Unveiling N-Fused Nitreniums as Potent Catalytic Photooxidants

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(6), P. 3603 - 3608

Published: Jan. 31, 2024

The first example of a hitherto-unknown facet catalytic photooxidant capability nitrenium cations is reported herein. fundamental limitation inability the traditional and nitreniums to achieve excited-state redox potential beyond +2.0 V (vs Ag/AgCl), primary requirement for powerful photooxidant, addressed in this work by developing structurally unique class N-fused cations, with required structural engineering involving extensive π-conjugation through ring fusion at site, which enabled significant lowering LUMO energy easy reduction excited state (excited-state up +2.5 vs facilitated effective delocalization/stabilization generated radical. This finding opens new way discover novel useful (photo)catalytic properties just Lewis acidity.

Language: Английский

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Visible-Light Photocatalytic C–H Amination of Arenes Utilizing Acridine–Lewis Acid Complexes

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(21), P. 14799 - 14806

Published: May 17, 2024

This report describes the development of a visible-light photocatalytic system for C(sp2)–H amination that leverages in situ-generated photocatalysts. We demonstrate combination acridine derivatives and Lewis acids forms potent photooxidants promote C–H electronically diverse arenes upon irradiation with (440 nm). A first-generation photocatalyst composed Sc(OTf)3 effects substrates oxidation potentials ≤ +2.5 V vs SCE pyrazole, triazole, pyridine nucleophiles. Furthermore, simplicity modularity this enable variation both acid to tune reactivity. enabled rapid identification two second-generation photocatalysts (derived from (i) Al(OTf)3 or (ii) pyridinium-substituted acridine) catalyze particularly challenging transformation: benzene as limiting reagent.

Language: Английский

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Tethering Three Radical Cascades for Controlled Termination of Radical Alkyne peri-Annulations: Making Phenalenyl Ketones without Oxidants

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(6), P. 4187 - 4211

Published: Feb. 5, 2024

Although Bu3Sn-mediated radical alkyne peri-annulations allow access to phenalenyl ring systems, the oxidative termination of these cascades provides only a limited selection possible isomeric phenalenone products with product selectivity controlled by intrinsic properties new cyclic systems. In this work, we report an oxidant-free strategy that can overcome limitation and enable selective full set isomerically functionalized phenalenones. The key preferential is preinstallation "weak link" undergoes C–O fragmentation in final cascade step. Breaking bond assisted entropy, gain conjugation product, release stabilized fragments. This expanded exo-dig cyclization oligoalkynes, which provide π-extended Conveniently, introduce functionalities (i.e., Bu3Sn iodide moieties) amenable further cross-coupling reactions. Consequently, variety polyaromatic diones, could serve as phenalenyl-based open-shell precursors, be synthesized.

Language: Английский

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A fruitful century for the scalable synthesis and reactions of biphenyl derivatives: applications and biological aspects

RSC Advances, Journal Year: 2023, Volume and Issue: 13(27), P. 18262 - 18305

Published: Jan. 1, 2023

This review provides recent developments in the current status and latest synthetic methodologies of biphenyl derivatives.

Language: Английский

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Radical Substitution of Polyfluoroarenes and Heteroarenes Promoted by Photoredox Activation of Organozinc Iodides

Advanced Synthesis & Catalysis, Journal Year: 2023, Volume and Issue: 365(19), P. 3387 - 3391

Published: Sept. 12, 2023

Abstract Aromatic compounds interact with organozinc reagents under photoredox conditions, leading to the substitution products. The reaction is performed blue light irradiation via in situ generated (Barbier conditions), which are oxidized by photocatalyst, followed radical attack at aromatic substrate. method works polyfluorinated arenes, 2‐chlorobenzoxazoles, and 2‐sulfonyl‐substituted benzothiazole.

Language: Английский

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Investigating the Potency of a Phenalenyl-Based Photocatalyst under the Photoelectrochemical Condition for Intramolecular C–S Bond Formation

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(2), P. 907 - 920

Published: Jan. 4, 2024

Implementation of an organic molecular photocatalyst for photoelectrochemical (PEC) transformations has been a highly demanding aspect that not yet mapped out extensively. Herein, we have unveiled the efficacy phenalenyl-based toward intramolecular C–S bond construction reactions under mild conditions. This phenalenyl core, which contains vacant NBMO, acts as electron reservoir, thereby facilitating formation contact ion pair with electron-rich systems through transfer photoexcitation and aiding in catalytic regeneration by anodic oxidation single pot. Detailed mechanistic investigation using UV–visible spectral analysis, cyclic voltammetry experiments, computational calculations revealed prior EDA complex between substrate triggers this PEC process. unified strategy was successfully implemented six different to synthesize heterocycles make protocol appealing synthesis bonds.

Language: Английский

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Direct Site‐Selective Difunctionalization of Pyrazoles

Advanced Synthesis & Catalysis, Journal Year: 2024, Volume and Issue: 366(5), P. 1090 - 1095

Published: Jan. 15, 2024

Abstract This study presents a protocol for the direct site‐selective difunctionalization of pyrazoles under mild reaction conditions. showcase notable site‐selectivity and encompasses wide substrate scope. Detailed mechanistic investigations elucidate dual role sulfonium salt acting both as acid donor, thereby effectively catalyzing reaction. The demonstrated one‐pot synthesis, scale‐up subsequent product modifications can assist in advancing potential application this organic synthesis its associated domains.

Language: Английский

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Photo/electrocatalytic site-selective C–H functionalization of 8-aminoquinolines and their analogues

Green Chemistry, Journal Year: 2023, Volume and Issue: 25(21), P. 8385 - 8410

Published: Jan. 1, 2023

In this review, 8-aminoquinoline, 8-hydroxyquinoline, and 1-naphthylamine scaffolds are classified, the constructions of their selective C–H activation systems reviewed in terms photocatalytic electrocatalytic synthesis.

Language: Английский

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Photocatalytic One-Pot Three-Component Reaction for the Regioselective Synthesis of Bromo-Substituted Pyrazoles

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(22), P. 16809 - 16827

Published: Nov. 1, 2024

A photocatalytic three-component cascade reaction of readily available enaminones, hydrazines, and CBr4 for the synthesis bromo-substituted pyrazoles in one pot has been demonstrated. This strategy involves intermolecular C-N/C-Br bond formation represents an efficient approach to construction 4-bromo-substituted with high regioselectivity, broad substrate scope, good functional group tolerance, convenient operation, mild conditions. Mechanistic investigations show that this proceeds via cyclization enaminones followed by a regioselective bromination using as "Br" source.

Language: Английский

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Unveiling the potency of a phenalenyl-based photocatalyst for intramolecular dehydrogenative lactonization

Organic Chemistry Frontiers, Journal Year: 2023, Volume and Issue: 11(1), P. 106 - 112

Published: Nov. 7, 2023

Here, an intramolecular dehydrogenative lactonization reaction has been accomplished using a phenalenyl-based organic photocatalyst.

Language: Английский

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