Application of Aryloximes as Solid-Phase Ketone Linkers
摘要:
In both solution and the solid phase, a variety of ketone oxime anions have been treated with 4-substituted-2-fluorobenzonitriles to give the corresponding nucleophilic aromatic substitution aryloxime adducts. Under aqueous acidic conditions, these adducts underwent cyclization to give the corresponding ketones. Suzuki and amide coupling reactions were also successfully performed on two resin-bound oximes followed by subsequent cyclorelease to give ketone product in good yields and purities.
A novel protocol for the efficient activation of the Beckmannrearrangement utilizing the readily available sulfuryl fluoride (SO2F2 gas) is reported. The substrate scope of this methodology has been demonstrated by 37 examples with good to nearly quantitative isolated yields in a short time. A tentative mechanism was proposed involving formation and elimination of sulfonyl ester.
报道了一种利用容易获得的硫酰氟(SO 2 F 2气体)有效激活贝克曼重排的新方案。该方法的底物范围已通过37个实例证明,并在短时间内获得了良好至近乎定量的分离产率。提出了一种尝试性的机制,涉及形成和消除磺酰基酯。
Visible-Light-Induced Beckmann Rearrangement by Organic Photoredox Catalysis
A facile and general strategy for efficient direct conversion of oximes to amides using an inexpensive organic photocatalyst and visible light is described. This radical Beckmannrearrangement can be performed under mild conditions. Various alkyl aryl ketoximes and diaryl ketoximes can be effectively converted into the corresponding amides in excellent yields.
dual-catalyzed cyanoalkylation reaction of enamides is illustrated. A wide scope of enamides and cycloketone oxime esters was well-tolerated, affording the synthetically versatile and geometrically defined β-cyanoalkylated enamide scaffolds. The synthetic practicality of this protocol was revealed by gram-scale reactions, further transformations of enamides, and late-stage modifications of biologically
A novel, efficient, and mild protocol for rearrangement of oximes to amides or hydrolyzing to ketone/aldehyde using a simple BODIPY dye as a photocatalyst and air as an oxidant via propagation reaction under visible-light irradiation is reported. The triplet excited state of BODIPY played a significant role in the catalytic process. It was found that the various substituted ketoximes, both with electron-withdrawing
In this update, we developed a mild, efficient and practical method using stable “F–SO2+” donor A as an environment friendly promoter for conversion of oximes to nitriles or amides via β-elimination or Beckmann rearrangement in excellent yields.
在本次更新中,我们利用稳定的 "F-SO2+"供体 A 作为环境友好型促进剂,开发出了一种温和、高效、实用的方法,可通过β-消除或贝克曼重排将肟转化为腈或酰胺,且收率极高。