Photoinduced Electron Transfer from Xanthates to Acyl Azoliums: Divergent Ketone Synthesis via N‐Heterocyclic Carbene Catalysis

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(32)

Published: June 12, 2023

Considering the prevalence of alcohols and carboxylic acids, their fragment cross-coupling reactions could hold significant implications in organic synthesis. Herein, we report a versatile method for synthesizing diverse range ketones from acid derivatives via N-heterocyclic carbene (NHC) catalysis. Mechanistic investigations revealed that photoexcited xanthates acyl azoliums undergo single electron transfer (SET) under photocatalyst-free conditions, generating NHC-derived ketyl radicals alkyl radicals. These open-shell intermediates subsequently radical-radical reaction, yielding valuable ketones. Furthermore, this approach can be employed three-component involving alkenes enynes, resulting structurally cross-coupled The unified strategy offers unique opportunity coupling derivatives, accommodating functional groups even complex settings.

Language: Английский

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Recent advances in three-component radical acylative difunctionalization of unsaturated carbon–carbon bonds

Organic Chemistry Frontiers, Journal Year: 2023, Volume and Issue: 10(18), P. 4488 - 4515

Published: Jan. 1, 2023

This review highlights the recent advances in radical acylated difunctionalization of unsaturated carbon–carbon bonds and focuses on mechanistic insights these transformations.

Language: Английский

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Carbene‐Catalyzed Intermolecular Dehydrogenative Coupling of Aldehydes with C(sp³)−H Bonds

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(23)

Published: April 5, 2023

The development of catalyst-controlled methods for direct functionalization two distinct C-H bonds represents an appealing approach C-C formations in synthetic chemistry. Herein, we describe organocatalytic straightforward acylation C(sp3 )-H employing readily available aldehyde as "acyl source" involving dehydrogenative coupling aldehydes with ether, amine, or benzylic bonds. developed method affords a broad range ketones under mild conditions. Mechanistically, simple ortho-cyanoiodobenzene is essential the oxidative radical N-heterocyclic carbene catalysis to give ketyl and ) through rarely explored intermolecular hydrogen atom transfer pathway, rendering acylative high efficiency metal- light-free catalytic Moreover, prepared products show promising anti-bacterial activities that shall encourage further investigations on novel agrochemical development.

Language: Английский

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Remote Radical 1,3-, 1,4-, 1,5-, 1,6- and 1,7-Difunctionalization Reactions

Molecules, Journal Year: 2023, Volume and Issue: 28(7), P. 3027 - 3027

Published: March 28, 2023

Radical transformations are powerful in organic synthesis for the construction of molecular scaffolds and introduction functional groups. In radical difunctionalization reactions, radicals first functionalized intermediates can be relocated through resonance, hydrogen atom or group transfer, ring opening. The resulting undertake following paths second functionalization: (1) couple with other groups, (2) oxidize to cations then react nucleophiles, (3) reduce anions electrophiles, (4) metal-complexes. rearrangements provide opportunity 1,3-, 1,4-, 1,5-, 1,6-, 1,7-difunctionalization products. Multiple ways initiate reaction coupling intermediate make reactions good at remote positions. These offer advantages synthetic efficiency, operation simplicity, product diversity.

Language: Английский

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Organocatalytic radical relay trifunctionalization of unactivated alkenes by a combination of cyano migration and alkylacylation

Chemical Communications, Journal Year: 2023, Volume and Issue: 59(36), P. 5395 - 5398

Published: Jan. 1, 2023

The first N-heterocyclic carbene organocatalytic three-component radical relay trifunctionalization of unactivated alkenes through the combination remote 1,4-cyano migration and alkylacylation was reported. This protocol features mild reaction conditions, readily available materials, excellent regioselectivity, capability late-stage functionalization.

Language: Английский

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Photoinduced copper-catalyzed asymmetric radical three-component cross-coupling of 1,3-enynes with oxime esters and carboxylic acids

Organic Chemistry Frontiers, Journal Year: 2023, Volume and Issue: 10(11), P. 2773 - 2781

Published: Jan. 1, 2023

A regio- and enantioselective radical three-component coupling of 1,3-enynes, oxime esters, carboxylic acids through photoinduced copper catalysis is reported.

Language: Английский

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Synthesis of Trifluoromethyl-Substituted Allenols via Catalytic Trifluoromethylbenzoxylation of 1,3-Enynes

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(3), P. 2142 - 2148

Published: Jan. 25, 2023

Allenol has been identified as a versatile building block for organic synthesis, and numerous efforts have made to synthesize apply allenol. However, limited obtain trifluoromethyl-substituted Here, by using readily available 1,3-enyne the starting material, copper-catalyzed trifluoromethylbenzoxylation process was developed efficient synthesis of allenols Togni-II reagent reaction partner. Triple roles reagent, including source trifluoromethyl group, hydroxyl oxidant, were elucidated in this transformation. Moreover, late-stage diversification performed, which revealed application potential preparation various compounds.

Language: Английский

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NHC-Catalyzed Synthesis of α-Sulfonyl Ketones via Radical-Mediated Sulfonyl Methylation of Aldehydes

Organic Letters, Journal Year: 2023, Volume and Issue: 25(15), P. 2657 - 2662

Published: April 11, 2023

An N-heterocyclic carbene (NHC)-catalyzed facile assembly of α-sulfonyl ketones has been successfully developed through a radical-mediated sulfonyl methylation readily available aldehydes. This protocol involves the effective single-electron transfer reduction α-iodosulfones by NHC-bound Breslow intermediates, thus allowing subsequent radical-radical coupling to afford target compounds. Moreover, catalytic system was found be equally for difunctionalization styrenes and 1,3-enynes via three-component radical relay process.

Language: Английский

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Visible light-mediated NHC and photoredox co-catalyzed 1,2-sulfonylacylation of allenesviaacyl and allyl radical cross-coupling

Organic Chemistry Frontiers, Journal Year: 2023, Volume and Issue: 10(4), P. 1047 - 1055

Published: Jan. 1, 2023

Visible light-mediated NHC and photoredox co-catalyzed radical 1,2-sulfonylacylation of allenes via cross-coupling between an allyl NHC-stabilized acyl radical.

Language: Английский

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Radical Acylation of Alkenes by NHC‐Organocatalysis

European Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 26(48)

Published: Oct. 11, 2023

Abstract N ‐Heterocyclic carbene (NHC) catalyzed radical‐radical reactions have been proven to be powerful strategies for assembling ketyl‐containing compounds via single electron transfer (SET) pathway under either thermal conditions or photoredox conditions. In this context, acylation of alkenes radical relay NHC‐organocatalysis has also opened a new window the difunctionalization construct valuable molecules in organic synthesis. review, advances and progress were summarized according different ways generation key NHC‐bound ketyl‐type radicals. Furthermore, reaction scopes, limitations mechanisms discussed based on types catalytic systems. Conclusions perspectives put forward at end.

Language: Английский

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