Regio- and Stereoselective Synthesis of 3-Selenylazaflavanones and 3-Selenylflavanones via Electrochemically Facilitated Selenylation Cascade

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(6), P. 4074 - 4084

Published: Feb. 23, 2024

Herein, an oxidant- and metal-free electrochemical selenylation reaction of chalcones with diselenides for the synthesis 3-selenylazaflavanones 3-selenylflavanones at room temperature was reported. The method proceeded under mild conditions, exhibited a broad substrate scope, provided selenylated products in moderate to excellent yields high regio- stereoselectivity. could also be readily scaled up efficiency. Detailed mechanistic studies through control experiments disclosed that selenium-based radical might participate this transformation.

Language: Английский

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Direct Functionalization of para‐Quinones: A Historical Review and New Perspectives

European Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 27(27)

Published: May 21, 2024

Abstract The direct functionalization of quinones has always fascinated research communities due to their biological and redox activities subsequent application. Quinone motifs play a vital role as precursors for many bioactive compounds materials; hence, ingenious methodologies have been elaborated exploring these units. A significant part the synthetic strategies towards functionalized achieved by installing substituents on hydroquinones, phenols, or quinone itself different oxidative coupling reactions via radical pathways with without utilization metal catalysts. simple C−H bond remains challenging inherited electronic nature high dissociation energy. This review article summarizes recent advancement made through quinones. Our primary focus will be approaches mechanistic that appeared in last two decades, along short historical importance family.

Language: Английский

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Blue Light Irradiated Metal-, Oxidant-, and Base-Free Cross-Dehydrogenative Coupling of C(sp²)–H and N–H Bonds: Amination of Naphthoquinones with Amines

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(11), P. 7401 - 7424

Published: May 12, 2023

Herein, we report a blue-light-driven amination of C(sp2)-H bond naphthoquinones and quinones with the N-H primary secondary amines for synthesis 2-amino-naphthoquinones 2-amino-quinones. The coupling wide array aliphatic, aromatic, chiral, primary, having electron donating (-CH3, -OCH3, -SCH3), withdrawing (-F, -Cl, -Br, -I), CO2H, -OH, -NH2 groups acidic protons selectively occurred to afford C-N coupled in 60-99% yields hydrogen gas as byproduct methanol solvent without using any additional reagents, additives, oxidant under blue light irradiation. Mechanistic insight by DFT computation, controlled experiments, kinetic isotopic effect, substitution effect substrates suggest that reaction proceeds radical pathway which naphthoquinone forms highly oxidizing naphthoquinonyl biradical upon irradiation (457 nm). Consequently, transfer from electron-rich amine an leads anion aminyl cation, followed proton delocalization leading carbon-centered radical. cross-coupling nitrogen radicals bond, subsequent elimination (which was also confirmed GC-TCD), affording 2-amino-1,4-naphthoquinone metal-, reagent-, base-, oxidant-free conditions.

Language: Английский

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Electrochemical Synthesis of Organoselenium Compounds: A Graphical Review

SynOpen, Journal Year: 2023, Volume and Issue: 07(04), P. 511 - 520

Published: Oct. 1, 2023

Abstract Electrochemical synthesis, due to its environmentally benign, sustainable, and practical nature, has become an appealing powerful substitute for traditional methods oxidizing reducing organic compounds. Thus, numerous valuable changes have been established in the field of synthesis through utilization electrochemistry. Among these electrochemical transformations, formation C–Se bonds stands out as exceptionally noteworthy reaction type. In this graphical review, we present a succinct summary progress utilizing strategies synthesizing organoselenium

Language: Английский

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Electrochemical Annulation of ortho‐Alkynylbiphenyls to Fused Sulfenyl Phenanthrenes and Spiro Cyclohexenone Indenes

Advanced Synthesis & Catalysis, Journal Year: 2023, Volume and Issue: 366(1), P. 18 - 23

Published: Nov. 21, 2023

Abstract Here, we present an electrochemically induced synthesis of 9‐sulfenylarylphenanthrenes and 3’‐sulfenylarylspiro‐cyclohexa[4.5]trienones starting from o ‐alkynylbiphenyls diaryl disulfides. This method was accomplished through constant current electrolysis 10 mA in undivided cell setup by utilizing CH 3 CN as a solvent LiClO 4 electrolyte at room temperature. Notably, the strategy enabled formation sulfenylphenanthrenes sulfenyl spiro cyclohexa[4.5]trienones 70%–95% yield. Scale‐up synthesis, mechanistic studies, cyclic voltammetry have also been carried out.

