K<sub>3</sub>PO<sub>4</sub>–Mediated Synthesis of Chromeno–[3,4‐<i>c</i>]isoxazole From 3–Nitro–2<i>H</i>–chromene and <i>α</i>–Chloro Aldehyde via Michael addition/C–Cl bond cleavage/deformylation as Key Fragmentation Sequences DOI

Aniruddh Pratap,

Pushpendra Mani Shukla,

Santanab Giri

и другие.

Advanced Synthesis & Catalysis, Год журнала: 2024, Номер 366(19), С. 4122 - 4131

Опубликована: Июль 12, 2024

Abstract Here we report a transition metal– and oxidant–free annulation cascade method for the synthesis of chromeno–isoxazoles. The reaction involves easily accessible starting materials, 3‐nitro‐2 H ‐chromene α ‐chloro aldehyde, yielding structurally intriguing framework, chromeno[3,4‐ c ]isoxazoles employed by tripotassium phosphate as base. isoxazole ring construction over 2 –chromene unit is believed to occur via series multiple sequences. Here, enolate generation/Michael addition/C−Cl bond cleavage/oxy–anionic addition reactive tethered‐aldehyde/deformylation retro–C−C N−O cleavages are most possible sequences which furnish desired end–product in good chemical yields. one‐pot at mild conditions, supported experimental results few control experiments including DFT studies. This process exhibits broad substrates scope illustrating functional group compatibility towards both nitrochromenes aldehydes, thus prove be general efficient protocol chromeno[3,4– ]isoxazoles. Overall, use nitrochromene limiting reagent, noteworthy tolerance, scalability great applications like chiral pool strategy enantioenriched chromeno‐isoxazole additional features.

Язык: Английский

K<sub>3</sub>PO<sub>4</sub>–Mediated Synthesis of Chromeno–[3,4‐<i>c</i>]isoxazole From 3–Nitro–2<i>H</i>–chromene and <i>α</i>–Chloro Aldehyde via Michael addition/C–Cl bond cleavage/deformylation as Key Fragmentation Sequences DOI

Aniruddh Pratap,

Pushpendra Mani Shukla,

Santanab Giri

и другие.

Advanced Synthesis & Catalysis, Год журнала: 2024, Номер 366(19), С. 4122 - 4131

Опубликована: Июль 12, 2024

Abstract Here we report a transition metal– and oxidant–free annulation cascade method for the synthesis of chromeno–isoxazoles. The reaction involves easily accessible starting materials, 3‐nitro‐2 H ‐chromene α ‐chloro aldehyde, yielding structurally intriguing framework, chromeno[3,4‐ c ]isoxazoles employed by tripotassium phosphate as base. isoxazole ring construction over 2 –chromene unit is believed to occur via series multiple sequences. Here, enolate generation/Michael addition/C−Cl bond cleavage/oxy–anionic addition reactive tethered‐aldehyde/deformylation retro–C−C N−O cleavages are most possible sequences which furnish desired end–product in good chemical yields. one‐pot at mild conditions, supported experimental results few control experiments including DFT studies. This process exhibits broad substrates scope illustrating functional group compatibility towards both nitrochromenes aldehydes, thus prove be general efficient protocol chromeno[3,4– ]isoxazoles. Overall, use nitrochromene limiting reagent, noteworthy tolerance, scalability great applications like chiral pool strategy enantioenriched chromeno‐isoxazole additional features.

Язык: Английский

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