Regioselective synthesis of indazolo[2,3-a]quinazolines enabled by I₂/S-facilitated annulation relay dehydrogenative aromatization of cyclohexanones

Chemical Communications, Journal Year: 2023, Volume and Issue: 59(93), P. 13835 - 13838

Published: Jan. 1, 2023

A method for concise and regioselective synthesis of indazolo[2,3- a ]quinazolines has been developed via sequential annulation dehydrogenative aromatization cyclohexanones.

Language: Английский

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Regioselective synthesis of 3,4-diarylpyrimido[1,2-b]indazole derivatives enabled by iron-catalyzed ring-opening of styrene oxides

Chemical Communications, Journal Year: 2024, Volume and Issue: unknown

Published: Jan. 1, 2024

The first synthesis of 3,4-diarylpyrimido[1,2- b ]indazole derivatives enabled by the epoxide-opening reaction with 3-aminoindazoles has been realized.

Language: Английский

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Synthesis of 2,3-Benzobicyclo[3.3.1]non-2-enes via a Cascade of Domino Carbocation Migration/Interrupted Ritter Reaction and Dienone-Phenol Rearrangement

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(19), P. 14520 - 14526

Published: Sept. 19, 2024

The 2,3-benzobicyclo[3.3.1]non-2-ene scaffold is a bridged backbone of many bioactive natural products. development concise tactic toward this architecture keen interest and highly challenging. Herein, we disclose novel cascade protocol for realizing target. This approach relies on domino sequence carbocation rearrangement Ritter reaction the taiwaniaquinoid derivatives. A process dienone-phenol was postulated to be involved. Several potentially useful compounds with intricate ring were obtained in good overall yields (59-83%, over 2 steps).

Language: Английский

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Transforming an azaarene into the spine of fusedbicyclics via cycloaddition-induced scaffold hopping of 5-Hydroxypyrazoles

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: Dec. 30, 2024

Skeleton editing for heteroarenes, especially pyrazoles, is challenging and remains scarce because these non-strained aromatics exhibit inert reactivities, making them relatively inactive performing a dearomatization/cleavage sequence. Here, we disclose cycloaddition-induced scaffold hopping of 5-hydroxypyrazoles to access the pyrazolopyridopyridazin-6-one skeleton through single-operation protocol. By converting five-membered aza-arene into five-unit spine 6/6 fused-bicyclic, this work unlocks ring-opening reactivity pyrazole core that involves formal C = N bond cleavage while retaining highly reactive N-N in resulting product. A [4 + 2] cycloaddition temporarily dearomatized 5-hydroxypyrrole with an situ generated aza-1,3-diene, followed by oxidative C-N cleavage, constitutes domino pathway. library pyrazolopyridopyridazin-6-ones, which are medicinally relevant nitrogen-atom-rich tricyclics, obtained efficiently from readily available materials.

Language: Английский

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I2/DMSO-mediated substrate selective oxidation of tetrahydro indole2,4-dione towards 4-hydroxy isatins and 5,6-dihydro-1H-indole-2,4-dione derivatives

New Journal of Chemistry, Journal Year: 2024, Volume and Issue: 48(28), P. 12544 - 12552

Published: Jan. 1, 2024

Synthesis of tetrahydro indole-2,4-diones from readily available β-enaminones and glyoxal subsequent I 2 /DMSO-mediated oxidation/aromatization indole-2,4-dione to produce 4-hydroxyisatin derivatives.

Language: Английский

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From an Azaarene to the Spine of Fused Bicyclics: Cycloaddition-Induced Scaffold Hopping of 5-Hydroxypyrazoles

Research Square (Research Square), Journal Year: 2024, Volume and Issue: unknown

Published: July 9, 2024

Skeleton editing for heteroarenes, especially pyrazoles, is challenging and remains scarce due to these non-strained aromatics feature inert reactivities therefore relatively inactive perform a dearomatization/cleavage sequence. Herein, we disclose cycloaddition-induced scaffold hopping of 5-hydroxypyrazoles access pyrazolopyridopyridazin-6-one skeleton in single-operation protocol. By converting five-membered azaarene into five-unit spine 6/6 fused-bicyclics, this work has unlocked new ring-opening reactivity pyrrole core that involves formal C = N bond cleavage while retaining the highly reactive N-N resulting product. A [4 + 2] cycloaddition temporary dearomatized 5-hydroxypyrrole with anin situgenerated aza-1,3-diene follow-up oxidative C-N accounted domino pathway. library pyrazolopyridopyridazin-6-one, which are medicinally relevant nitrogen-atom-rich tricyclics, was obtained efficiently from readily available materials.

Language: Английский

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Synthesis, Characterization and Biological Evaluation of 3‐Oxo‐pyrimido[1,2‐b]indazoles

Advanced Synthesis & Catalysis, Journal Year: 2024, Volume and Issue: 366(19), P. 4055 - 4060

Published: July 20, 2024

Abstract The synthesis of substituted 3‐oxo‐pyrimido[1,2‐ b ]indazoles from 3‐aminoindazoles and ketones has been established. It involves one molecule two molecules via a [3+2+1] three‐component annulation process. 3‐Oxo‐pyrimido[1,2‐b]indazoles exhibit strong yellow fluorescence in various solvents. A wide range products have anti‐oxidant activities. Cytotoxicity studies indicate that compounds 3 , aa ab obvious effects on both HCT116 A549 cancer cell lines.

Language: Английский

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Divergent Synthesis of Pyrrolidone Fused Pyrimido[1,2-b]indazole through Selective Trapping of Enone Intermediate by 1H-indazol-3-amine

Chemical Communications, Journal Year: 2024, Volume and Issue: 60(72), P. 9781 - 9784

Published: Jan. 1, 2024

An oxidant-controlled divergent synthesis of a pyrrolidone fused pyrimido[1,2- b ]indazole skeleton was developed through selective cyclization an in situ generated enone intermediate and 1 H -indazol-3-amine.

Language: Английский

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I₂-Mediated [3 + 3] Annulation for the Construction of Indole-Pyrimidine-Pyrazole-Fused Tetracyclic Heteroarenes

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(20), P. 15164 - 15169

Published: Oct. 7, 2024

An I2-mediated annulation of 3-aminopyrazoles with indole-3-carboxaldehydes has been demonstrated for the first time. This tandem strategy allows facile construction indole-pyrimidine-pyrazole-fused tetracyclic heteroarenes that are otherwise inaccessible by existing methods. These fused heterocycles exhibited enhanced antifungal activities against Valsa mali and Botryosphaeria dothidea compared commercial Xemium fungicide.

Language: Английский

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Five-membered ring systems: With more than 1 N atom

Progress in heterocyclic chemistry, Journal Year: 2024, Volume and Issue: unknown, P. 211 - 257

Published: Jan. 1, 2024

Language: Английский

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