Recent advances in transition metal-free annulation toward heterocycle diversity based on the C–N bond cleavage of enaminone platform

Organic & Biomolecular Chemistry, Journal Year: 2022, Volume and Issue: 20(12), P. 2356 - 2369

Published: Jan. 1, 2022

Enaminones and analogous stable enamines are well known as platform building blocks in organic synthesis for the construction of heterocyclic compounds, especially N-heterocycles. To date, enaminones have been successfully employed various 5- or 6- membered heterocycles. Recently, synthetic protocols accomplished by diversity-oriented annulation reactions based on C-N bond cleavage gained notable success. In this review, development transition metal-free product featuring a is reviewed.

Language: Английский

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A Strategy for Accessing Trifluoromethyl Carbinol-Containing Chromones from o-Hydroxyaryl Enaminones and Trifluoroacetaldehyde/Ketone Derivatives

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(9), P. 5586 - 5596

Published: April 6, 2023

Herein, we present a practical strategy for the direct construction of structurally diverse trifluoromethyl carbinol-containing compounds, especially CF3-substituted tertiary alcohol with chromone derivatives from easily available o-hydroxyaryl enaminones and trifluoroacetaldehyde/ketone under metal-free conditions. This reaction features broad substrate scope good yields is scaled up. Notably, one-pot in two-steps obtained products amidines also developed to provide series multi-substituted pyrimidine bearing two unique hydroxyls one containing functional units.

Language: Английский

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Pd-Catalyzed Triple-Fold C(sp²)–H Activation with Enaminones and Alkenes for Pyrrole Synthesis via Hydrogen Evolution

Organic Letters, Journal Year: 2021, Volume and Issue: 23(11), P. 4363 - 4367

Published: May 20, 2021

The synthesis of NH-free pyrroles via Pd-catalyzed annulation enaminones and alkenes is reported. With the catalysis Pd(II), activation triple C(sp2)-H bonds, including one internal bond in enaminone, has been activated to provide various pyrroles. interesting evolution hydrogen gas from reactions observed by a detector.

Language: Английский

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Metal-Free Photosynthesis of Alkylated Benzimidazo[2,1-a]isoquinoline-6(5H)-ones and Indolo[2,1-a]isoquinolin-6(5H)-ones in PEG-200

The Journal of Organic Chemistry, Journal Year: 2021, Volume and Issue: 86(13), P. 9055 - 9066

Published: June 23, 2021

A visible-light-induced decarboxylation reaction was developed for the synthesis of alkylated benzimidazo[2,1-a]isoquinoline-6(5H)-ones and indolo[2,1-a]isoquinolin-6(5H)-ones under metal-free conditions. Impressively, metal catalysts traditionally volatile organic solvents could be effectively avoided.

Language: Английский

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Preparation of Thiazole-2-thiones through TBPB-Promoted Oxidative Cascade Cyclization of Enaminones with Elemental Sulfur

Organic Letters, Journal Year: 2021, Volume and Issue: 23(8), P. 3076 - 3082

Published: March 26, 2021

An unprecedented method for the construction of thiazole-2-thiones via an oxidative cascade cyclization strategy is described. The novel protocol involves simultaneous formation two C—S bonds and a C═S bond on structure enaminones in single operation through C(sp2)—H/C(sp3)—H sulfurations C(sp3)–H thiocarbonylation. This transformation allows efficient synthesis with broad tolerance moderate to excellent yields from simple elemental sulfur.

Language: Английский

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Copper-catalyzed C–H/N–H annulation of enaminones and alkynyl esters for densely substituted pyrrole synthesis

Chemical Communications, Journal Year: 2022, Volume and Issue: 58(11), P. 1808 - 1811

Published: Jan. 1, 2022

Herein, the copper-catalyzed annulation of enaminones with alkynyl esters for facile synthesis different pyrroles a 2,3,4,5-tetrasubstituted structure has been developed. With Cu(OAc)2 as only catalyst, tunable 2-vinyl and 2,3-dicarboxyl-functionalized achieved by using terminal internal esters, respectively. The represents first example accessing substituted via direct cascade reactions involving vinylation pyrrole ring formation.

Language: Английский

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Recent advances in transition metal-catalyzed transformations in N,N-disubstituted enaminones

Tetrahedron Letters, Journal Year: 2023, Volume and Issue: 130, P. 154766 - 154766

Published: Sept. 26, 2023

Language: Английский

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Transition metal-free tunable synthesis of 3-(trifluoromethylthio) and 3-trifluoromethylsulfinyl chromones via domino C-H functionalization and chromone annulation of enaminones

Chinese Chemical Letters, Journal Year: 2024, Volume and Issue: 35(11), P. 109683 - 109683

Published: March 2, 2024

Language: Английский

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Silver‐catalyzed Cascade Bis‐heteroannulation Reaction of Enynones and o‐Hydroxyphenyl Enaminones: Access to Highly Functionalized 3‐Furylmethyl Chromones

Advanced Synthesis & Catalysis, Journal Year: 2024, Volume and Issue: 366(10), P. 2363 - 2369

Published: March 16, 2024

Abstract A synthetic protocol was developed to synthesize highly functionalized 3‐furylmethyl chromones from enynones and o ‐hydroxyphenyl enaminones via silver‐catalyzed cascade bis‐heteroannulation reaction. This strategy features broad substrate scope good functional group tolerance. Furthermore, the chromone skeleton shows potential application value through further gram‐scale synthesis derivatization.

Language: Английский

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Selective synthesis of pyridazin-fused chromones and 3-pyridazinyl chromones through intermolecular chromone annulation of o-hydroxyphenylenaminones with aryldiazonium salts

Organic Chemistry Frontiers, Journal Year: 2024, Volume and Issue: 11(14), P. 3906 - 3912

Published: Jan. 1, 2024

A chemodivergent and skeleton-controllable annulation reactions of readily available o -HPEs aryldiazonium salts was described for the synthesis highly functionalized pyridazine-fused chromones with high antiviral activity higher safety.

Language: Английский

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