Electrosynthesis of 1,2,3‐Benzotriazines through an Iodide‐Catalyzed Skeletal Editing of 3‐Aminoindazoles

Chemistry - A European Journal, Journal Year: 2024, Volume and Issue: unknown

Published: Aug. 19, 2024

Abstract This report describes an environmentally benign synthesis of 1,2,3‐benzotriazines through iodide‐catalyzed electro‐oxidative N ‐centered [1,2]‐rearrangement 3‐aminoindazoles. The developed method demonstrates the activation heteroatoms via electrochemically generated reactive iodide species without using any metal catalysts and peroxides. protocol features practical mild reaction conditions displays a wide substrate scope. Various mechanistic experiments cyclic voltammetric studies have been instrumental in elucidating mechanism, operating skeletal rearrangement

Language: Английский

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Photocatalyst‐Free Wavelength‐Dependant Sequential Ring Transformations of Pyrazolo[1,2‐a]pyrazolones

Advanced Synthesis & Catalysis, Journal Year: 2024, Volume and Issue: 366(21), P. 4441 - 4451

Published: Aug. 27, 2024

Abstract We report sequential wavelength‐selective photochemical transformations of 1‐alkenylpyrazolo[1,2‐ a ]pyrazolones to pyrazolo[1,2‐ ][1,2]diazepines or cyclobuta[ c ]pyrazolo[1,2‐ ]pyrazolones. Irradiation with visible‐light (blue LED, 457 nm) induced selective ‘ring switching’ transformation into ][1,2]diazepines, which underwent electrocyclisation yielding upon irradiation UV−A light (black 365 nm). Due the very narrow wavelength now available from OLED sources, formation either 5,7‐bicyclic 5,5,4‐tricyclic ring systems 5,5‐bicyclic starting material is possible by changing source. The took place under mild conditions in absence additives photocatalysts. Mechanistic studies indicate that these proceed through an excited triplet state substrate, followed homolytic C(1)−N(8) bond cleavage, intersystem crossing, and cyclization zwitterionic intermediate on ground potential energy surface. subsequent photoinduced disrotatory stereospecific 4π‐electrocyclization leads 3D‐rich products.

Language: Английский

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Direct oxygen insertion into C-C bond of styrenes with air

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

Published: Oct. 18, 2024

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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Skeletal Editing of Pyridines to Afford 1,2-Diazepines

Synfacts, Journal Year: 2024, Volume and Issue: 20(05), P. 0463 - 0463

Published: April 15, 2024

Key words pyridines - photochemistry 1,2-diazepines Hammett study diazanorcaradienes ring expansion late-stage functionalization

Language: Английский

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