Convenient synthesis of 6-Amino-2-naphthol by Copper-catalyzed Ullmann reaction

Jagushte, Kaustubh U.; Ketkar, Rohit N.; Thakkar, Chinmay; Choudhury, Sharmistha Dutta; Sadhukhan, Nabanita

doi:10.1016/j.tetlet.2023.154693

Cited by 3 publications

(3 citation statements)

References 47 publications

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“…The bifunctional photoacid, 6-amino-2-naphthol (6N2OH) and the reference molecule, 6-amino-2-methoxynaphthalene (6N2M), were synthesized according to the procedure reported previously, by following a cascade reaction scheme (Chart 2) in which a modified CuSO 4 •5H 2 O-catalyzed Ullmann-type reaction was used for the amination step. 35 Briefly, 2-bromo-6methoxy naphthalene (0.5 g) was reacted with NaN 3 (0.41 g) in DMSO (7 mL), in the presence of CuSO 4 •5H 2 O (0.21 g), Naascorbate (0.5 g), L-proline (0.16 g), and NaOH (0.054 g), for 29 h at 120 °C under inert conditions. The reaction mixture was then quenched with ice-cold water and extracted with EtOAc, followed by column chromatography to obtain 6N2M in 61% yield.…”

Section: Methodsmentioning

confidence: 99%

“…Given the application of photoacids in many biochemical processes, understanding the photophysics and tunability of photoacidity by varying structural, solvent, or pH parameters is of considerable importance, and the present study attempts to contribute in this regard. The 6N2OH derivative along with an analogous molecule, 6-amino-2-methoxynaphthalene (6N2M; Chart 1B), have been obtained by tandem chemical synthesis; 35 the latter for use as a reference photoacid to corroborate the ESPT pathways in 6N2OH. The experimental results obtained through absorption, emission and time-resolved fluorescence studies are supported by time-dependent density functional theory (TD-DFT) calculations.…”

Section: Introductionmentioning

confidence: 99%

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Dual Excited State Proton Transfer Pathways in the Bifunctional Photoacid 6-Amino-2-naphtol

Jagushte,

Sadhukhan,

Upadhyaya

et al. 2023

J. Phys. Chem. B

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This study investigates the photoacidity and excited state proton transfer (ESPT) pathways of a bifunctional molecule, 6amino-2-naphthol (6N2OH), using absorption, steady-state fluorescence, time-resolved fluorescence, and theoretical calculations. 6N2OH attains four different prototropic forms in the excited state (cation, neutral, anion, or zwitterion) depending on pH of the solution. Interestingly, ESPT at the OH site of the molecule can be controlled by the protonation state of the amino substituent. Conversion of the electron donating NH 2 group to the electron withdrawing NH 3+ group brings about a reduction of more than 7 pK a units for the deprotonation of OH in the excited state. Further, the position of the NH 2 substituent on the naphthalene framework is found to play an important role in dictating the ESPT pathways of aminonaphthols. Unlike most aminonaphthol derivatives that undergo ESPT only at the OH site, akin to substituted naphthols, 6N2OH undergoes ESPT at both OH and NH 3 + sites, indicating its similarity to substituted naphthols and substituted naphthylamines. ESPT at the NH 3 + site resulting in cation ↔ neutral equilibrium of 6N2OH in the excited state is well-corroborated by comparative studies with another reference photoacid, 6-amino-2-methoxynaphthalene (6N2M). Correlation of the acidity constants of 6N2OH with the σ p parameters according to the Hammett model reveals that while 6N2OH can be treated either as naphthol or as naphthylamine in the ground state, the structure−function correlation cannot be extrapolated directly in the excited state, thus highlighting the rich and complex photophysics of bifunctional photoacids.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Dual Excited State Proton Transfer Pathways in the Bifunctional Photoacid 6-Amino-2-naphtol

Jagushte,

Sadhukhan,

Upadhyaya

et al. 2023

J. Phys. Chem. B

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“…Following the acquisition of 11 and 11', an Ullmann reaction was conducted to facilitate the coupling of a benzene ring onto the exposed hydroxyl group, [27,28] as depicted in Scheme 3. Subsequently, phenolic hydroxy compounds 14 and 14' were obtained through a demethylation reaction employing boron tribromide.…”

Section: Chemistrymentioning

confidence: 99%

Synthesis, and Insecticidal Activities of Propargyloxy‐Diphenyl Oxide‐Sulfonamide Derivatives

Wang,

Guo,

Zhou

et al. 2024

Chemistry & Biodiversity

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Agricultural pests are the primary contributing factor to crop yield reduction, particularly in underdeveloped regions. Despite the significant efficacy of pesticides in pest control, their extensive use has led to the drug‐fast of insecticide resistance. Developing of new environmentally friendly plant‐based pesticides is an urgent necessity. In this study, a series of diaryl ether compounds containing propargyloxy and sulfonamide groups were designed. The synthesis of these 36 compounds primarily relied on nuclear magnetic resonance for structure determination, while single‐crystal X‐ray diffraction was employed for certain compounds. Meanwhile, the insecticidal activities against Mythimna separata were also assessed. Some of the compounds exhibited significantly enhanced activity, the LC50 value of the highest activity compound TD8 (0.231 mg/mL) demonstrating respective increases by 100‐fold compared to the plant pesticide celangulin V (23.9 mg/mL), and a 5‐fold increase with the positive control L‐1 (1.261 mg/mL). The interaction between the target compound and the target, as well as the consistency of the target, were verified through symptomological analysis and molecular docking. The structure‐activity relationships were also conducted. This study offered a novel trajectory for the advancement and formulation of future pesticides.

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Catalysed Aryl Amine Syntheses via Azides: From Azidation of Aryl Halides to Azide Reduction and Direct Amination

Roemer

2024

ChemCatChem

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This review summarises and discusses aryl amine and azide syntheses from aryl halides employing azides. The majority of the reported reactions proceed with copper catalysis or mediation. Often, an aryl azide is formed in the first step, which is then reduced in situ to an aryl amine in a second step. The occurrence of the second step, the reduction, depends on the chosen reaction conditions and the substrates. The formation of only aryl azides through Cu‐mediated C–N bond formations is discussed, followed by mediated and catalytic aryl azide reduction employing different catalytic systems, and azidation with in situ azide reduction to amines, viz. azidation‐amination strategies. The azidation‐amination allows for the synthesis of complex heterocycles in multi‐step one‐pot procedures, of which several are summarised here. Examples of the application of azidation‐amination for synthesising important aryl amines employed in or as biologically active compounds, catalysis and materials science are also summarised. Finally, conducted control reactions have been collected and discussed in combination with mechanistic proposals. This literature survey allows us to pinpoint design criteria for the azide reduction to valuable amines, which includes the choice of reaction conditions such as solvent system and additives, involved metal and promising substrates.

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Convenient synthesis of 6-Amino-2-naphthol by Copper-catalyzed Ullmann reaction

Cited by 3 publications

References 47 publications

Dual Excited State Proton Transfer Pathways in the Bifunctional Photoacid 6-Amino-2-naphtol

Dual Excited State Proton Transfer Pathways in the Bifunctional Photoacid 6-Amino-2-naphtol

Synthesis, and Insecticidal Activities of Propargyloxy‐Diphenyl Oxide‐Sulfonamide Derivatives

Catalysed Aryl Amine Syntheses via Azides: From Azidation of Aryl Halides to Azide Reduction and Direct Amination

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