Language: Английский

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Electrochemical Regioselective C(sp2)-H Bond Chalcogenation of Pyrazolo[1,5-a]pyrimidines via Radical Cross Coupling at Room Temperature

Published: April 9, 2024

In this report, we disclose an electrochemical approach for the C(sp2)-H chalcogenation of pyrazolo[1,5-a]pyrimidines at room temperature via radical cross-coupling reaction. The reaction takes place within undivided cell employing graphite electrodes, with TBABF4 acting as supporting electrolyte. This technique offers a rapid, oxidant-free, and environmentally conscious protocol achieving regioselective specifically C3 position pyrazolo[1,5-a]pyrimidines. Furthermore, procedure uses only 0.5 equivalents diaryl chalcogenides which underscores atom economy protocol. Key attributes methodology include mild conditions, short time, utilization cost-effective electrode materials, reliable achievement yields ranging from good to excellent friendly conditions. Cyclic voltammetry studies quenching experiments suggest pathway mechanism.

Language: Английский

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Oxidative Aminotrifluoromethylation of 1,4-Naphthoquinone

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(18), P. 13117 - 13127

Published: Sept. 3, 2024

A strategy for convenient and precise oxidative aminotrifluoromethylation of 1,4-naphthoquinone with the Togni reagent amines has been demonstrated via a radical process. This method allows efficient access preparation wide range CF

Language: Английский

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PhI(OAc)₂/I₂‐Mediated Decarboxylative C₄‐Amination of Coumarin‐3‐Carboxylic Acids via C_sp2−H Dehydrogenative C−N Cross‐Coupling under Ambient Conditions

European Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 26(15)

Published: March 6, 2023

Abstract An efficient and straightforward protocol for accessing a new series of functionalized 4‐aminocoumarins from PIDA/I 2 ‐mediated decarboxylative C 4 ‐amination coumarin‐3‐carboxylic acids via direct sp2 −H dehydrogenative C−N cross‐coupling with secondary amines under ambient conditions has been accomplished. The notable advantages this are the tolerance diverse functional groups, mild reaction at temperature, moderate to good yields, short times (in minutes), high regioselectivity, gram‐scale applicability, eco‐friendliness. This is first report cross‐dehydrogenative coupling synthesizing 4‐aminocoumarins.

Language: Английский

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Mechanochemical Solvent‐Free One‐Pot Synthesis of Poly‐Functionalized 5‐(Arylselanyl)‐1H‐1,2,3‐triazoles Through a Copper(I)‐Catalyzed Click Reaction

Chemistry - A European Journal, Journal Year: 2023, Volume and Issue: 29(63)

Published: Sept. 4, 2023

A mechanochemistry-driven practical and efficient synthetic protocol for accessing diverse series of biologically relevant poly-functionalized 5-(arylselanyl)-1H-1,2,3-triazoles through copper(I)-catalyzed click reaction between aryl/heteroaryl acetylenes, diaryl diselenides, benzyl bromides, sodium azide has been accomplished under high-speed ball-milling. Advantages this method include operational simplicity, avoidance using solvent external heating, one-pot synthesis, short time in minutes, good to excellent yields, broad substrate scope, gram-scale applications. Furthermore, synthesized organoselenium compounds were synthetically diversified promising selenones.

Language: Английский

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Ultrasound-Assisted Catalyst-Free Knoevenagel Condensation of Carbonyl Compounds with C – H Acids in Water

Current Green Chemistry, Journal Year: 2023, Volume and Issue: 11(2), P. 210 - 220

Published: Oct. 16, 2023

Abstract: An ultrasound-assisted catalyst-free green protocol has been developed for the synthesis of a series diversely substituted Knoevenagel condensation products from reaction between functionalized aromatic aldehydes/isatin derivatives and malononitriles as C-H acids in water at ambient conditions. The method is simple, straightforward, highly efficient. major advantages this newly are expedient synthesis, good to excellent yields, energy efficiency, use medium, easy isolation products, no need column chromatographic purification, eco-friendliness, operational simplicity.

Language: Английский

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