecules synthetic transformations product further confirm practicality.

Language: Английский

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Aryl-to-alkyl radical relay arylation reaction of remote C(sp3)-H bond using 1,4-dicyanobenzene as an electrochemical redox-mediator

Organic Chemistry Frontiers, Journal Year: 2024, Volume and Issue: 11(15), P. 4182 - 4186

Published: Jan. 1, 2024

In this paper, we developed an electro-reductive aryl-to-alkyl radical relay arylation reaction of a remote C(sp 3 )–H bond via 1,5-HAT process. This protocol features mild conditions, simple operation, and broad substrate scope.

Language: Английский

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Radical Cyclization-Initiated Difunctionalization Reactions of Alkenes and Alkynes

Molecules, Journal Year: 2024, Volume and Issue: 29(11), P. 2559 - 2559

Published: May 29, 2024

Radical reactions are powerful in the synthesis of diverse molecular scaffolds bearing functional groups. In previous review articles, we have presented 1,2-difunctionalizations, remote 1,3-, 1,4-, 1,5-, 1,6- and 1,7-difunctionalizations, addition followed by cyclization reactions. Presented this paper is radical second functionalization reaction. The could be realized atom transfer reactions, or transition metal-assisted coupling with neutral molecules, cationic anionic species.

Language: Английский

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Modular synthesis of 3,3-disubstituted oxindoles from nitrones and acrylic acids

Organic & Biomolecular Chemistry, Journal Year: 2024, Volume and Issue: 22(31), P. 6282 - 6287

Published: Jan. 1, 2024

We developed a modular synthesis for 3,3-disubstituted oxindoles, utilising readily accessible nitrones and acrylic acids. This approach facilitates the preparation of diverse array oxindoles through variation starting materials. demonstrated applicability this method gram-scale reaction esermethole.

Language: Английский

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Transition‐Metal‐Free Radical Relay Cascade Annulation of Amides: Access to Antitumor Active Benzo[b]azepine and Oxindole Derivatives

Chemistry - A European Journal, Journal Year: 2024, Volume and Issue: 30(63)

Published: Aug. 26, 2024

Abstract Efficient transition‐metal‐free synthesis of benzo[b]azepines and oxindoles is achieved via a radical relay cascade strategy employing halogen atom transfer (XAT) for aryl generation followed by intramolecular hydrogen (HAT). Optimization yielded moderate to substantial yields under visible light irradiation. Preliminary biological assessments revealed promising anti‐tumor activity select compounds. This study underscores the potential XAT‐mediated cascades in medicinal chemistry anticancer drug discovery.

Language: Английский

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Photoinduced Metal-Free Arylboration of Unactivated Alkenes: Synthesis of Indoline Boronic Ester

Synlett, Journal Year: 2023, Volume and Issue: 35(12), P. 1399 - 1404

Published: Sept. 29, 2023

Abstract The environmentally benign synthesis of indoline boronic esters, especially through a way arylboration to alkenes, remains challenge due the use transition metals or high-temperature conditions. We described photoinduced metal-free unactivated alkenes for esters and 1,2,3,4-tetrahydroquinoline ester in good yields. This approach showed compatibility great efficiency range allylphenylamines as well alkylamine. Remarkably, this transformation also suggested that base is not necessary photosensitizer-free diboron reagent mediated mild generation aryl radical. Furthermore, compared previously reported methods, benign.

Language: Английский

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