Electrochemical cascade pyrazole annulation and C-H halogenation for the synthesis of 4-halopyrazoles

Green Synthesis and Catalysis, Journal Year: 2023, Volume and Issue: unknown

Published: Oct. 1, 2023

The synthesis of 4-halo-functionalized pyrazoles by electrochemical cascade reactions between N,N-dimethyl enaminones and proper hydrazine reagents in the presence a halogen source is realized at room temperature. work provides tunable efficient accesses to 4-chloro- 4-bromopyrazoles aqueous THF (tetrahydrofuran) without using any transition metal reagent.

Language: Английский

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Current Developments in Michael Addition Reaction using Heterocycles as Convenient Michael Donors

Asian Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: unknown

Published: July 3, 2024

Abstract The Michael addition reaction, a cornerstone of contemporary organic synthesis, has witnessed resurgence interest owing to its ability forge intricate carbon‐carbon and carbon‐heteroatom bonds. In the past few years, heterocyclic compounds have been rigorously used as donors, their architectural diversity distinct reactivity with or without presence base/transition metals/organocatalysts. This review encapsulates latest breakthroughs in chemistry involving reaction using donors. It delivers comprehensive update on developments triggered by potent heterocycles since 2017, highlighting novel innovative methodologies, strategic insights.

Language: Английский

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A novel pyrazole-pyrazoline fluorescent probe for the detection of Cu2+ and Fe3+ in living cells

Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy, Journal Year: 2024, Volume and Issue: 329, P. 125533 - 125533

Published: Dec. 2, 2024

Language: Английский

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Facile synthesis of 3-(pyrazol-1-yl) succinimides from Ag ₂ CO ₃ -catalyzed aza-Michael addition of pyrazoles to maleimides

Synthetic Communications, Journal Year: 2023, Volume and Issue: 53(24), P. 2088 - 2096

Published: Oct. 26, 2023

Herein, an effective and facile synthesis of 3-(pyrazol-1-yl) succinimides is first presented through silver-catalyzed aza-Michael addition pyrazoles to maleimides. In the presence 5 mol% Ag2CO3, various smoothly reacted with maleimides in dichloroethane at 100 °C, generate excellent yields. Notably, 3-substituted asymmetric exclusively give 3-pyrazolyl yields possibly due steric bulk 3-substituent excluding formation products N2. The method can also extend gram scale.

Language: Английский

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Regio- and Stereoselective Switchable Synthesis of (E)- and (Z)-N-Carbonylvinylated Pyrazoles

Molecules, Journal Year: 2023, Volume and Issue: 28(11), P. 4347 - 4347

Published: May 25, 2023

Regio- and stereoselective switchable synthesis of (E)- (Z)-N-carbonylvinylated pyrazoles is first developed by using the Michael addition reaction conjugated carbonyl alkynes. Ag2CO3 plays a key role in pyrazoles. Ag2CO3-free reactions lead to thermodynamically stable (E)-N-carbonylvinylated excellent yields whereas with give good yields. It noteworthy that or (Z)-N1-carbonylvinylated are obtained high regioselectivity when asymmetrically substituted react The method can also extend gram scale. A plausible mechanism proposed on basis detailed studies, wherein Ag+ acts as coordination guidance.

Language: Английский

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Effective Synthesis of N-Alkyl-3-(Indol-3-yl)Pyrazoles from Ag2CO3-Catalyzed Regioselective Aza-Michael Addition of 5-(Indol-3-yl)-1HPyrazoles

Letters in Organic Chemistry, Journal Year: 2024, Volume and Issue: 21(10), P. 898 - 908

Published: March 12, 2024

Abstract: In this study, the synthesis of N-alkyl-3-(indol-3-yl)pyrazoles was carried out from Ag2CO3 catalyzed regioselective aza-Michael addition 5-(indol-3-yl)-1H-pyrazoles to α, β-unsaturated carbonyl compounds. presence 10 mol% Ag2CO3, reaction smoothly occurred in dichloroethane (DCE) at 120°C preferentially afford a series high yields with good regioselectivity. It found that 1-methyl-3-(3-methyl-1H-pyrazol-5-yl)-2-phenyl- 1H-indole, 1-benzyl-3-(3-methyl-1H-pyrazol-5-yl)-1H-indole, ketone, and β- unsaturated amide exclusively gave 3-(pyrazol-3-yl)indoles yields. This features regioselectivity, mild conditions, substrate scope yields, commercially available catalyst. Meanwhile, also proven be quite practical by gram-scale excellent

Language: Английский

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Modern Approaches to the Synthesis of Pyrazoles (A Review)

Журнал Общей Химии, Journal Year: 2024, Volume and Issue: 94(1), P. 29 - 55

Published: July 2, 2024

Language: Английский

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Synthesis of Highly Substituted 1,2,4-Triazole-Based 3-Nitrochromanes through Aza-Michael Addition Reaction under Catalyst- and Base-Free Conditions

Synthesis, Journal Year: 2023, Volume and Issue: 56(01), P. 151 - 160

Published: Oct. 18, 2023

Abstract A simple and efficient aza-Michael addition reaction of 1,2,4-triazoles to functionalized 2-aryl-3-nitro-2H-chromenes has been demonstrated under catalyst- base-free conditions. In this transformation, one intermolecular C–N bond formation is achieved at room temperature. series highly substituted 1,2,4-triazole-based 3-nitrochromanes were produced in good excellent yields, up 86%. The relative configuration the Michael adducts was confirmed by X-ray crystallographic analysis. High yield, easy accessibility a wide variety functional group tolerance are key features aza-Michael­ reaction.

Language: Английский

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