The synthetic protocol for α-bromocarbonyl compounds via brominations

General methods have not been previously developed for the synthesis of sterically hindered α-SCF 3 -substituted carbonyl compounds using nucleophilic trifluoromethylthiolating reagents. Thus, we herein report sp 3 C−SCF 3 bond formation in hindered α-bromoamides containing 3-bromo-oxindoles and linear α-bromoamides using CuSCF 3 or AgSCF 3 under mild conditions to access sterically hindered α-SCF 3 -substituted amides. This transformation is applicable to not only 3-SCF 3 -substituted oxindoles but also primary and secondary amides and reveals a broad functional group tolerance. This method will benefit the fields of medicinal and agricultural chemistry.

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“…All solvents were purchased from Wako Pure Chemical Industries. α-Bromoamides were prepared according to the protocol described in refs , , .…”

Section: Methodsmentioning

confidence: 99%

Trifluoromethylthiolation of Hindered α-Bromoamides with Nucleophilic Trifluoromethylthiolating Reagents

et al. 2021

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“…Enantiomeric excesses were determined using an HPLC instrument with Chiralpak columns (Daicel Corporation, Tokyo, Japan), as indicated. α-Bromohydroxamates [ 32 , 33 , 34 ], 2-amino-β-nitrostyrens [ 24 ], and organocatalysts [ 35 , 36 , 37 ] were prepared according to the literature.…”

Section: Methodsmentioning

confidence: 99%

Stereoselective [4+3]-Cycloaddition of 2-Amino-β-nitrostyrenes with Azaoxyallyl Cations to Access Functionalized 1,4-Benzodiazepin-3-ones

Kim,

Kim

2024

Molecules

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The 1,4-benzodiazepine structural framework is a fascinating element commonly found in biologically active and pharmaceutically relevant compounds. A highly efficient method for synthesizing 1,4-benzodiazepin-3-ones is described, involving a [4+3]-cycloaddition reaction between 2-amino-β-nitrostyrenes and α-bromohydroxamate, with Cs2CO3 used as a base. This process yielded the desired 1,4-benzodiazepines in good yields. Furthermore, an organocatalytic asymmetric [4+3]-cycloaddition was successfully accomplished using a bifunctional squaramide-based catalyst. This approach enabled the enantioselective synthesis of chiral 1,4-benzodiazepines with commendable yields and moderate enantioselectivities, reaching up to 80% yield and 72% ee.

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“…The resulting crude -bromo acyl bromide was used in this form for the next step. 26 The amine (6.0 mmol) and Et3N (1.67 mL, 12 mmol) were dissolved in 30 mL dry DCM (0.5 M) in a 100 mL round bottom flask equipped with a magnetic stirring bar. After stirring at 0 o C for 5 min, DMAP (73.2 mg, 0.6 mmol) was added into the mixture, followed by dropwise addition of the prepared -bromo acyl bromide at 0 o C. The reaction mixture was stirred at 25 °C for 12 h. It was then quenched with water (10 mL).…”

Section: Methods Bmentioning

confidence: 99%

Iron-Catalyzed Benzene Ring Expansion of α-Azido-N-phenylamides

Wei¹,

Jiang²,

Liang³

et al. 2022

Synthesis

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Nitrenoid-mediated C–H insertion and cycloaddition reactions are gaining increasing importance in modern organic synthesis. However, the nitrene-mediated benzene ring expansion, which constitutes a potent tool for breaking the benzene ring, has sparely been explored for synthetic purposes. Herein we report that nitrene cycloaddition to the benzene ring can be enabled intramolecularly by iron catalysis. By using FeCl2 and N-heterocyclic carbene SIPr HCl as the catalyst, α-azido-N-phenylamides can be converted to 1,3-dihydro-2H-azepin-2-ones in good yield through a novel skeleton rearrangement. The rearrangement features a cascade of nitrene cycloaddition, C–N cleavage, water addition and electrocyclic ring-opening. In case that the N-phenyl ring is substituted with a methoxy group at the meta or para position, azepin-2-one-fused imidazolinones can also be obtained. The present reactions provide an effective method for benzene ring expansion as well as for the preparation of azepin-2-one compounds.

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The synthetic protocol for α-bromocarbonyl compounds via brominations

Cited by 9 publications

References 29 publications

Trifluoromethylthiolation of Hindered α-Bromoamides with Nucleophilic Trifluoromethylthiolating Reagents

Trifluoromethylthiolation of Hindered α-Bromoamides with Nucleophilic Trifluoromethylthiolating Reagents

Stereoselective [4+3]-Cycloaddition of 2-Amino-β-nitrostyrenes with Azaoxyallyl Cations to Access Functionalized 1,4-Benzodiazepin-3-ones

Iron-Catalyzed Benzene Ring Expansion of α-Azido-N-phenylamides

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