Ionic Liquid Beckmann rearrangement

Not much attention has been directed to isomerisation and rearrangement reactions in ionic liquids. Beckmann rearrangements of ketoximes have been performed in neat ionic liquids catalysed by phosphorus(V) chlorides and oxides1 301 and Fries rearrangements of phenylbenzoates have been carried out in chloroaluminate ionic liquids with moderate to good selectivity.1 311... [Pg.213]

Beckmann rearrangements of several ketoximes were performed in room-temperature ionic liquids based on l,3-dialkylimida2olium or alkylpyridinium salts containing phosphorus compounds (such as PCI5) by Deng and Peng [59] (Scheme 5.1-31, BP = 1-butylpyridinium). Turnover numbers of up to 6.6 were observed, but the authors did not mention whether the ionic liquid could be reused. [Pg.189]

Lee and colleagues studied the ionic-liquid-mediated Beckmann rearrangement under microwaves (equation 96). They screened several ionic liquids and investigated the amount of sulfuric acid needed as catalyst. The microwave methodology was found to be superior to analogous conventional heating. All the ionic liquids tested worked well in the microwave and only 5 mol% sulfuric acid was needed. The BMIM ionic liquids ([BMIM]PFg, [BMIM]Bp4, [BMIMJSbFg and [BMIMJOTf) were found to be thermally stable. [Pg.410]

To explain the difficulties encountered in the reuse of sulfonyl chloride functionalized ionic liquids during Beckmann rearrangement, Deng and colleagues proposed a mechanism for rearrangement of cyclohexanone oxime (equation 97). [Pg.411]

Alternative purification protocols are available. Zhaolin Sun of Lanzhou University reports (Tetrahedron Lett. 45 2681,2004) that the ionic liquid TISC was specifically designed to promote Beckmann rearrangement. TISC is not soluble in water, so the product caprolactam was easily removed from the ionic liquid by extraction with water. [Pg.15]

A -Butylpyridinium tetrafluoroborate, containing dissolved phosphorus pentachloride, allows catalytic Beckmann rearrangement of cyclohexanone oxime giving e-caprolactam with good conversion and selectivity <2001TL403>. The same ionic liquid containing dissolved ytterbium(m) trifluoromethanesulfonate was used to perform Friedel-Crafts acylation of furan and thiophene <2005JIG398>. [Pg.320]

Gui H Z, Deng Y Q, Hu Z D, et al. A novel task-specific ionic liquid for beckmann rearrangement A simple and effective way for product separation. Tetrahedron Lett. 2004. 45, 2681-2683. [Pg.475]

Guo S, Du Z, Zhang S, et al. Clean beckmann rearrangement of cyclohexanone oxime in caprolactambased brpnsted acidic ionic liquids. Green Chem. 2006. 8, 296-300. [Pg.477]

Lee, J. K., Kim, D.-C., Song, C. E., Lee, S.-g. Thermal behaviors of ionic liquids under microwave irradiation and their application on microwave-assisted catalytic Beckmann rearrangement of ketoximes. Synth. Commun. 2003, 33, 2301-2307. [Pg.548]

Microwave and Ionic Liquid-assisted Beckmann Rearrangement... [Pg.339]

Ionic Liquids in Conjunction with Microwave Activation 341 Tab. 7.5. M icrowave-assisted Beckmann rearrangement using ionic liquids. [Pg.341]

Peng J, Deng Y (2001) Catalytic Beckmann rearrangement of ketoximes in ionic Liquids. Tetrahedron Lett 42 403 05... [Pg.229]

Verevkin SP, Emel yanenko VN, Toktonov AV, Goodrich P, Hardacre C (2009) Thermochemistry of ionic liquid-catalyzed reactions theoretical and experimental study of the Beckmann rearrangement—kinetic or thermodynamic control Ind Eng Chem Res 48(22) 9809-9816... [Pg.230]

The cited conditions for the preparation and rearrangement of oxime have been selected among many others reported in the literature and patents. For specific oximes, the Beckmann rearrangement is catalyzed by zeolites or nanoporous materials in ionic liquids in the presence of Co(III), Mn(III) or Fe(III) salts [4]. [Pg.175]

Ren, R.X., Zueva, D.L. Ou, W. (2001). Formation of e-Caprolactam via Catalytic Beckmann Rearrangement Using P2O5 in Ionic Liquids, Tetrahedron Lett., 42, pp. 8441- 8443 Ross, J. Xiao, J. (2002) Friedel-Crafts Acylation Reactions Using Metal Triflates in Ionic Liquids, Green Chem., 4, pp. 129-133... [Pg.270]

Biodegradable imidazolium-based ionic liquid solvents have been applied effectively to cyanuric-chloride-catalysed Beckmann rearrangement of ketoximes. Conflicting views of the mechanism of aldoxime to amide rearrangements catalysed by metals have been reviewed and whether or not a universal mechanism applies has been discussed in the light of new evidence. ... [Pg.14]

A new and efficient microwave induced bismuth trichloride catalyzed Beckmann rearrangement of oximes in the solid state has been achieved by Thakur et al. (2007). Beckmann rearrangement of aryl ketoximes catalyzed by In(OTf)3 gave amides in ionic liquid under microwave irradiation. These aryl ketoximes were converted to corresponding amides in good yields within very short times (10-270 sec). The catalyst and the ionic liquid were easily recovered and reused (Sugamoto et al, 2011). [Pg.211]

Microwave-assisted Beckmann rearrangement of ketoximes was investigated using stannous (II) chloride in ionic liquid as an efficient catalyst (Niralwad et al, 2011). They carried out conversion of keto halides to lactams by means of sequential azidation and intramolecular Schmidt reaction in a combined flow format. [Pg.212]

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